Back-up Rings

Back-up rings (aka anti-extrusion rings) protect o’rings and help prevent extrusion in high pressure applications.

Back-up rings

Back-up rings (aka anti-extrusion rings) protect o’rings and help prevent extrusion in high pressure applications by closing the clearance gap and reducing friction by trapping lubricant in the area of the seal. Double acting applications (using bi-directional pressure) require the use of two back-up rings, one on either side of the o’ring.
In single acting applications (single sided pressure) where only one back-up ring is required, the back-up is located on the low pressure side of the o’ring; although it is often recommended that two back-ups be used in single acting applications to mitigate the possibility of installing the back-up on the wrong side of the o’ring.

Sealing Australia stocks a wide range of back-up rings to suit imperial and JIS metric sized o’rings. Compounds available: 90 Duro nitrile, 90 Duro Viton, Teflon and polyurethane.

Imperial Contoured Back-up Sizes

Contoured back-ups are usually made of rubber and mimic the shape of an o’ring on one side to minimises distortion of the o’ring while under pressure.

Available in NBR90 and FKM90 (Viton)

1/16″ Contoured Back-up

Size reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
004	.096	.005	.053	.003	2.44	0.13	1.35	0.08
005	.127	.005	.053	.003	3.23	0.13	1.35	0.08
006	.140	.005	.053	.003	3.56	0.13	1.35	0.08
007	.171	.005	.053	.003	4.34	0.13	1.35	0.08
008	.202	.005	.053	.003	5.13	0.13	1.35	0.08
009	.234	.005	.053	.003	5.94	0.13	1.35	0.08
010	.265	.005	.053	.003	6.73	0.13	1.35	0.08
011	.327	.005	.053	.003	8.31	0.13	1.35	0.08
012	.390	.005	.053	.003	9.91	0.13	1.35	0.08
013	.455	.005	.053	.003	11.56	0.13	1.35	0.08
014	.518	.005	.053	.003	13.16	0.13	1.35	0.08
015	.580	.007	.053	.003	14.73	0.18	1.35	0.08
016	.643	.009	.053	.003	16.33	0.23	1.35	0.08
017	.705	.009	.053	.003	17.91	0.23	1.35	0.08
018	.768	.009	.053	.003	19.51	0.23	1.35	0.08
019	.830	.009	.053	.003	21.08	0.23	1.35	0.08
020	.893	.009	.053	.003	22.68	0.23	1.35	0.08
021	.955	.009	.053	.003	24.26	0.23	1.35	0.08
022	1.018	.010	.053	.003	25.86	0.25	1.35	0.08
023	1.080	.010	.053	.003	27.43	0.25	1.35	0.08
024	1.143	.010	.053	.003	29.03	0.25	1.35	0.08
025	1.205	.011	.053	.003	30.61	0.28	1.35	0.08
026	1.268	.011	.053	.003	32.21	0.28	1.35	0.08
027	1.330	.011	.053	.003	33.78	0.28	1.35	0.08
028	1.393	.013	.053	.003	35.38	0.33	1.35	0.08
029	1.518	.013	.053	.003	38.56	0.33	1.35	0.08
030	1.643	.013	.053	.003	41.73	0.33	1.35	0.08
031	1.768	.015	.053	.003	44.91	0.38	1.35	0.08
032	1.893	.015	.053	.003	48.08	0.38	1.35	0.08
033	2.018	.018	.053	.003	51.26	0.46	1.35	0.08
034	2.143	.018	.053	.003	54.43	0.46	1.35	0.08
035	2.268	.018	.053	.003	57.61	0.46	1.35	0.08
036	2.393	.018	.053	.003	60.78	0.46	1.35	0.08
037	2.518	.018	.053	.003	63.96	0.46	1.35	0.08
038	2.643	.020	.053	.003	67.13	0.51	1.35	0.08
039	2.768	.020	.053	.003	70.31	0.51	1.35	0.08
040	2.893	.020	.053	.003	73.48	0.51	1.35	0.08
041	3.018	.024	.053	.003	76.66	0.61	1.35	0.08
042	3.268	.024	.053	.003	83.01	0.61	1.35	0.08
043	3.518	.024	.053	.003	89.36	0.61	1.35	0.08
044	3.768	.027	.053	.003	95.71	0.69	1.35	0.08
045	4.018	.027	.053	.003	102.06	0.69	1.35	0.08
046	4.268	.030	.053	.003	108.41	0.76	1.35	0.08
047	4.518	.030	.053	.003	114.76	0.76	1.35	0.08
048	4.768	.030	.053	.003	121.11	0.76	1.35	0.08
049	5.018	.037	.053	.003	127.46	0.94	1.35	0.08
050	5.268	.037	.053	.003	133.81	0.94	1.35	0.08

3/32″ Contoured Back-up

Size reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
102	.077	.005	.086	.003	1.96	0.13	2.18	0.08
103	.109	.005	.086	.003	2.77	0.13	2.18	0.08
104	.140	.005	.086	.003	3.56	0.13	2.18	0.08
105	.171	.005	.086	.003	4.34	0.13	2.18	0.08
106	.202	.005	.086	.003	5.13	0.13	2.18	0.08
107	.234	.005	.086	.003	5.94	0.13	2.18	0.08
108	.265	.005	.086	.003	6.73	0.13	2.18	0.08
109	.327	.005	.086	.003	8.31	0.13	2.18	0.08
110	.390	.005	.086	.003	9.91	0.13	2.18	0.08
111	.452	.005	.086	.003	11.48	0.13	2.18	0.08
112	.515	.005	.086	.003	13.08	0.13	2.18	0.08
113	.577	.007	.086	.003	14.66	0.18	2.18	0.08
114	.640	.009	.086	.003	16.26	0.23	2.18	0.08
115	.702	.009	.086	.003	17.83	0.23	2.18	0.08
116	.765	.009	.086	.003	19.43	0.23	2.18	0.08
117	.831	.010	.086	.003	21.11	0.25	2.18	0.08
118	.893	.010	.086	.003	22.68	0.25	2.18	0.08
119	.956	.010	.086	.003	24.28	0.25	2.18	0.08
120	1.018	.010	.086	.003	25.86	0.25	2.18	0.08
121	1.081	.010	.086	.003	27.46	0.25	2.18	0.08
122	1.143	.010	.086	.003	29.03	0.25	2.18	0.08
123	1.206	.012	.086	.003	30.63	0.30	2.18	0.08
124	1.268	.012	.086	.003	32.21	0.30	2.18	0.08
125	1.331	.012	.086	.003	33.81	0.30	2.18	0.08
126	1.393	.012	.086	.003	35.38	0.30	2.18	0.08
127	1.456	.012	.086	.003	36.98	0.30	2.18	0.08
128	1.518	.012	.086	.003	38.56	0.30	2.18	0.08
129	1.581	.015	.086	.003	40.16	0.38	2.18	0.08
130	1.643	.015	.086	.003	41.73	0.38	2.18	0.08
131	1.706	.015	.086	.003	43.33	0.38	2.18	0.08
132	1.768	.015	.086	.003	44.91	0.38	2.18	0.08
133	1.831	.015	.086	.003	46.51	0.38	2.18	0.08
134	1.893	.015	.086	.003	48.08	0.38	2.18	0.08
135	1.956	.017	.086	.003	49.68	0.43	2.18	0.08
136	2.018	.017	.086	.003	51.26	0.43	2.18	0.08
137	2.081	.017	.086	.003	52.86	0.43	2.18	0.08
138	2.143	.017	.086	.003	54.43	0.43	2.18	0.08
139	2.206	.017	.086	.003	56.03	0.43	2.18	0.08
140	2.268	.017	.086	.003	57.61	0.43	2.18	0.08
141	2.331	.020	.086	.003	59.21	0.51	2.18	0.08
142	2.393	.020	.086	.003	60.78	0.51	2.18	0.08
143	2.456	.020	.086	.003	62.38	0.51	2.18	0.08
144	2.518	.020	.086	.003	63.96	0.51	2.18	0.08
145	2.581	.020	.086	.003	65.56	0.51	2.18	0.08
146	2.643	.020	.086	.003	67.13	0.51	2.18	0.08
147	2.706	.022	.086	.003	68.73	0.56	2.18	0.08
148	2.768	.022	.086	.003	70.31	0.56	2.18	0.08
149	2.831	.022	.086	.003	71.91	0.56	2.18	0.08
150	2.893	.022	.086	.003	73.48	0.56	2.18	0.08
151	3.018	.024	.086	.003	76.66	0.61	2.18	0.08
152	3.268	.024	.086	.003	83.01	0.61	2.18	0.08
153	3.518	.024	.086	.003	89.36	0.61	2.18	0.08
154	3.768	.028	.086	.003	95.71	0.71	2.18	0.08
155	4.018	.028	.086	.003	102.06	0.71	2.18	0.08
156	4.268	.030	.086	.003	108.41	0.76	2.18	0.08
157	4.518	.030	.086	.003	114.76	0.76	2.18	0.08
158	4.768	.030	.086	.003	121.11	0.76	2.18	0.08
159	5.018	.035	.086	.003	127.46	0.89	2.18	0.08
160	5.268	.035	.086	.003	133.81	0.89	2.18	0.08
161	5.518	.035	.086	.003	140.16	0.89	2.18	0.08
162	5.768	.035	.086	.003	146.51	0.89	2.18	0.08
163	6.018	.035	.086	.003	152.86	0.89	2.18	0.08
164	6.268	.040	.086	.003	159.21	1.02	2.18	0.08
165	6.518	.040	.086	.003	165.56	1.02	2.18	0.08
166	6.768	.040	.086	.003	171.91	1.02	2.18	0.08
167	7.018	.040	.086	.003	178.26	1.02	2.18	0.08
168	7.268	.045	.086	.003	184.61	1.14	2.18	0.08
169	7.518	.045	.086	.003	190.96	1.14	2.18	0.08
170	7.768	.045	.086	.003	197.31	1.14	2.18	0.08
171	8.018	.045	.086	.003	203.66	1.14	2.18	0.08
172	8.268	.050	.086	.003	210.01	1.27	2.18	0.08
173	8.518	.050	.086	.003	216.36	1.27	2.18	0.08
174	8.768	.050	.086	.003	222.71	1.27	2.18	0.08
175	9.018	.050	.086	.003	229.06	1.27	2.18	0.08
176	9.268	.055	.086	.003	235.41	1.40	2.18	0.08
177	9.518	.055	.086	.003	241.76	1.40	2.18	0.08
178	9.768	.055	.086	.003	248.11	1.40	2.18	0.08

