Sealing

O-rings: sizes and glands

Pick a ring from the AS568 table or type a metric size, say how it will work, and get the dimensioned groove: depth, width, squeeze, gland fill and surface finish — with a scale section and warnings for anything out of range.

1. Ring

Inside Ø: 24.99 ±0.25 mm
Cross-section: 3.53 mm
Outside Ø: 32.05 mm

-214 — 0.984 × 0.139 pol · 1/8" (0.139 in / 3,53 mm) · tolerance from the DL Seals catalogue

2. Application

ServiceThe two parts stay still relative to each other. That covers almost every O-ring in a mold.MountingAn annular groove in the face of a plate, with water or oil pushing from inside the ring outwards. It's the dominant arrangement in molds: cooling transfer between plates, hot-runner manifold base.

3. Fine tuning

Squeeze: 21%Recommended range for this section and service: 16% to 26% (target 21%).Target gland fill: 75%It sets the groove width. Elastomer is practically incompressible: the spare volume is what absorbs thermal expansion.

Temperature (°C)Radial space available (mm)The diameter of the blind hole or pocket, or the free distance to the nearest cooling channel. Without it the tool has no way to know whether the groove fits in the part.Diametral clearance (mm)

Depth t

2.79

Width b

4.70

Squeeze

0.741

mm · 21%

Gland fill

74.7%

of the groove

Cross-check against the DL Seals catalogue

Width — here	4.70 mm	gland fill fixed at 74.7%
Width — DL Seals	4.85 +0.20 mm	static gland · 1.37× the cross-section
Depth — DL Seals	2.80 mm	squeeze of 20.7%
Radii — DL Seals	bottom R 0.50 · entry R 0.20 mm
Width with back-up ring	1 ring 5.30 · 2 rings 7.00 mm	the gland has to widen to take the back-up ring
Lead-in chamfer Z	3.00 mm	at 15°, so the ring enters without being scraped by the corner

From the static gland table in the DL Seals — O-rings Standard catalogue (setembro/2025). The difference in width isn't an error on either side: here the width comes from a target gland fill, there from a fixed proportion of the cross-section. The depths — which is what sets the squeeze — agree between the two.

Two plates, face groove, pressure from inside. Pressure comes from inside the ring and pushes it against the OUTER wall of the groove — that wall is what seals. That's why the groove is positioned by the ring's outside diameter.

Gland dimensions

Groove width b	4.70 mm	+0,10 / 0
Groove depth t	2.79 mm	± 0,05
Groove inside Ø	22.65 mm
Groove outside Ø	32.05 mm	the wall that seals
Allowable width	4.15 a 5.85 mm	gland fill from 85% to 60%
Bottom corner radius	0.21 a 0.42 mm	the DXF uses the minimum
Mating face roughness	Ra ≤ 1,6 µm
Groove bottom roughness	Ra ≤ 3,2 µm

The DXF carries the closed section profile on layer RASGO and the centre line on layer EIXO: drop it into a sketch and apply a revolved cut around it. X is the axial direction, Y is the radius, units are millimetres. The corner radius comes out at the minimum value.

The complete AS568 table

AS568 is the dash-number series most catalogues use: nominal inside diameter and cross-section in inches, converted here to millimetres at 25.4 mm/in. The ID tolerance column comes from the DL Seals catalogue; where a dash appears, that catalogue doesn't list the size.

349 of 349 sizes. Type a number to find the ring closest to a diameter.