1/8″ Contoured Back-up

Size reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
201	.202	.005	.118	.004	5.13	0.13	3.00	0.10
202	.265	.005	.118	.004	6.73	0.13	3.00	0.10
203	.327	.005	.118	.004	8.31	0.13	3.00	0.10
204	.390	.005	.118	.004	9.91	0.13	3.00	0.10
205	.455	.005	.118	.004	11.56	0.13	3.00	0.10
206	.518	.005	.118	.004	13.16	0.13	3.00	0.10
207	.580	.007	.118	.004	14.73	0.18	3.00	0.10
208	.643	.009	.118	.004	16.33	0.23	3.00	0.10
209	.705	.010	.118	.004	17.91	0.23	3.00	0.10
210	.766	.010	.118	.004	19.46	0.25	3.00	0.10
211	.828	.010	.118	.004	21.03	0.25	3.00	0.10
212	.891	.010	.118	.004	22.63	0.25	3.00	0.10
213	.953	.010	.118	.004	24.21	0.25	3.00	0.10
214	1.016	.010	.118	.004	25.81	0.25	3.00	0.10
215	1.078	.010	.118	.004	27.38	0.25	3.00	0.10
216	1.141	.012	.118	.004	28.98	0.30	3.00	0.10
217	1.203	.012	.118	.004	30.56	0.30	3.00	0.10
218	1.266	.012	.118	.004	32.16	0.30	3.00	0.10
219	1.334	.012	.118	.004	33.88	0.30	3.00	0.10
220	1.397	.012	.118	.004	35.48	0.30	3.00	0.10
221	1.459	.012	.118	.004	37.06	0.30	3.00	0.10
222	1.522	.015	.118	.004	38.66	0.38	3.00	0.10
223	1.647	.015	.118	.004	41.83	0.38	3.00	0.10
224	1.772	.015	.118	.004	45.01	0.38	3.00	0.10
225	1.897	.018	.118	.004	48.18	0.46	3.00	0.10
226	2.022	.018	.118	.004	51.36	0.46	3.00	0.10
227	2.147	.018	.118	.004	54.53	0.46	3.00	0.10
228	2.272	.020	.118	.004	57.71	0.51	3.00	0.10
229	2.397	.020	.118	.004	60.89	0.51	3.00	0.10
230	2.522	.020	.118	.004	64.06	0.51	3.00	0.10
231	2.631	.020	.118	.004	66.83	0.51	3.00	0.10
232	2.756	.024	.118	.004	70.00	0.61	3.00	0.10
233	2.881	.024	.118	.004	73.18	0.61	3.00	0.10
234	3.006	.024	.118	.004	76.35	0.61	3.00	0.10
235	3.131	.024	.118	.004	79.53	0.61	3.00	0.10
236	3.256	.024	.118	.004	82.70	0.61	3.00	0.10
237	3.381	.024	.118	.004	85.88	0.61	3.00	0.10
238	3.506	.024	.118	.004	89.05	0.61	3.00	0.10
239	3.631	.028	.118	.004	92.23	0.71	3.00	0.10
240	3.756	.028	.118	.004	95.40	0.71	3.00	0.10
241	3.881	.028	.118	.004	98.58	0.71	3.00	0.10
242	4.006	.028	.118	.004	101.75	0.71	3.00	0.10
243	4.131	.028	.118	.004	104.93	0.71	3.00	0.10
244	4.256	.030	.118	.004	108.10	0.76	3.00	0.10
245	4.381	.030	.118	.004	111.28	0.76	3.00	0.10
246	4.506	.030	.118	.004	114.45	0.76	3.00	0.10
247	4.631	.030	.118	.004	117.63	0.76	3.00	0.10
248	4.768	.030	.118	.004	121.11	0.76	3.00	0.10
249	4.893	.035	.118	.004	124.28	0.89	3.00	0.10
250	5.018	.035	.118	.004	127.46	0.89	3.00	0.10
251	5.143	.035	.118	.004	130.63	0.89	3.00	0.10
252	5.268	.035	.118	.004	133.81	0.89	3.00	0.10
253	5.393	.035	.118	.004	136.98	0.89	3.00	0.10
254	5.518	.035	.118	.004	140.16	0.89	3.00	0.10
255	5.643	.035	.118	.004	143.33	0.89	3.00	0.10
256	5.768	.035	.118	.004	146.51	0.89	3.00	0.10
257	5.893	.035	.118	.004	149.68	0.89	3.00	0.10
258	6.018	.035	.118	.004	152.86	0.89	3.00	0.10
259	6.268	.040	.118	.004	159.21	1.02	3.00	0.10
260	6.518	.040	.118	.004	165.56	1.02	3.00	0.10
261	6.768	.040	.118	.004	171.91	1.02	3.00	0.10
262	7.018	.040	.118	.004	178.26	1.02	3.00	0.10
263	7.268	.045	.118	.004	184.61	1.14	3.00	0.10
264	7.518	.045	.118	.004	190.96	1.14	3.00	0.10
265	7.768	.045	.118	.004	197.31	1.14	3.00	0.10
266	8.018	.045	.118	.004	203.66	1.14	3.00	0.10
267	8.268	.050	.118	.004	210.01	1.27	3.00	0.10
268	8.518	.050	.118	.004	216.36	1.27	3.00	0.10
269	8.768	.050	.118	.004	222.71	1.27	3.00	0.10
270	9.018	.050	.118	.004	229.06	1.27	3.00	0.10
271	9.268	.055	.118	.004	235.41	1.40	3.00	0.10
272	9.518	.055	.118	.004	241.76	1.40	3.00	0.10
273	9.768	.055	.118	.004	248.11	1.40	3.00	0.10
274	10.018	.055	.118	.004	254.46	1.40	3.00	0.10
275	10.518	.055	.118	.004	267.16	1.40	3.00	0.10
276	11.018	.065	.118	.004	279.86	1.65	3.00	0.10
277	11.518	.065	.118	.004	292.56	1.65	3.00	0.10
278	12.018	.065	.118	.004	305.26	1.65	3.00	0.10
279	13.018	.065	.118	.004	330.66	1.65	3.00	0.10
280	14.018	.065	.118	.004	356.06	1.65	3.00	0.10
281	15.018	.065	.118	.004	381.46	1.65	3.00	0.10
282	15.989	.075	.118	.004	406.12	1.91	3.00	0.10
283	16.989	.080	.118	.004	431.52	2.03	3.00	0.10
284	17.989	.085	.118	.004	456.92	2.16	3.00	0.10

3/16″ Contoured Back-up

Size reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
309	.450	.005	.183	.005	11.43	0.13	4.65	0.13
310	.513	.005	.183	.005	13.03	0.13	4.65	0.13
311	.575	.007	.183	.005	14.61	0.18	4.65	0.13
312	.638	.009	.183	.005	16.21	0.23	4.65	0.13
313	.700	.009	.183	.005	17.78	0.23	4.65	0.13
314	.763	.010	.183	.005	19.38	0.25	4.65	0.13
315	.825	.010	.183	.005	20.96	0.25	4.65	0.13
316	.888	.010	.183	.005	22.56	0.25	4.65	0.13
317	.950	.010	.183	.005	24.13	0.25	4.65	0.13
318	1.013	.010	.183	.005	25.73	0.25	4.65	0.13
319	1.075	.010	.183	.005	27.31	0.25	4.65	0.13
320	1.138	.012	.183	.005	28.91	0.30	4.65	0.13
321	1.200	.012	.183	.005	30.48	0.30	4.65	0.13
322	1.263	.012	.183	.005	32.08	0.30	4.65	0.13
323	1.316	.012	.183	.005	33.43	0.30	4.65	0.13
324	1.388	.012	.183	.005	35.26	0.30	4.65	0.13
325	1.513	.015	.183	.005	38.43	0.38	4.65	0.13
326	1.638	.015	.183	.005	41.61	0.38	4.65	0.13
327	1.763	.015	.183	.005	44.78	0.38	4.65	0.13
328	1.888	.015	.183	.005	47.96	0.38	4.65	0.13
329	2.013	.018	.183	.005	51.13	0.46	4.65	0.13
330	2.138	.018	.183	.005	54.31	0.46	4.65	0.13
331	2.268	.018	.183	.005	57.61	0.46	4.65	0.13
332	2.393	.018	.183	.005	60.78	0.46	4.65	0.13
333	2.518	.020	.183	.005	63.96	0.51	4.65	0.13
334	2.643	.020	.183	.005	67.13	0.51	4.65	0.13
335	2.768	.020	.183	.005	70.31	0.51	4.65	0.13
336	2.893	.020	.183	.005	73.48	0.51	4.65	0.13
337	3.018	.024	.183	.005	76.66	0.61	4.65	0.13
338	3.143	.024	.183	.005	79.83	0.61	4.65	0.13
339	3.273	.024	.183	.005	83.13	0.61	4.65	0.13
340	3.398	.024	.183	.005	86.31	0.61	4.65	0.13
341	3.523	.024	.183	.005	89.48	0.61	4.65	0.13
342	3.648	.028	.183	.005	92.66	0.71	4.65	0.13
343	3.773	.028	.183	.005	95.83	0.71	4.65	0.13
344	3.898	.028	.183	.005	99.01	0.71	4.65	0.13
345	4.028	.028	.183	.005	102.31	0.71	4.65	0.13
346	4.153	.028	.183	.005	105.49	0.71	4.65	0.13
347	4.278	.030	.183	.005	108.66	0.76	4.65	0.13
348	4.403	.030	.183	.005	111.84	0.76	4.65	0.13
349	4.528	.030	.183	.005	115.01	0.76	4.65	0.13
350	4.653	.030	.183	.005	118.19	0.76	4.65	0.13
351	4.778	.030	.183	.005	121.36	0.76	4.65	0.13
352	4.903	.030	.183	.005	124.54	0.76	4.65	0.13
353	5.028	.037	.183	.005	127.71	0.94	4.65	0.13
354	5.153	.037	.183	.005	130.89	0.94	4.65	0.13
355	5.278	.037	.183	.005	134.06	0.94	4.65	0.13
356	5.403	.037	.183	.005	137.24	0.94	4.65	0.13
357	5.528	.037	.183	.005	140.41	0.94	4.65	0.13
358	5.653	.037	.183	.005	143.59	0.94	4.65	0.13
359	5.778	.037	.183	.005	146.76	0.94	4.65	0.13
360	5.903	.037	.183	.005	149.94	0.94	4.65	0.13
361	6.028	.037	.183	.005	153.11	0.94	4.65	0.13
362	6.278	.040	.183	.005	159.46	1.02	4.65	0.13
363	6.528	.040	.183	.005	165.81	1.02	4.65	0.13
364	6.778	.040	.183	.005	172.16	1.02	4.65	0.13
365	7.028	.040	.183	.005	178.51	1.02	4.65	0.13
366	7.278	.045	.183	.005	184.86	1.14	4.65	0.13
367	7.528	.045	.183	.005	191.21	1.14	4.65	0.13
368	7.778	.045	.183	.005	197.56	1.14	4.65	0.13
369	8.028	.045	.183	.005	203.91	1.14	4.65	0.13
370	8.278	.050	.183	.005	210.26	1.27	4.65	0.13
371	8.528	.050	.183	.005	216.61	1.27	4.65	0.13
372	8.778	.050	.183	.005	222.96	1.27	4.65	0.13
373	9.028	.050	.183	.005	229.31	1.27	4.65	0.13
374	9.278	.055	.183	.005	235.66	1.40	4.65	0.13
375	9.528	.055	.183	.005	242.01	1.40	4.65	0.13
376	9.778	.055	.183	.005	248.36	1.40	4.65	0.13
377	10.028	.055	.183	.005	254.71	1.40	4.65	0.13
378	10.528	.060	.183	.005	267.41	1.52	4.65	0.13
379	11.028	.060	.183	.005	280.11	1.52	4.65	0.13
380	11.528	.065	.183	.005	292.81	1.65	4.65	0.13
381	12.028	.065	.183	.005	305.51	1.65	4.65	0.13
382	13.028	.065	.183	.005	330.91	1.65	4.65	0.13
383	14.028	.070	.183	.005	356.31	1.78	4.65	0.13
384	15.028	.070	.183	.005	381.71	1.78	4.65	0.13
385	16.008	.075	.183	.005	406.60	1.91	4.65	0.13
386	17.008	.080	.183	.005	432.01	2.03	4.65	0.13
387	18.008	.085	.183	.005	457.40	2.16	4.65	0.13
388	19.006	.090	.183	.005	482.75	2.29	4.65	0.13
389	20.006	.095	.183	.005	508.15	2.41	4.65	0.13
390	21.006	.095	.183	.005	533.55	2.41	4.65	0.13
391	22.006	.100	.183	.005	558.95	2.54	4.65	0.13
392	22.993	.105	.183	.005	584.02	2.67	4.65	0.13
393	23.993	.110	.183	.005	609.42	2.79	4.65	0.13
394	24.993	.115	.183	.005	634.82	2.92	4.65	0.13
395	25.993	.120	.183	.005	660.22	3.05	4.65	0.13