Dash	ID (mm)	CS (mm)	OD (mm)	ID tol.	ID (in)	CS (in)
-001	0.74	1.02	2.77	±0.10	0.029	0.040
-002	1.07	1.27	3.61	±0.10	0.042	0.050
-003	1.42	1.52	4.47	±0.10	0.056	0.060
-004	1.78	1.78	5.33	±0.13	0.070	0.070
-005	2.57	1.78	6.12	±0.13	0.101	0.070
-006	2.90	1.78	6.45	±0.13	0.114	0.070
-007	3.68	1.78	7.24	±0.13	0.145	0.070
-008	4.47	1.78	8.03	±0.13	0.176	0.070
-009	5.28	1.78	8.84	±0.13	0.208	0.070
-010	6.07	1.78	9.63	±0.13	0.239	0.070
-011	7.65	1.78	11.20	±0.13	0.301	0.070
-012	9.25	1.78	12.80	±0.13	0.364	0.070
-013	10.82	1.78	14.38	±0.13	0.426	0.070
-014	12.42	1.78	15.98	±0.13	0.489	0.070
-015	14.00	1.78	17.55	±0.18	0.551	0.070
-016	15.60	1.78	19.15	±0.23	0.614	0.070
-017	17.17	1.78	20.73	±0.23	0.676	0.070
-018	18.77	1.78	22.33	±0.23	0.739	0.070
-019	20.35	1.78	23.90	±0.23	0.801	0.070
-020	21.95	1.78	25.50	±0.23	0.864	0.070
-021	23.52	1.78	27.08	±0.23	0.926	0.070
-022	25.12	1.78	28.68	±0.25	0.989	0.070
-023	26.70	1.78	30.25	±0.25	1.051	0.070
-024	28.30	1.78	31.85	±0.25	1.114	0.070
-025	29.87	1.78	33.43	±0.28	1.176	0.070
-026	31.47	1.78	35.03	±0.28	1.239	0.070
-027	33.05	1.78	36.60	±0.28	1.301	0.070
-028	34.65	1.78	38.20	±0.33	1.364	0.070
-029	37.82	1.78	41.38	±0.33	1.489	0.070
-030	41.00	1.78	44.55	±0.33	1.614	0.070
-031	44.17	1.78	47.73	±0.38	1.739	0.070
-032	47.35	1.78	50.90	±0.38	1.864	0.070
-033	50.52	1.78	54.08	±0.46	1.989	0.070
-034	53.70	1.78	57.25	±0.46	2.114	0.070
-035	56.87	1.78	60.43	±0.46	2.239	0.070
-036	60.05	1.78	63.60	±0.46	2.364	0.070
-037	63.22	1.78	66.78	±0.46	2.489	0.070
-038	66.40	1.78	69.95	±0.51	2.614	0.070
-039	69.57	1.78	73.13	±0.51	2.739	0.070
-040	72.75	1.78	76.30	±0.51	2.864	0.070
-041	75.92	1.78	79.48	±0.61	2.989	0.070
-042	82.27	1.78	85.83	±0.61	3.239	0.070
-043	88.62	1.78	92.18	±0.61	3.489	0.070
-044	94.97	1.78	98.53	±0.69	3.739	0.070
-045	101.32	1.78	104.88	±0.69	3.989	0.070
-046	107.67	1.78	111.23	±0.76	4.239	0.070
-047	114.02	1.78	117.58	±0.76	4.489	0.070
-048	120.37	1.78	123.93	±0.76	4.739	0.070
-049	126.72	1.78	130.28	±0.94	4.989	0.070
-050	133.07	1.78	136.63	±0.94	5.239	0.070
-102	1.24	2.62	6.48	±0.13	0.049	0.103
-103	2.06	2.62	7.29	±0.13	0.081	0.103
-104	2.84	2.62	8.08	±0.13	0.112	0.103
-105	3.63	2.62	8.86	±0.13	0.143	0.103
-106	4.42	2.62	9.65	±0.13	0.174	0.103
-107	5.23	2.62	10.46	±0.13	0.206	0.103
-108	6.02	2.62	11.25	±0.13	0.237	0.103
-109	7.59	2.62	12.83	±0.13	0.299	0.103
-110	9.19	2.62	14.43	±0.13	0.362	0.103
-111	10.77	2.62	16.00	±0.13	0.424	0.103
-112	12.37	2.62	17.60	±0.13	0.487	0.103
-113	13.94	2.62	19.18	±0.18	0.549	0.103
-114	15.54	2.62	20.78	±0.23	0.612	0.103
-115	17.12	2.62	22.35	±0.23	0.674	0.103
-116	18.72	2.62	23.95	±0.23	0.737	0.103
-117	20.29	2.62	25.53	±0.25	0.799	0.103
-118	21.89	2.62	27.13	±0.25	0.862	0.103
-119	23.47	2.62	28.70	±0.25	0.924	0.103
-120	25.07	2.62	30.30	±0.25	0.987	0.103
-121	26.64	2.62	31.88	±0.25	1.049	0.103
-122	28.24	2.62	33.48	±0.25	1.112	0.103