1/4″ Contoured Back-up

3/16″ Contoured Back-up

Size reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
309	.450	.005	.183	.005	11.43	0.13	4.65	0.13
310	.513	.005	.183	.005	13.03	0.13	4.65	0.13
311	.575	.007	.183	.005	14.61	0.18	4.65	0.13
312	.638	.009	.183	.005	16.21	0.23	4.65	0.13
313	.700	.009	.183	.005	17.78	0.23	4.65	0.13
314	.763	.010	.183	.005	19.38	0.25	4.65	0.13
315	.825	.010	.183	.005	20.96	0.25	4.65	0.13
316	.888	.010	.183	.005	22.56	0.25	4.65	0.13
317	.950	.010	.183	.005	24.13	0.25	4.65	0.13
318	1.013	.010	.183	.005	25.73	0.25	4.65	0.13
319	1.075	.010	.183	.005	27.31	0.25	4.65	0.13
320	1.138	.012	.183	.005	28.91	0.30	4.65	0.13
321	1.200	.012	.183	.005	30.48	0.30	4.65	0.13
322	1.263	.012	.183	.005	32.08	0.30	4.65	0.13
323	1.316	.012	.183	.005	33.43	0.30	4.65	0.13
324	1.388	.012	.183	.005	35.26	0.30	4.65	0.13
325	1.513	.015	.183	.005	38.43	0.38	4.65	0.13
326	1.638	.015	.183	.005	41.61	0.38	4.65	0.13
327	1.763	.015	.183	.005	44.78	0.38	4.65	0.13
328	1.888	.015	.183	.005	47.96	0.38	4.65	0.13
329	2.013	.018	.183	.005	51.13	0.46	4.65	0.13
330	2.138	.018	.183	.005	54.31	0.46	4.65	0.13
331	2.268	.018	.183	.005	57.61	0.46	4.65	0.13
332	2.393	.018	.183	.005	60.78	0.46	4.65	0.13
333	2.518	.020	.183	.005	63.96	0.51	4.65	0.13
334	2.643	.020	.183	.005	67.13	0.51	4.65	0.13
335	2.768	.020	.183	.005	70.31	0.51	4.65	0.13
336	2.893	.020	.183	.005	73.48	0.51	4.65	0.13
337	3.018	.024	.183	.005	76.66	0.61	4.65	0.13
338	3.143	.024	.183	.005	79.83	0.61	4.65	0.13
339	3.273	.024	.183	.005	83.13	0.61	4.65	0.13
340	3.398	.024	.183	.005	86.31	0.61	4.65	0.13
341	3.523	.024	.183	.005	89.48	0.61	4.65	0.13
342	3.648	.028	.183	.005	92.66	0.71	4.65	0.13
343	3.773	.028	.183	.005	95.83	0.71	4.65	0.13
344	3.898	.028	.183	.005	99.01	0.71	4.65	0.13
345	4.028	.028	.183	.005	102.31	0.71	4.65	0.13
346	4.153	.028	.183	.005	105.49	0.71	4.65	0.13
347	4.278	.030	.183	.005	108.66	0.76	4.65	0.13
348	4.403	.030	.183	.005	111.84	0.76	4.65	0.13
349	4.528	.030	.183	.005	115.01	0.76	4.65	0.13
350	4.653	.030	.183	.005	118.19	0.76	4.65	0.13
351	4.778	.030	.183	.005	121.36	0.76	4.65	0.13
352	4.903	.030	.183	.005	124.54	0.76	4.65	0.13
353	5.028	.037	.183	.005	127.71	0.94	4.65	0.13
354	5.153	.037	.183	.005	130.89	0.94	4.65	0.13
355	5.278	.037	.183	.005	134.06	0.94	4.65	0.13
356	5.403	.037	.183	.005	137.24	0.94	4.65	0.13
357	5.528	.037	.183	.005	140.41	0.94	4.65	0.13
358	5.653	.037	.183	.005	143.59	0.94	4.65	0.13
359	5.778	.037	.183	.005	146.76	0.94	4.65	0.13
360	5.903	.037	.183	.005	149.94	0.94	4.65	0.13
361	6.028	.037	.183	.005	153.11	0.94	4.65	0.13
362	6.278	.040	.183	.005	159.46	1.02	4.65	0.13
363	6.528	.040	.183	.005	165.81	1.02	4.65	0.13
364	6.778	.040	.183	.005	172.16	1.02	4.65	0.13
365	7.028	.040	.183	.005	178.51	1.02	4.65	0.13
366	7.278	.045	.183	.005	184.86	1.14	4.65	0.13
367	7.528	.045	.183	.005	191.21	1.14	4.65	0.13
368	7.778	.045	.183	.005	197.56	1.14	4.65	0.13
369	8.028	.045	.183	.005	203.91	1.14	4.65	0.13
370	8.278	.050	.183	.005	210.26	1.27	4.65	0.13
371	8.528	.050	.183	.005	216.61	1.27	4.65	0.13
372	8.778	.050	.183	.005	222.96	1.27	4.65	0.13
373	9.028	.050	.183	.005	229.31	1.27	4.65	0.13
374	9.278	.055	.183	.005	235.66	1.40	4.65	0.13
375	9.528	.055	.183	.005	242.01	1.40	4.65	0.13
376	9.778	.055	.183	.005	248.36	1.40	4.65	0.13
377	10.028	.055	.183	.005	254.71	1.40	4.65	0.13
378	10.528	.060	.183	.005	267.41	1.52	4.65	0.13
379	11.028	.060	.183	.005	280.11	1.52	4.65	0.13
380	11.528	.065	.183	.005	292.81	1.65	4.65	0.13
381	12.028	.065	.183	.005	305.51	1.65	4.65	0.13
382	13.028	.065	.183	.005	330.91	1.65	4.65	0.13
383	14.028	.070	.183	.005	356.31	1.78	4.65	0.13
384	15.028	.070	.183	.005	381.71	1.78	4.65	0.13
385	16.008	.075	.183	.005	406.60	1.91	4.65	0.13
386	17.008	.080	.183	.005	432.01	2.03	4.65	0.13
387	18.008	.085	.183	.005	457.40	2.16	4.65	0.13
388	19.006	.090	.183	.005	482.75	2.29	4.65	0.13
389	20.006	.095	.183	.005	508.15	2.41	4.65	0.13
390	21.006	.095	.183	.005	533.55	2.41	4.65	0.13
391	22.006	.100	.183	.005	558.95	2.54	4.65	0.13
392	22.993	.105	.183	.005	584.02	2.67	4.65	0.13
393	23.993	.110	.183	.005	609.42	2.79	4.65	0.13
394	24.993	.115	.183	.005	634.82	2.92	4.65	0.13
395	25.993	.120	.183	.005	660.22	3.05	4.65	0.13

Imperial Solid Back-up Sizes

Contoured back-ups are usually made of rubber and mimic the shape of an o’ring on one side to minimises distortion of the o’ring while under pressure.

Available in NBR90 and FKM90 (Viton)

1/16″ Solid Back-up

Includes MS27595
Ht= .050″ ±.002 (1.27mm ±0.05)

Size Reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
004	.080	.001	.055	.001	2.03	0.03	1.40	0.03
005	.111	.001	.055	.001	2.82	0.03	1.40	0.03
006	.125	.001	.055	.001	3.18	0.03	1.40	0.03
007	.156	.001	.055	.001	3.96	0.03	1.40	0.03
008	.187	.001	.055	.001	4.75	0.03	1.40	0.03
009	.219	.001	.055	.001	5.56	0.03	1.40	0.03
010	.250	.001	.055	.001	6.35	0.03	1.40	0.03
011	.312	.001	.055	.001	7.92	0.03	1.40	0.03
012	.375	.001	.055	.001	9.53	0.03	1.40	0.03
013	.440	.001	.055	.001	11.18	0.03	1.40	0.03
014	.503	.001	.055	.001	12.78	0.03	1.40	0.03
015	.565	.001	.055	.001	14.35	0.03	1.40	0.03
016	.628	.001	.055	.001	15.95	0.03	1.40	0.03
017	.690	.001	.055	.001	17.53	0.03	1.40	0.03
018	.753	.001	.055	.001	19.13	0.03	1.40	0.03
019	.815	.001	.055	.001	20.70	0.03	1.40	0.03
020	.881	.001	.055	.001	22.38	0.03	1.40	0.03
021	.943	.002	.055	.001	23.95	0.05	1.40	0.03
022	1.006	.002	.055	.001	25.55	0.05	1.40	0.03
023	1.068	.002	.055	.001	27.13	0.05	1.40	0.03
024	1.131	.002	.055	.001	28.73	0.05	1.40	0.03
025	1.193	.002	.055	.001	30.30	0.05	1.40	0.03
026	1.256	.002	.055	.001	31.90	0.05	1.40	0.03
027	1.318	.002	.055	.001	33.48	0.05	1.40	0.03
028	1.381	.002	.055	.001	35.08	0.05	1.40	0.03
029	1.506	.002	.055	.001	38.25	0.05	1.40	0.03
030	1.631	.002	.055	.001	41.43	0.05	1.40	0.03
031	1.756	.002	.055	.001	44.60	0.05	1.40	0.03
032	1.881	.002	.055	.001	47.78	0.05	1.40	0.03
033	2.086	.002	.055	.001	52.98	0.05	1.40	0.03
034	2.131	.002	.055	.001	54.13	0.05	1.40	0.03
035	2.256	.002	.055	.001	57.30	0.05	1.40	0.03
036	2.381	.002	.055	.001	60.48	0.05	1.40	0.03
037	2.506	.002	.055	.001	63.65	0.05	1.40	0.03
038	2.631	.002	.055	.001	66.83	0.05	1.40	0.03
039	2.756	.002	.055	.001	70.00	0.05	1.40	0.03
040	2.881	.002	.055	.001	73.18	0.05	1.40	0.03
041	3.006	.002	.055	.001	76.35	0.05	1.40	0.03
042	2.256	.002	.055	.001	57.30	0.05	1.40	0.03
043	3.506	.002	.055	.001	89.05	0.05	1.40	0.03
044	3.756	.002	.055	.001	95.40	0.05	1.40	0.03
045	4.006	.002	.055	.001	101.75	0.05	1.40	0.03
046	4.256	.002	.055	.001	108.10	0.05	1.40	0.03
047	4.506	.002	.055	.001	114.45	0.05	1.40	0.03
048	4.756	.002	.055	.001	120.80	0.05	1.40	0.03
049	5.006	.002	.055	.001	127.15	0.05	1.40	0.03
050	5.256	.002	.055	.001	133.50	0.05	1.40	0.03

3/32″ Solid Back-up

Includes MS27595
Ht= .050″ ±.002 (1.27mm ±0.05)

Size Reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
102	.061	.001	.088	.002	1.55	0.03	2.24	0.05
103	.093	.001	.088	.002	2.36	0.03	2.24	0.05
104	.124	.001	.088	.002	3.15	0.03	2.24	0.05
105	.155	.001	.088	.002	3.94	0.03	2.24	0.05
106	.186	.001	.088	.002	4.72	0.03	2.24	0.05
107	.218	.001	.088	.002	5.54	0.03	2.24	0.05
108	.249	.001	.088	.002	6.32	0.03	2.24	0.05
109	.311	.001	.088	.002	7.90	0.03	2.24	0.05
110	.374	.001	.088	.002	9.50	0.03	2.24	0.05
111	.437	.001	.088	.002	11.10	0.03	2.24	0.05
112	.499	.001	.088	.002	12.67	0.03	2.24	0.05
113	.562	.001	.088	.002	14.27	0.03	2.24	0.05
114	.624	.001	.088	.002	15.85	0.03	2.24	0.05
115	.687	.001	.088	.002	17.45	0.03	2.24	0.05
116	.749	.001	.088	.002	19.02	0.03	2.24	0.05
117	.815	.001	.088	.002	20.70	0.03	2.24	0.05
118	.877	.001	.088	.002	22.28	0.03	2.24	0.05
119	.940	.001	.088	.002	23.88	0.03	2.24	0.05
120	1.002	.001	.088	.002	25.45	0.03	2.24	0.05
121	1.065	.002	.088	.002	27.05	0.05	2.24	0.05
122	1.127	.002	.088	.002	28.63	0.05	2.24	0.05
123	1.190	.002	.088	.002	30.23	0.05	2.24	0.05
124	1.252	.002	.088	.002	31.80	0.05	2.24	0.05
125	1.315	.002	.088	.002	33.40	0.05	2.24	0.05
126	1.377	.002	.088	.002	34.98	0.05	2.24	0.05
127	1.440	.002	.088	.002	36.58	0.05	2.24	0.05
128	1.502	.002	.088	.002	38.15	0.05	2.24	0.05
129	1.565	.002	.088	.002	39.75	0.05	2.24	0.05
130	1.629	.002	.088	.002	41.38	0.05	2.24	0.05
131	1.691	.002	.088	.002	42.95	0.05	2.24	0.05
132	1.754	.002	.088	.002	44.55	0.05	2.24	0.05
133	1.816	.002	.088	.002	46.13	0.05	2.24	0.05
134	1.879	.002	.088	.002	47.73	0.05	2.24	0.05
135	1.942	.002	.088	.002	49.33	0.05	2.24	0.05
136	2.004	.002	.088	.002	50.90	0.05	2.24	0.05
137	2.067	.002	.088	.002	52.50	0.05	2.24	0.05
138	2.129	.002	.088	.002	54.08	0.05	2.24	0.05
139	2.192	.002	.088	.002	55.68	0.05	2.24	0.05
140	2.254	.002	.088	.002	57.25	0.05	2.24	0.05
141	2.317	.002	.088	.002	58.85	0.05	2.24	0.05
142	2.379	.002	.088	.002	60.43	0.05	2.24	0.05
143	2.442	.002	.088	.002	62.03	0.05	2.24	0.05
144	2.504	.002	.088	.002	63.60	0.05	2.24	0.05
145	2.567	.002	.088	.002	65.20	0.05	2.24	0.05
146	2.629	.002	.088	.002	66.78	0.05	2.24	0.05
147	2.692	.002	.088	.002	68.38	0.05	2.24	0.05
148	2.754	.002	.088	.002	69.95	0.05	2.24	0.05
149	2.817	.002	.088	.002	71.55	0.05	2.24	0.05
150	2.879	.002	.088	.002	73.13	0.05	2.24	0.05
151	3.004	.002	.088	.002	76.30	0.05	2.24	0.05
152	3.254	.002	.088	.002	82.65	0.05	2.24	0.05
153	3.504	.002	.088	.002	89.00	0.05	2.24	0.05
154	3.754	.002	.088	.002	95.35	0.05	2.24	0.05
155	4.004	.002	.088	.002	101.70	0.05	2.24	0.05
156	4.254	.002	.088	.002	108.05	0.05	2.24	0.05
157	4.504	.002	.088	.002	114.40	0.05	2.24	0.05
158	4.754	.002	.088	.002	120.75	0.05	2.24	0.05
159	5.004	.002	.088	.002	127.10	0.05	2.24	0.05
160	5.254	.002	.088	.002	133.45	0.05	2.24	0.05
161	5.504	.002	.088	.002	139.80	0.05	2.24	0.05
162	5.754	.002	.088	.002	146.15	0.05	2.24	0.05
163	6.004	.002	.088	.002	152.50	0.05	2.24	0.05
164	6.254	.002	.088	.002	158.85	0.05	2.24	0.05
165	6.504	.002	.088	.002	165.20	0.05	2.24	0.05
166	6.754	.002	.088	.002	171.55	0.05	2.24	0.05
167	7.004	.002	.088	.002	177.90	0.05	2.24	0.05
168	7.254	.002	.088	.002	184.25	0.05	2.24	0.05
169	7.504	.002	.088	.002	190.60	0.05	2.24	0.05
170	7.754	.002	.088	.002	196.95	0.05	2.24	0.05
171	8.004	.002	.088	.002	203.30	0.05	2.24	0.05
172	8.254	.002	.088	.002	209.65	0.05	2.24	0.05
173	8.504	.002	.088	.002	216.00	0.05	2.24	0.05
174	8.754	.002	.088	.002	222.35	0.05	2.24	0.05
175	9.004	.002	.088	.002	228.70	0.05	2.24	0.05
176	9.254	.002	.088	.002	235.05	0.05	2.24	0.05
177	9.504	.002	.088	.002	241.40	0.05	2.24	0.05
178	9.754	.002	.088	.002	247.75	0.05	2.24	0.05

1/8″ Solid Back-up

Includes MS27595
Ht= .050″ ±.002 (1.27mm ±0.05)