-123	29.82	2.62	35.05	±0.30	1.174	0.103
-124	31.42	2.62	36.65	±0.30	1.237	0.103
-125	32.99	2.62	38.23	±0.30	1.299	0.103
-126	34.59	2.62	39.83	±0.30	1.362	0.103
-127	36.17	2.62	41.40	±0.30	1.424	0.103
-128	37.77	2.62	43.00	±0.30	1.487	0.103
-129	39.34	2.62	44.58	±0.38	1.549	0.103
-130	40.94	2.62	46.18	±0.38	1.612	0.103
-131	42.52	2.62	47.75	±0.38	1.674	0.103
-132	44.12	2.62	49.35	±0.38	1.737	0.103
-133	45.69	2.62	50.93	±0.38	1.799	0.103
-134	47.29	2.62	52.53	±0.38	1.862	0.103
-135	48.90	2.62	54.13	±0.43	1.925	0.103
-136	50.47	2.62	55.70	±0.43	1.987	0.103
-137	52.07	2.62	57.30	±0.43	2.050	0.103
-138	53.64	2.62	58.88	±0.43	2.112	0.103
-139	55.25	2.62	60.48	±0.43	2.175	0.103
-140	56.82	2.62	62.05	±0.43	2.237	0.103
-141	58.42	2.62	63.65	±0.51	2.300	0.103
-142	59.99	2.62	65.23	±0.51	2.362	0.103
-143	61.60	2.62	66.83	±0.51	2.425	0.103
-144	63.17	2.62	68.40	±0.51	2.487	0.103
-145	64.77	2.62	70.00	±0.51	2.550	0.103
-146	66.34	2.62	71.58	±0.51	2.612	0.103
-147	67.95	2.62	73.18	±0.56	2.675	0.103
-148	69.52	2.62	74.75	±0.56	2.737	0.103
-149	71.12	2.62	76.35	±0.56	2.800	0.103
-150	72.69	2.62	77.93	±0.56	2.862	0.103
-151	75.87	2.62	81.10	±0.61	2.987	0.103
-152	82.22	2.62	87.45	±0.61	3.237	0.103
-153	88.57	2.62	93.80	±0.61	3.487	0.103
-154	94.92	2.62	100.15	±0.71	3.737	0.103
-155	101.27	2.62	106.50	±0.71	3.987	0.103
-156	107.62	2.62	112.85	±0.76	4.237	0.103
-157	113.97	2.62	119.20	±0.76	4.487	0.103
-158	120.32	2.62	125.55	±0.76	4.737	0.103
-159	126.67	2.62	131.90	±0.89	4.987	0.103
-160	133.02	2.62	138.25	±0.89	5.237	0.103
-161	139.37	2.62	144.60	±0.89	5.487	0.103
-162	145.72	2.62	150.95	±0.89	5.737	0.103
-163	152.07	2.62	157.30	±0.89	5.987	0.103
-164	158.42	2.62	163.65	±1.02	6.237	0.103
-165	164.77	2.62	170.00	±1.02	6.487	0.103
-166	171.12	2.62	176.35	±1.02	6.737	0.103
-167	177.47	2.62	182.70	±1.02	6.987	0.103
-168	183.82	2.62	189.05	±1.14	7.237	0.103
-169	190.17	2.62	195.40	±1.14	7.487	0.103
-170	196.52	2.62	201.75	±1.14	7.737	0.103
-171	202.87	2.62	208.10	±1.14	7.987	0.103
-172	209.22	2.62	214.45	±1.27	8.237	0.103
-173	215.57	2.62	220.80	±1.27	8.487	0.103
-174	221.92	2.62	227.15	±1.27	8.737	0.103
-175	228.27	2.62	233.50	±1.27	8.987	0.103
-176	234.62	2.62	239.85	±1.40	9.237	0.103
-177	240.97	2.62	246.20	±1.40	9.487	0.103
-178	247.32	2.62	252.55	±1.40	9.737	0.103
-201	4.34	3.53	11.40	±0.13	0.171	0.139
-202	5.94	3.53	13.00	±0.13	0.234	0.139
-203	7.52	3.53	14.58	±0.13	0.296	0.139
-204	9.12	3.53	16.18	±0.13	0.359	0.139
-205	10.69	3.53	17.75	±0.13	0.421	0.139
-206	12.29	3.53	19.35	±0.13	0.484	0.139
-207	13.87	3.53	20.93	±0.18	0.546	0.139
-208	15.47	3.53	22.53	±0.23	0.609	0.139
-209	17.04	3.53	24.10	±0.23	0.671	0.139
-210	18.64	3.53	25.70	±0.25	0.734	0.139
-211	20.22	3.53	27.28	±0.25	0.796	0.139
-212	21.82	3.53	28.88	±0.25	0.859	0.139
-213	23.39	3.53	30.45	±0.25	0.921	0.139
-214	24.99	3.53	32.05	±0.25	0.984	0.139
-215	26.57	3.53	33.63	±0.25	1.046	0.139