Size Reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
201	.191	.001	.119	.001	4.85	0.03	3.02	0.03
202	.253	.001	.119	.001	6.43	0.03	3.02	0.03
203	.316	.001	.119	.001	8.03	0.03	3.02	0.03
204	.378	.001	.119	.001	9.60	0.03	3.02	0.03
205	.441	.001	.119	.001	11.20	0.03	3.02	0.03
206	.503	.001	.119	.001	12.78	0.03	3.02	0.03
207	.566	.001	.119	.001	14.38	0.03	3.02	0.03
208	.628	.001	.119	.001	15.95	0.03	3.02	0.03
209	.691	.001	.119	.001	17.55	0.03	3.02	0.03
210	.753	.001	.119	.001	19.13	0.03	3.02	0.03
211	.815	.001	.119	.001	20.70	0.03	3.02	0.03
212	.878	.001	.119	.001	22.30	0.03	3.02	0.03
213	.940	.001	.119	.001	23.88	0.03	3.02	0.03
214	1.003	.002	.119	.001	25.48	0.05	3.02	0.03
215	1.065	.002	.119	.001	27.05	0.05	3.02	0.03
216	1.128	.002	.119	.001	28.65	0.05	3.02	0.03
217	1.190	.002	.119	.001	30.23	0.05	3.02	0.03
218	1.253	.002	.119	.001	31.83	0.05	3.02	0.03
219	1.315	.002	.119	.001	33.40	0.05	3.02	0.03
220	1.378	.002	.119	.001	35.00	0.05	3.02	0.03
221	1.440	.002	.119	.001	36.58	0.05	3.02	0.03
222	1.503	.002	.119	.001	38.18	0.05	3.02	0.03
223	1.629	.002	.119	.001	41.38	0.05	3.02	0.03
224	1.754	.002	.119	.001	44.55	0.05	3.02	0.03
225	1.880	.002	.119	.001	47.75	0.05	3.02	0.03
226	2.005	.002	.119	.001	50.93	0.05	3.02	0.03
227	2.130	.002	.119	.001	54.10	0.05	3.02	0.03
228	2.255	.002	.119	.001	57.28	0.05	3.02	0.03
229	2.380	.002	.119	.001	60.45	0.05	3.02	0.03
230	2.505	.002	.119	.001	63.63	0.05	3.02	0.03
231	2.630	.002	.119	.001	66.80	0.05	3.02	0.03
232	2.755	.002	.119	.001	69.98	0.05	3.02	0.03
233	2.880	.002	.119	.001	73.15	0.05	3.02	0.03
234	3.005	.002	.119	.001	76.33	0.05	3.02	0.03
235	3.130	.002	.119	.001	79.50	0.05	3.02	0.03
236	3.255	.002	.119	.001	82.68	0.05	3.02	0.03
237	3.380	.002	.119	.001	85.85	0.05	3.02	0.03
238	3.505	.002	.119	.001	89.03	0.05	3.02	0.03
239	3.630	.002	.119	.001	92.20	0.05	3.02	0.03
240	3.755	.002	.119	.001	95.38	0.05	3.02	0.03
241	3.880	.002	.119	.001	98.55	0.05	3.02	0.03
242	4.005	.002	.119	.001	101.73	0.05	3.02	0.03
243	4.130	.002	.119	.001	104.90	0.05	3.02	0.03
244	4.255	.002	.119	.001	108.08	0.05	3.02	0.03
245	4.380	.002	.119	.001	111.25	0.05	3.02	0.03
246	4.505	.002	.119	.001	114.43	0.05	3.02	0.03
247	4.630	.002	.119	.001	117.60	0.05	3.02	0.03
248	4.755	.002	.119	.001	120.78	0.05	3.02	0.03
249	4.880	.002	.119	.001	123.95	0.05	3.02	0.03
250	5.005	.002	.119	.001	127.13	0.05	3.02	0.03
251	5.130	.002	.119	.001	130.30	0.05	3.02	0.03
252	5.255	.002	.119	.001	133.48	0.05	3.02	0.03
253	5.380	.002	.119	.001	136.65	0.05	3.02	0.03
254	5.505	.002	.119	.001	139.83	0.05	3.02	0.03
255	5.630	.002	.119	.001	143.00	0.05	3.02	0.03
256	5.755	.002	.119	.001	146.18	0.05	3.02	0.03
257	5.880	.002	.119	.001	149.35	0.05	3.02	0.03
258	6.005	.002	.119	.001	152.53	0.05	3.02	0.03
259	6.255	.002	.119	.001	158.88	0.05	3.02	0.03
260	6.505	.002	.119	.001	165.23	0.05	3.02	0.03
261	6.755	.002	.119	.001	171.58	0.05	3.02	0.03
262	7.005	.002	.119	.001	177.93	0.05	3.02	0.03
263	7.255	.002	.119	.001	184.28	0.05	3.02	0.03
264	7.505	.002	.119	.001	190.63	0.05	3.02	0.03
265	7.755	.002	.119	.001	196.98	0.05	3.02	0.03
266	8.005	.002	.119	.001	203.33	0.05	3.02	0.03
267	8.255	.002	.119	.001	209.68	0.05	3.02	0.03
268	8.505	.002	.119	.001	216.03	0.05	3.02	0.03
269	8.755	.002	.119	.001	222.38	0.05	3.02	0.03
270	9.005	.003	.119	.001	228.73	0.08	3.02	0.03
271	9.255	.003	.119	.001	235.08	0.08	3.02	0.03
272	9.505	.003	.119	.001	241.43	0.08	3.02	0.03
273	9.755	.003	.119	.001	247.78	0.08	3.02	0.03
274	10.005	.003	.119	.001	254.13	0.08	3.02	0.03
275	10.505	.003	.119	.001	266.83	0.08	3.02	0.03
276	11.005	.003	.119	.001	279.53	0.08	3.02	0.03
277	11.505	.003	.119	.001	292.23	0.08	3.02	0.03
278	12.005	.003	.119	.001	304.93	0.08	3.02	0.03
279	13.005	.003	.119	.001	330.33	0.08	3.02	0.03
280	14.005	.003	.119	.001	355.73	0.08	3.02	0.03
281	15.005	.003	.119	.001	381.13	0.08	3.02	0.03
282	16.005	.003	.119	.001	406.53	0.08	3.02	0.03
283	17.005	.003	.119	.001	431.93	0.08	3.02	0.03
284	18.005	.003	.119	.001	457.33	0.08	3.02	0.03

3/16″ Solid Back-up

Includes MS27595
Ht= .073″ ±.002 (1.85mm ±0.05)

Size Reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
309	.435	.002	.185	.001	11.05	0.05	4.70	0.05
310	.497	.002	.185	.001	12.62	0.05	4.70	0.05
311	.560	.002	.185	.001	14.22	0.05	4.70	0.05
312	.622	.002	.185	.001	15.80	0.05	4.70	0.05
313	.685	.002	.185	.001	17.40	0.05	4.70	0.05
314	.747	.002	.185	.001	18.97	0.05	4.70	0.05
315	.810	.002	.185	.001	20.57	0.05	4.70	0.05
316	.872	.002	.185	.001	22.15	0.05	4.70	0.05
317	.935	.002	.185	.001	23.75	0.05	4.70	0.05
318	.997	.002	.185	.001	25.32	0.05	4.70	0.05
319	1.060	.002	.185	.001	26.92	0.05	4.70	0.05
320	1.122	.002	.185	.001	28.50	0.05	4.70	0.05
321	1.185	.002	.185	.001	30.10	0.05	4.70	0.05
322	1.247	.002	.185	.001	31.67	0.05	4.70	0.05
323	1.310	.002	.185	.001	33.27	0.05	4.70	0.05
324	1.372	.002	.185	.001	34.85	0.05	4.70	0.05
325	1.497	.002	.185	.001	38.02	0.05	4.70	0.05
326	1.622	.002	.185	.001	41.20	0.05	4.70	0.05
327	1.748	.002	.185	.001	44.40	0.05	4.70	0.05
328	1.873	.002	.185	.001	47.57	0.05	4.70	0.05
329	1.998	.002	.185	.001	50.75	0.05	4.70	0.05
330	2.123	.002	.185	.001	53.92	0.05	4.70	0.05
331	2.248	.002	.185	.001	57.10	0.05	4.70	0.05
332	2.373	.002	.185	.001	60.27	0.05	4.70	0.05
333	2.498	.002	.185	.001	63.45	0.05	4.70	0.05
334	2.623	.002	.185	.001	66.62	0.05	4.70	0.05
335	2.748	.002	.185	.001	69.80	0.05	4.70	0.05
336	2.873	.002	.185	.001	72.97	0.05	4.70	0.05
337	2.998	.002	.185	.001	76.15	0.05	4.70	0.05
338	3.123	.002	.185	.001	79.32	0.05	4.70	0.05
339	3.248	.002	.185	.001	82.50	0.05	4.70	0.05
340	3.373	.002	.185	.001	85.67	0.05	4.70	0.05
341	3.498	.002	.185	.001	88.85	0.05	4.70	0.05
342	3.623	.002	.185	.001	92.02	0.05	4.70	0.05
343	3.748	.002	.185	.001	95.20	0.05	4.70	0.05
344	3.873	.002	.185	.001	98.37	0.05	4.70	0.05
345	3.998	.002	.185	.001	101.55	0.05	4.70	0.05
346	4.123	.002	.185	.001	104.72	0.05	4.70	0.05
347	4.248	.002	.185	.001	107.90	0.05	4.70	0.05
348	4.373	.002	.185	.001	111.07	0.05	4.70	0.05
349	4.498	.002	.185	.001	114.25	0.05	4.70	0.05
350	4.623	.002	.185	.001	117.42	0.05	4.70	0.05
351	4.748	.002	.185	.001	120.60	0.05	4.70	0.05
352	4.873	.002	.185	.001	123.77	0.05	4.70	0.05
353	4.998	.002	.185	.001	126.95	0.05	4.70	0.05
354	5.123	.002	.185	.001	130.12	0.05	4.70	0.05
355	5.248	.002	.185	.001	133.30	0.05	4.70	0.05
356	5.373	.002	.185	.001	136.47	0.05	4.70	0.05
357	5.498	.002	.185	.001	139.65	0.05	4.70	0.05
358	5.623	.002	.185	.001	142.82	0.05	4.70	0.05
359	5.748	.002	.185	.001	146.00	0.05	4.70	0.05
360	5.873	.002	.185	.001	149.17	0.05	4.70	0.05
361	5.998	.002	.185	.001	152.35	0.05	4.70	0.05
362	6.248	.002	.185	.001	158.70	0.05	4.70	0.05
363	6.498	.002	.185	.001	165.05	0.05	4.70	0.05
364	6.748	.002	.185	.001	171.40	0.05	4.70	0.05
365	6.998	.002	.185	.001	177.75	0.05	4.70	0.05
366	7.248	.002	.185	.001	184.10	0.05	4.70	0.05
367	7.498	.002	.185	.001	190.45	0.05	4.70	0.05
368	7.748	.002	.185	.001	196.80	0.05	4.70	0.05
369	7.998	.002	.185	.001	203.15	0.05	4.70	0.05
370	8.249	.002	.185	.001	209.52	0.05	4.70	0.05
371	8.499	.002	.185	.001	215.87	0.05	4.70	0.05
372	8.749	.002	.185	.001	222.22	0.05	4.70	0.05
373	8.999	.002	.185	.001	228.57	0.05	4.70	0.05
374	9.249	.003	.185	.001	234.92	0.08	4.70	0.05
375	9.499	.003	.185	.001	241.27	0.08	4.70	0.05
376	9.749	.003	.185	.001	247.62	0.08	4.70	0.05
377	9.999	.003	.185	.001	253.97	0.08	4.70	0.05
378	10.499	.003	.185	.001	266.67	0.08	4.70	0.05
379	11.999	.003	.185	.001	304.77	0.08	4.70	0.05
380	11.499	.003	.185	.001	292.07	0.08	4.70	0.05
381	11.999	.004	.185	.001	304.77	0.08	4.70	0.05
382	12.999	.004	.185	.001	330.17	0.08	4.70	0.05
383	13.999	.004	.185	.001	355.57	0.08	4.70	0.05
384	14.999	.004	.185	.001	380.97	0.08	4.70	0.05
385	15.999	.004	.185	.001	406.37	0.08	4.70	0.05
386	16.999	.004	.185	.001	431.77	0.08	4.70	0.05
387	17.999	.004	.185	.001	457.17	0.08	4.70	0.05
388	18.999	.004	.185	.001	482.57	0.08	4.70	0.05
389	19.999	.004	.185	.001	507.97	0.08	4.70	0.05
390	20.999	.005	.185	.001	533.37	0.10	4.70	0.05
391	21.999	.005	.185	.001	558.77	0.10	4.70	0.05
392	22.999	.005	.185	.001	584.17	0.10	4.70	0.05
393	23.999	.005	.185	.001	609.57	0.10	4.70	0.05
394	24.999	.005	.185	.001	634.97	0.10	4.70	0.05
395	25.999	.005	.185	.001	660.37	0.10	4.70	0.05