-216	28.17	3.53	35.23	±0.30	1.109	0.139
-217	29.74	3.53	36.80	±0.30	1.171	0.139
-218	31.34	3.53	38.40	±0.30	1.234	0.139
-219	32.92	3.53	39.98	±0.30	1.296	0.139
-220	34.52	3.53	41.58	±0.30	1.359	0.139
-221	36.09	3.53	43.15	±0.30	1.421	0.139
-222	37.69	3.53	44.75	±0.38	1.484	0.139
-223	40.87	3.53	47.93	±0.38	1.609	0.139
-224	44.04	3.53	51.10	±0.38	1.734	0.139
-225	47.22	3.53	54.28	±0.46	1.859	0.139
-226	50.39	3.53	57.45	±0.46	1.984	0.139
-227	53.57	3.53	60.63	±0.46	2.109	0.139
-228	56.74	3.53	63.80	±0.51	2.234	0.139
-229	59.92	3.53	66.98	±0.51	2.359	0.139
-230	63.09	3.53	70.15	±0.51	2.484	0.139
-231	66.27	3.53	73.33	±0.51	2.609	0.139
-232	69.44	3.53	76.50	±0.61	2.734	0.139
-233	72.62	3.53	79.68	±0.61	2.859	0.139
-234	75.79	3.53	82.85	±0.61	2.984	0.139
-235	78.97	3.53	86.03	±0.61	3.109	0.139
-236	82.14	3.53	89.20	±0.61	3.234	0.139
-237	85.32	3.53	92.38	±0.61	3.359	0.139
-238	88.49	3.53	95.55	±0.61	3.484	0.139
-239	91.67	3.53	98.73	±0.71	3.609	0.139
-240	94.84	3.53	101.90	±0.71	3.734	0.139
-241	98.02	3.53	105.08	±0.71	3.859	0.139
-242	101.19	3.53	108.25	±0.71	3.984	0.139
-243	104.37	3.53	111.43	±0.71	4.109	0.139
-244	107.54	3.53	114.60	±0.76	4.234	0.139
-245	110.72	3.53	117.78	±0.76	4.359	0.139
-246	113.89	3.53	120.95	±0.76	4.484	0.139
-247	117.07	3.53	124.13	±0.76	4.609	0.139
-248	120.24	3.53	127.30	±0.76	4.734	0.139
-249	123.42	3.53	130.48	±0.89	4.859	0.139
-250	126.59	3.53	133.65	±0.89	4.984	0.139
-251	129.77	3.53	136.83	±0.89	5.109	0.139
-252	132.94	3.53	140.00	±0.89	5.234	0.139
-253	136.12	3.53	143.18	±0.89	5.359	0.139
-254	139.29	3.53	146.35	±0.89	5.484	0.139
-255	142.47	3.53	149.53	±0.89	5.609	0.139
-256	145.64	3.53	152.70	±0.89	5.734	0.139
-257	148.82	3.53	155.88	±0.89	5.859	0.139
-258	151.99	3.53	159.05	±0.89	5.984	0.139
-259	158.34	3.53	165.40	±1.02	6.234	0.139
-260	164.69	3.53	171.75	±1.02	6.484	0.139
-261	171.04	3.53	178.10	±1.02	6.734	0.139
-262	177.39	3.53	184.45	±1.02	6.984	0.139
-263	183.74	3.53	190.80	±1.14	7.234	0.139
-264	190.09	3.53	197.15	±1.14	7.484	0.139
-265	196.44	3.53	203.50	±1.14	7.734	0.139
-266	202.79	3.53	209.85	±1.14	7.984	0.139
-267	209.14	3.53	216.20	±1.27	8.234	0.139
-268	215.49	3.53	222.55	±1.27	8.484	0.139
-269	221.84	3.53	228.90	±1.27	8.734	0.139
-270	228.19	3.53	235.25	±1.27	8.984	0.139
-271	234.54	3.53	241.60	±1.40	9.234	0.139
-272	240.89	3.53	247.95	±1.40	9.484	0.139
-273	247.24	3.53	254.30	±1.40	9.734	0.139
-274	253.59	3.53	260.65	±1.40	9.984	0.139
-275	266.29	3.53	273.35	±1.40	10.484	0.139
-276	278.99	3.53	286.05	±1.65	10.984	0.139
-277	291.69	3.53	298.75	±1.65	11.484	0.139
-278	304.39	3.53	311.45	±1.65	11.984	0.139
-279	329.79	3.53	336.85	±1.65	12.984	0.139
-280	355.19	3.53	362.25	±1.65	13.984	0.139
-281	380.59	3.53	387.65	±1.65	14.984	0.139
-282	405.26	3.53	412.32	±1.91	15.955	0.139
-283	430.66	3.53	437.72	±2.03	16.955	0.139
-284	456.06	3.53	463.12	—	17.955	0.139