1/4″ Solid Back-up

Includes MS27595
Ht= .108″ ±.002 (2.74mm ±0.05)

Size Reference	ID (inch)	±	W (inch)	±	ID (mm)	±	W (mm)	±
425	4.502	.002	.236	.001	114.35	0.05	5.99	0.03
426	4.627	.002	.236	.001	117.53	0.05	5.99	0.03
427	4.752	.002	.236	.001	120.70	0.05	5.99	0.03
428	4.877	.002	.236	.001	123.88	0.05	5.99	0.03
429	5.002	.002	.236	.001	127.05	0.05	5.99	0.03
430	5.127	.002	.236	.001	130.23	0.05	5.99	0.03
431	5.252	.002	.236	.001	133.40	0.05	5.99	0.03
432	5.377	.002	.236	.001	136.58	0.05	5.99	0.03
433	5.502	.002	.236	.001	139.75	0.05	5.99	0.03
434	5.627	.002	.236	.001	142.93	0.05	5.99	0.03
435	5.752	.002	.236	.001	146.10	0.05	5.99	0.03
436	5.877	.002	.236	.001	149.28	0.05	5.99	0.03
437	6.002	.002	.236	.001	152.45	0.05	5.99	0.03
438	6.252	.002	.236	.001	158.80	0.05	5.99	0.03
439	6.502	.002	.236	.001	165.15	0.05	5.99	0.03
440	6.752	.002	.236	.001	171.50	0.05	5.99	0.03
441	7.002	.002	.236	.001	177.85	0.05	5.99	0.03
442	7.252	.002	.236	.001	184.20	0.05	5.99	0.03
443	7.502	.002	.236	.001	190.55	0.05	5.99	0.03
444	7.752	.002	.236	.001	196.90	0.05	5.99	0.03
445	8.002	.002	.236	.001	203.25	0.05	5.99	0.03
446	8.502	.003	.236	.001	215.95	0.08	5.99	0.03
447	9.002	.003	.236	.001	228.65	0.08	5.99	0.03
448	9.502	.003	.236	.001	241.35	0.08	5.99	0.03
449	10.002	.003	.236	.001	254.05	0.08	5.99	0.03
450	10.502	.003	.236	.001	266.75	0.08	5.99	0.03
451	11.002	.004	.236	.001	279.45	0.10	5.99	0.03
452	11.502	.004	.236	.001	292.15	0.10	5.99	0.03
453	12.002	.004	.236	.001	304.85	0.10	5.99	0.03
454	12.502	.004	.236	.001	317.55	0.10	5.99	0.03
455	13.002	.004	.236	.001	330.25	0.10	5.99	0.03
456	13.502	.005	.236	.001	342.95	0.13	5.99	0.03
457	14.002	.005	.236	.001	355.65	0.13	5.99	0.03
458	14.502	.005	.236	.001	368.35	0.13	5.99	0.03
459	15.002	.005	.236	.001	381.05	0.13	5.99	0.03
460	15.502	.005	.236	.001	393.75	0.13	5.99	0.03
461	16.002	.006	.236	.001	406.45	0.15	5.99	0.03
462	16.502	.006	.236	.001	419.15	0.15	5.99	0.03
463	17.002	.006	.236	.001	431.85	0.15	5.99	0.03
464	17.502	.006	.236	.001	444.55	0.15	5.99	0.03
465	18.002	.006	.236	.001	457.25	0.15	5.99	0.03
466	18.502	.007	.236	.001	469.95	0.18	5.99	0.03
467	19.002	.007	.236	.001	482.65	0.18	5.99	0.03
468	19.502	.007	.236	.001	495.35	0.18	5.99	0.03
469	20.002	.007	.236	.001	508.05	0.18	5.99	0.03
470	21.002	.007	.236	.001	533.45	0.18	5.99	0.03
471	22.002	.008	.236	.001	558.85	0.20	5.99	0.03
472	23.002	.008	.236	.001	584.25	0.20	5.99	0.03
473	24.002	.008	.236	.001	609.65	0.20	5.99	0.03
474	25.002	.008	.236	.001	635.05	0.20	5.99	0.03
475	26.002	.008	.236	.001	660.45	0.20	5.99	0.03