-309	10.46	5.33	21.13	±0.13	0.412	0.210
-310	12.07	5.33	22.73	±0.13	0.475	0.210
-311	13.64	5.33	24.31	±0.18	0.537	0.210
-312	15.24	5.33	25.91	±0.23	0.600	0.210
-313	16.81	5.33	27.48	±0.23	0.662	0.210
-314	18.42	5.33	29.08	±0.25	0.725	0.210
-315	19.99	5.33	30.66	±0.25	0.787	0.210
-316	21.59	5.33	32.26	±0.25	0.850	0.210
-317	23.16	5.33	33.83	±0.25	0.912	0.210
-318	24.77	5.33	35.43	±0.25	0.975	0.210
-319	26.34	5.33	37.01	±0.25	1.037	0.210
-320	27.94	5.33	38.61	±0.30	1.100	0.210
-321	29.51	5.33	40.18	±0.30	1.162	0.210
-322	31.12	5.33	41.78	±0.30	1.225	0.210
-323	32.69	5.33	43.36	±0.30	1.287	0.210
-324	34.29	5.33	44.96	±0.30	1.350	0.210
-325	37.47	5.33	48.13	±0.38	1.475	0.210
-326	40.64	5.33	51.31	±0.38	1.600	0.210
-327	43.82	5.33	54.48	±0.38	1.725	0.210
-328	46.99	5.33	57.66	±0.38	1.850	0.210
-329	50.17	5.33	60.83	±0.46	1.975	0.210
-330	53.34	5.33	64.01	±0.46	2.100	0.210
-331	56.52	5.33	67.18	±0.46	2.225	0.210
-332	59.69	5.33	70.36	±0.46	2.350	0.210
-333	62.87	5.33	73.53	±0.51	2.475	0.210
-334	66.04	5.33	76.71	±0.51	2.600	0.210
-335	69.22	5.33	79.88	±0.51	2.725	0.210
-336	72.39	5.33	83.06	±0.51	2.850	0.210
-337	75.57	5.33	86.23	±0.61	2.975	0.210
-338	78.74	5.33	89.41	±0.61	3.100	0.210
-339	81.92	5.33	92.58	±0.61	3.225	0.210
-340	85.09	5.33	95.76	±0.61	3.350	0.210
-341	88.27	5.33	98.93	±0.61	3.475	0.210
-342	91.44	5.33	102.11	±0.71	3.600	0.210
-343	94.62	5.33	105.28	±0.71	3.725	0.210
-344	97.79	5.33	108.46	±0.71	3.850	0.210
-345	100.97	5.33	111.63	±0.71	3.975	0.210
-346	104.14	5.33	114.81	±0.71	4.100	0.210
-347	107.32	5.33	117.98	±0.76	4.225	0.210
-348	110.49	5.33	121.16	±0.76	4.350	0.210
-349	113.67	5.33	124.33	±0.76	4.475	0.210
-350	116.84	5.33	127.51	±0.76	4.600	0.210
-351	120.02	5.33	130.68	±0.76	4.725	0.210
-352	123.19	5.33	133.86	±0.76	4.850	0.210
-353	126.37	5.33	137.03	±0.94	4.975	0.210
-354	129.54	5.33	140.21	±0.94	5.100	0.210
-355	132.72	5.33	143.38	±0.94	5.225	0.210
-356	135.89	5.33	146.56	±0.94	5.350	0.210
-357	139.07	5.33	149.73	±0.94	5.475	0.210
-358	142.24	5.33	152.91	±0.94	5.600	0.210
-359	145.42	5.33	156.08	±0.94	5.725	0.210
-360	148.59	5.33	159.26	±0.94	5.850	0.210
-361	151.77	5.33	162.43	±0.94	5.975	0.210
-362	158.12	5.33	168.78	±1.02	6.225	0.210
-363	164.47	5.33	175.13	±1.02	6.475	0.210
-364	170.82	5.33	181.48	±1.02	6.725	0.210
-365	177.17	5.33	187.83	±1.02	6.975	0.210
-366	183.52	5.33	194.18	±1.14	7.225	0.210
-367	189.87	5.33	200.53	±1.14	7.475	0.210
-368	196.22	5.33	206.88	±1.14	7.725	0.210
-369	202.57	5.33	213.23	±1.14	7.975	0.210
-370	208.92	5.33	219.58	±1.27	8.225	0.210
-371	215.27	5.33	225.93	±1.27	8.475	0.210
-372	221.62	5.33	232.28	±1.27	8.725	0.210
-373	227.97	5.33	238.63	±1.27	8.975	0.210
-374	234.32	5.33	244.98	±1.40	9.225	0.210
-375	240.67	5.33	251.33	±1.40	9.475	0.210
-376	247.02	5.33	257.68	±1.40	9.725	0.210
-377	253.37	5.33	264.03	±1.40	9.975	0.210
-378	266.07	5.33	276.73	±1.52	10.475	0.210