Metric Solid Back-up Sizes

JIS B2407 P Series Metric Back-up

Size Reference	ID	±	OD	Ht	±
P3	3.00	±0.30	6.00	1.25	±0.10
P4	4.00	±0.30	7.00	1.25	±0.10
P5	5.00	±0.30	8.00	1.25	±0.10
P6	6.00	±0.30	9.00	1.25	±0.10
P7	7.00	±0.30	10.00	1.25	±0.10
P8	8.00	±0.30	11.00	1.25	±0.10
P9	9.00	±0.30	12.00	1.25	±0.10
P10	10.00	±0.30	13.00	1.25	±0.10
P10A	10.00	±0.30	13.00	1.25	±0.10
P11	11.00	±0.30	15.00	1.25	±0.10
P11.2	11.20	±0.30	15.20	1.25	±0.10
P12	12.00	±0.30	16.00	1.25	±0.10
P12.5	12.50	±0.30	16.50	1.25	±0.10
P14	14.00	±0.30	18.00	1.25	±0.10
P15	15.00	±0.30	19.00	1.25	±0.10
P16	16.00	±0.30	20.00	1.25	±0.10
P18	18.00	±0.30	22.00	1.25	±0.10
P20	20.00	±0.30	24.00	1.25	±0.10
P21	21.00	±0.30	25.00	1.25	±0.10
P22	22.00	±0.30	26.00	1.25	±0.10
P22A	22.00	±0.40	28.00	1.25	±0.10
P22.4	22.40	±0.40	28.40	1.25	±0.10
P24	24.00	±0.40	30.00	1.25	±0.10
P25	25.00	±0.40	31.00	1.25	±0.10
P25.5	25.50	±0.40	31.50	1.25	±0.10
P26	26.00	±0.40	32.00	1.25	±0.10
P28	28.00	±0.40	34.00	1.25	±0.10
P29	29.00	±0.40	35.00	1.25	±0.10
P29.5	29.50	±0.40	35.50	1.25	±0.10
P30	30.00	±0.40	36.00	1.25	±0.10
P31	31.00	±0.40	37.00	1.25	±0.10
P31.5	31.50	±0.40	37.50	1.25	±0.10
P32	32.00	±0.40	38.00	1.25	±0.10
P34	34.00	±0.40	40.00	1.25	±0.10
P35	35.00	±0.40	41.00	1.25	±0.10
P35.5	35.50	±0.40	41.50	1.25	±0.10
P36	36.00	±0.40	42.00	1.25	±0.10
P38	38.00	±0.40	44.00	1.25	±0.10
P40	40.00	±0.40	46.00	1.25	±0.10
P41	41.00	±0.40	47.00	1.25	±0.10
P42	42.00	±0.40	48.00	1.25	±0.10
P44	44.00	±0.40	50.00	1.25	±0.10
P45	45.00	±0.40	51.00	1.25	±0.10
P46	46.00	±0.40	52.00	1.25	±0.10
P48	48.00	±0.40	54.00	1.25	±0.10
P48A	48.00	±0.50	58.00	1.90	±0.13
P49	49.00	±0.40	55.00	1.25	±0.10
P50	50.00	±0.40	56.00	1.25	±0.10
P50A	50.00	±0.50	60.00	1.90	±0.13
P52	52.00	±0.50	62.00	1.90	±0.13
P53	53.00	±0.50	63.00	1.90	±0.13
P55	55.00	±0.50	65.00	1.90	±0.13
P56	56.00	±0.50	66.00	1.90	±0.13
P58	58.00	±0.50	68.00	1.90	±0.13
P60	60.00	±0.50	70.00	1.90	±0.13
P62	62.00	±0.50	72.00	1.90	±0.13
P63	63.00	±0.50	73.00	1.90	±0.13
P65	65.00	±0.50	75.00	1.90	±0.13
P67	67.00	±0.50	77.00	1.90	±0.13
P70	70.00	±0.50	80.00	1.90	±0.13
P71	71.00	±0.50	81.00	1.90	±0.13
P75	75.00	±0.50	85.00	1.90	±0.13
P80	80.00	±0.50	90.00	1.90	±0.13
P85	85.00	±0.50	95.00	1.90	±0.13
P86	86.00	±0.50	96.00	1.90	±0.13
P90	90.00	±0.50	100.00	1.90	±0.13
P95	95.00	±0.50	105.00	1.90	±0.13
P100	100.00	±0.50	110.00	1.90	±0.13
P102	102.00	±0.50	112.00	1.90	±0.13
P105	105.00	±0.50	115.00	1.90	±0.13
P110	110.00	±0.50	120.00	1.90	±0.13
P111	111.00	±0.50	121.00	1.90	±0.13
P112	112.00	±0.50	122.00	1.90	±0.13
P115	115.00	±0.50	125.00	1.90	±0.13
P120	120.00	±0.50	130.00	1.90	±0.13
P125	125.00	±0.50	135.00	1.90	±0.13
P130	130.00	±0.50	140.00	1.90	±0.13
P132	132.00	±0.50	142.00	1.90	±0.13
P135	135.00	±0.50	145.00	1.90	±0.13
P140	140.00	±0.50	150.00	1.90	±0.13
P145	145.00	±0.50	155.00	1.90	±0.13
P150	150.00	±0.50	160.00	1.90	±0.13
P150A	150.00	±0.60	165.00	2.75	±0.15
P155	155.00	±0.60	170.00	2.75	±0.15
P160	160.00	±0.60	175.00	2.75	±0.15
P165	165.00	±0.60	175.00	2.75	±0.15
P170	170.00	±0.60	185.00	2.75	±0.15
P175	175.00	±0.60	190.00	2.75	±0.15
P180	180.00	±0.60	195.00	2.75	±0.15
P185	185.00	±0.60	200.00	2.75	±0.15
P190	190.00	±0.60	205.00	2.75	±0.15
P195	195.00	±0.60	210.00	2.75	±0.15
P200	200.00	±0.60	215.00	2.75	±0.15
P205	205.00	±0.60	220.00	2.75	±0.15
P209	209.00	±0.60	224.00	2.75	±0.15
P210	210.00	±0.60	225.00	2.75	±0.15
P215	215.00	±0.60	230.00	2.75	±0.15
P220	220.00	±0.60	235.00	2.75	±0.15
P225	225.00	±0.60	240.00	2.75	±0.15
P230	230.00	±0.60	245.00	2.75	±0.15
P235	235.00	±0.60	250.00	2.75	±0.15
P240	240.00	±0.60	255.00	2.75	±0.15
P245	245.00	±0.60	260.00	2.75	±0.15
P250	250.00	±0.60	265.00	2.75	±0.15
P255	255.00	±0.60	270.00	2.75	±0.15
P260	260.00	±0.60	275.00	2.75	±0.15
P265	265.00	±0.60	280.00	2.75	±0.15
P270	270.00	±0.60	285.00	2.75	±0.15
P275	275.00	±0.60	290.00	2.75	±0.15
P280	280.00	±0.60	295.00	2.75	±0.15
P285	285.00	±0.60	300.00	2.75	±0.15
P290	290.00	±0.60	305.00	2.75	±0.15
P295	295.00	±0.60	310.00	2.75	±0.15
P300	300.00	±0.60	315.00	2.75	±0.15
P315	315.00	±0.60	330.00	2.75	±0.15
P320	320.00	±0.60	335.00	2.75	±0.15
P335	335.00	±0.60	350.00	2.75	±0.15
P360	360.00	±0.60	375.00	2.75	±0.15
P375	375.00	±0.60	380.00	2.75	±0.15
P385	385.00	±0.60	400.00	2.75	±0.15
P400	400.00	±0.60	415.00	2.75	±0.15

JIS B2407 G Series Metric Back-up

Size Reference	ID	±	OD	Ht	±
G25	25.00	±0.40	30.00	1.25	±0.10
G30	30.00	±0.40	35.00	1.25	±0.10
G35	35.00	±0.40	40.00	1.25	±0.10
G40	40.00	±0.40	45.00	1.25	±0.10
G45	45.00	±0.40	50.00	1.25	±0.10
G50	50.00	±0.40	55.00	1.25	±0.10
G55	55.00	±0.50	60.00	1.25	±0.10
G60	60.00	±0.50	75.00	1.25	±0.10
G65	65.00	±0.50	70.00	1.25	±0.10
G70	70.00	±0.50	75.00	1.25	±0.10
G75	75.00	±0.50	80.00	1.25	±0.10
G80	80.00	±0.50	85.00	1.25	±0.10
G85	85.00	±0.50	90.00	1.25	±0.10
G90	90.00	±0.50	95.00	1.25	±0.10
G95	95.00	±0.50	100.00	1.25	±0.10
G100	100.00	±0.50	105.00	1.25	±0.10
G105	105.00	±0.50	110.00	1.25	±0.10
G110	110.00	±0.50	115.00	1.25	±0.10
G115	115.00	±0.50	120.00	1.25	±0.10
G120	120.00	±0.50	125.00	1.25	±0.10
G125	125.00	±0.50	130.00	1.25	±0.10
G130	130.00	±0.50	135.00	1.25	±0.10
G135	135.00	±0.50	140.00	1.25	±0.10
G140	140.00	±0.50	145.00	1.25	±0.10
G145	145.00	±0.50	150.00	1.25	±0.10
G150	150.00	±0.50	160.00	1.25	±0.10
G155	155.00	±0.50	165.00	1.25	±0.10
G160	160.00	±0.50	170.00	1.25	±0.10
G165	165.00	±0.50	175.00	1.25	±0.10
G170	170.00	±0.50	180.00	1.25	±0.10
G175	175.00	±0.50	185.00	1.25	±0.10
G180	180.00	±0.50	190.00	1.25	±0.10
G185	185.00	±0.50	195.00	1.25	±0.10
G190	190.00	±0.50	200.00	1.25	±0.10
G195	195.00	±0.50	205.00	1.25	±0.10
G200	200.00	±0.60	210.00	1.90	±0.13
G210	210.00	±0.60	220.00	1.90	±0.13
G220	220.00	±0.60	230.00	1.90	±0.13
G230	230.00	±0.60	240.00	1.90	±0.13
G240	240.00	±0.60	250.00	1.90	±0.13
G250	250.00	±0.60	260.00	1.90	±0.13
G260	260.00	±0.60	270.00	1.90	±0.13
G270	270.00	±0.60	280.00	1.90	±0.13
G280	280.00	±0.60	290.00	1.90	±0.13
G290	290.00	±0.60	300.00	1.90	±0.13
G300	300.00	±0.60	310.00	1.90	±0.13

Back-up Rings

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Back-up rings

Imperial Contoured Back-up Sizes

1/16″ Contoured Back-up

3/32″ Contoured Back-up

1/8″ Contoured Back-up

3/16″ Contoured Back-up

3/16″ Contoured Back-up

Imperial Solid Back-up Sizes

1/16″ Solid Back-up

3/32″ Solid Back-up

1/8″ Solid Back-up

3/16″ Solid Back-up

1/4″ Solid Back-up

Metric Solid Back-up Sizes

JIS B2407 P Series Metric Back-up

JIS B2407 G Series Metric Back-up