-379	278.77	5.33	289.43	±1.52	10.975	0.210
-380	291.47	5.33	302.13	±1.65	11.475	0.210
-381	304.17	5.33	314.83	±1.65	11.975	0.210
-382	316.87	5.33	327.53	±1.65	12.475	0.210
-383	329.57	5.33	340.23	±1.78	12.975	0.210
-384	342.27	5.33	352.93	±1.78	13.475	0.210
-385	354.97	5.33	365.63	±1.91	13.975	0.210
-386	380.37	5.33	391.03	±2.03	14.975	0.210
-387	405.26	5.33	415.93	±2.16	15.955	0.210
-388	430.66	5.33	441.33	±2.29	16.955	0.210
-389	456.06	5.33	466.73	±2.41	17.955	0.210
-390	481.46	5.33	492.13	±2.41	18.955	0.210
-391	506.86	5.33	517.53	±2.54	19.955	0.210
-392	532.26	5.33	542.93	±2.67	20.955	0.210
-393	557.66	5.33	568.33	±2.79	21.955	0.210
-394	582.68	5.33	593.34	±2.92	22.940	0.210
-395	633.48	5.33	644.14	—	24.940	0.210
-425	113.67	6.99	127.64	±0.84	4.475	0.275
-426	116.84	6.99	130.81	±0.84	4.600	0.275
-427	120.02	6.99	133.99	±0.84	4.725	0.275
-428	123.19	6.99	137.16	±0.84	4.850	0.275
-429	126.37	6.99	140.34	±0.94	4.975	0.275
-430	129.54	6.99	143.51	±0.94	5.100	0.275
-431	132.72	6.99	146.69	±0.94	5.225	0.275
-432	135.89	6.99	149.86	±0.94	5.350	0.275
-433	139.07	6.99	153.04	±0.94	5.475	0.275
-434	142.24	6.99	156.21	±0.94	5.600	0.275
-435	145.42	6.99	159.39	±0.94	5.725	0.275
-436	148.59	6.99	162.56	±0.94	5.850	0.275
-437	151.77	6.99	165.74	±0.94	5.975	0.275
-438	158.12	6.99	172.09	±1.02	6.225	0.275
-439	164.47	6.99	178.44	±1.02	6.475	0.275
-440	170.82	6.99	184.79	±1.02	6.725	0.275
-441	177.17	6.99	191.14	±1.02	6.975	0.275
-442	183.52	6.99	197.49	±1.14	7.225	0.275
-443	189.87	6.99	203.84	±1.14	7.475	0.275
-444	196.22	6.99	210.19	±1.14	7.725	0.275
-445	202.57	6.99	216.54	±1.14	7.975	0.275
-446	215.27	6.99	229.24	±1.40	8.475	0.275
-447	227.97	6.99	241.94	±1.40	8.975	0.275
-448	240.67	6.99	254.64	±1.40	9.475	0.275
-449	253.37	6.99	267.34	±1.40	9.975	0.275
-450	266.07	6.99	280.04	±1.52	10.475	0.275
-451	278.77	6.99	292.74	±1.52	10.975	0.275
-452	291.47	6.99	305.44	±1.52	11.475	0.275
-453	304.17	6.99	318.14	±1.52	11.975	0.275
-454	316.87	6.99	330.84	±1.52	12.475	0.275
-455	329.57	6.99	343.54	±1.52	12.975	0.275
-456	342.27	6.99	356.24	±1.78	13.475	0.275
-457	354.97	6.99	368.94	±1.78	13.975	0.275
-458	367.67	6.99	381.64	±1.78	14.475	0.275
-459	380.37	6.99	394.34	±1.78	14.975	0.275
-460	405.26	6.99	419.23	±1.78	15.955	0.275
-461	430.66	6.99	444.63	±1.91	16.955	0.275
-462	456.06	6.99	470.03	±1.91	17.955	0.275
-463	481.46	6.99	495.43	±2.03	18.955	0.275
-464	506.86	6.99	520.83	±2.16	19.955	0.275
-465	532.26	6.99	546.23	±2.16	20.955	0.275
-466	557.66	6.99	571.63	±2.16	21.955	0.275
-467	582.68	6.99	596.65	±2.29	22.940	0.275
-468	608.08	6.99	622.05	±2.29	23.940	0.275
-469	633.48	6.99	647.45	±2.41	24.940	0.275
-470	658.88	6.99	672.85	±2.41	25.940	0.275
-471	684.28	6.99	698.25	±2.54	26.940	0.275
-472	709.68	6.99	723.65	±2.67	27.940	0.275
-473	735.08	6.99	749.05	±2.79	28.940	0.275
-474	760.48	6.99	774.45	±2.92	29.940	0.275
-475	785.88	6.99	799.85	±3.05	30.940	0.275

How the gland is calculated

Squeeze

It's how much the ring's cross-section is crushed between the groove bottom and the mating face. Without squeeze there is no initial seal; with too much, the elastomer deforms permanently (compression set) and the ring stops springing back.

The recommended percentage falls as the section grows: a 1.78 mm ring works near 21%, a 7.00 mm one near 12%. The calculator interpolates that curve and lets you override the value.

Gland fill

Elastomer is practically incompressible: it changes shape, not volume. The groove width exists to give the ring somewhere to flow when it's squeezed — and to absorb thermal expansion.

The usual range is 60% to 85% of the groove section area. Above 90% the ring pressurises itself when hot and extrudes through the gap.

Stretch and compression

In a male gland the ring goes in stretched over the groove bottom. Up to 5% in static service (3% in dynamic) — beyond that the section thins, the real squeeze drops below the calculated one, and the ring suffers stress relaxation.

In a female gland the opposite happens: the ring is compressed circumferentially, and going past 3% makes it buckle inside the gland.

Clearance and extrusion

The diametral clearance between the two parts is where pressure pushes the ring out. The higher the pressure and the lower the hardness, the smaller the allowable gap — and past a point only a back-up ring solves it.

A face seal doesn't have this problem: the plates close metal on metal, and that's why it's the first choice in a mold.

Use in injection molds

Cooling circuit

Water between plates, plugs and cooling bushings: static sealing, low pressure, temperature up to around 120 °C. A face groove whenever the geometry allows; a radial groove on the plug when it doesn't.

The common failure point isn't the ring — it's an overfilled groove, or a sharp corner at the bottom that cuts the elastomer during assembly.

Hot runner

At the manifold base and the nozzles, working temperature is over 200 °C. NBR is out of scope: the range belongs to FKM, VMQ or, with aggressive resins, FFKM.

At those temperatures, keep the gland fill at 70% or below: the elastomer's thermal expansion needs somewhere to go, or the ring pressurises itself against the groove.

Where the handbooks disagree

Five manufacturer handbooks were read to build this page. On five points they give different numbers for the same thing — and the honest answer is to show all of them, not to pick one and present it as consensus.

Maximum gland fill

It's the reserve the ring has to swell in the fluid and expand with temperature. Overshoot it and the ring pressurises itself against the groove and extrudes.

Parker60% to 85%, optimum at 75%, with at least 10% void
Trelleborgno more than 85%
Meusburger85% maximum
Apple Rubberup to 90% of the minimum void

Maximum ring stretch

Stretching thins the section and drops the actual squeeze. It's the most common source of a leak in a groove whose dimensions match the table.

Parker5% on the installed inside diameter
Trelleborg2% to 5% dynamic, 2% to 8% static
Meusburger6% when installed; up to 20% momentarily during assembly

Squeeze in face sealing

It sets the groove depth. Four sources, four ranges — and none of them is wrong.

Parkerby section: 19-32% (1.78 mm) down to 21-29% (6.99 mm)
Apple Rubberby section: 19-33% down to 20-27%
Trelleborga single 13% to 36% band, derived from ISO 3601-2
Meusburger15% to 30%, for every section

When a back-up ring is required

Below the threshold the ring extrudes through the gap and tears. Above it, the back-up ring adds cost and widens the groove.

Parkerinvestigate above 103.5 bar (1500 psi)
Trelleborgabove 5 MPa for inside Ø > 50 mm; above 10 MPa for Ø < 50 mm

Section loss caused by stretching

It's what makes the actual squeeze fall below the calculated one. The two formulas agree above 3% and diverge below it.

Parkera 4th-degree polynomial between 0 and 3%; from 3 to 25%, the GM Research curve
Trelleborgquadratic between 0 and 3%; from 3 to 25%, the SAME equation as Parker

And what the handbooks don't answer

Gland fill for a dovetail groove. Parker warns that the geometry limits the void area, but publishes no number. None of the other sources covers it.
Squeeze in a triangular crush groove. No published percentage exists, and it wouldn't make sense: the ring is permanently deformed, not elastically compressed. What does exist is Parker's depth table.
Dimension table for a plain circular pocket. Meusburger acknowledges the geometry and says to apply the same squeeze and fill rules as an annular groove, but publishes no table of its own. The other sources only tabulate glands with two walls.
Squeeze and chamfer for a straight-thread boss seal. The values circulating online were not confirmed in any primary source. And the case isn't calculated at all: the dimensions are standardised (AS5202, AS4395, SAE J1926) and use their own ring series.

Finish, fits and assembly

Dimensions alone don't seal. These are the values that go with the groove, and they come from the DL Seals catalogue (O-rings Standard, September 2025).

Roughness — sliding surface	Rt ≤ 4 µm	Rt is the total profile height, not Ra: the two are not interchangeable
Roughness — static surface	Rt ≤ 16 µm
Hardness of the sliding part	45 to 60 HRC	cast iron, bronze, aluminium and brass won't do: they wear the ring out
Bore	H8
Shaft	f7
Gland	h9
Lead-in chamfer Z	2 to 8 mm depending on the section, at 15°	the tool gives the value for the section you chose

A note on provenance: the catalogue page these roughness values come from talks about a sealing lip, which is rotary-shaft-seal vocabulary and not O-ring — most likely reused text. The fits and the chamfer appear in the catalogue's own O-ring gland drawings and are consistent; the roughness is recorded as a manufacturer recommendation, not as a standard.

About the numbers. The sizing here is parametric, derived from the geometric relationships between section, squeeze and groove volume, within design ranges well established in the sealing literature. It is checked against the catalogue from DL Seals: the depths — which is what sets the squeeze and therefore whether it seals — agree within 0.25 mm across the whole tabulated range, and the comparison appears on screen next to the result. Even so it doesn't replace your supplier's catalogue, which carries the compound's chemical compatibility and the extrusion curves by pressure and hardness.