DIN 3771 O-Ring Size Chart

DIN 3771 German / EU metric O-Ring size chart with ID, CS, and OD in millimeters and inches, plus the history of DIN 3771.

DIN 3771 is the German metric O-Ring size system widely referenced on EU and German equipment. Sizes are ID × CS in millimeters; store codes use CS×ID.

OD = ID + 2×CS. Code links open a product search on theoringstore.com.

258 sizes · DIN 3771

1.8 mm cross-section

CS 1.8 mm · 36 sizes

DIN 3771 1.8 mm cross-section size table
Code (CS×ID)	ID (mm)	CS (mm)	OD (mm)	ID (in)	CS (in)	OD (in)
1.80X001.8	1.80 ±0.15	1.80 ±0.08	5.40	0.071 ±.006	0.071 ±.003	0.213
1.80X002	2.00 ±0.15	1.80 ±0.08	5.60	0.079 ±.006	0.071 ±.003	0.221
1.80X002.24	2.24 ±0.15	1.80 ±0.08	5.84	0.088 ±.006	0.071 ±.003	0.230
1.80X002.5	2.50 ±0.15	1.80 ±0.08	6.10	0.098 ±.006	0.071 ±.003	0.240
1.80X002.8	2.80 ±0.15	1.80 ±0.08	6.40	0.110 ±.006	0.071 ±.003	0.252
1.80X003.15	3.15 ±0.15	1.80 ±0.08	6.75	0.124 ±.006	0.071 ±.003	0.266
1.80X003.55	3.55 ±0.15	1.80 ±0.08	7.15	0.140 ±.006	0.071 ±.003	0.282
1.80X003.75	3.75 ±0.15	1.80 ±0.08	7.35	0.148 ±.006	0.071 ±.003	0.290
1.80X004	4.00 ±0.15	1.80 ±0.08	7.60	0.158 ±.006	0.071 ±.003	0.299
1.80X004.5	4.50 ±0.15	1.80 ±0.08	8.10	0.177 ±.006	0.071 ±.003	0.319
1.80X004.87	4.87 ±0.15	1.80 ±0.08	8.47	0.192 ±.006	0.071 ±.003	0.334
1.80X005	5.00 ±0.15	1.80 ±0.08	8.60	0.197 ±.006	0.071 ±.003	0.339
1.80X005.15	5.15 ±0.15	1.80 ±0.08	8.75	0.203 ±.006	0.071 ±.003	0.345
1.80X005.3	5.30 ±0.15	1.80 ±0.08	8.90	0.209 ±.006	0.071 ±.003	0.351
1.80X005.6	5.60 ±0.15	1.80 ±0.08	9.20	0.221 ±.006	0.071 ±.003	0.362
1.80X006	6.00 ±0.15	1.80 ±0.08	9.60	0.236 ±.006	0.071 ±.003	0.378
1.80X006.3	6.30 ±0.15	1.80 ±0.08	9.90	0.248 ±.006	0.071 ±.003	0.390
1.80X006.7	6.70 ±0.15	1.80 ±0.08	10.30	0.264 ±.006	0.071 ±.003	0.406
1.80X006.9	6.90 ±0.15	1.80 ±0.08	10.50	0.272 ±.006	0.071 ±.003	0.414
1.80X007.1	7.10 ±0.15	1.80 ±0.08	10.70	0.280 ±.006	0.071 ±.003	0.421
1.80X007.5	7.50 ±0.15	1.80 ±0.08	11.10	0.295 ±.006	0.071 ±.003	0.437
1.80X008	8.00 ±0.15	1.80 ±0.08	11.60	0.315 ±.006	0.071 ±.003	0.457
1.80X008.5	8.50 ±0.15	1.80 ±0.08	12.10	0.335 ±.006	0.071 ±.003	0.477
1.80X008.75	8.75 ±0.15	1.80 ±0.08	12.35	0.344 ±.006	0.071 ±.003	0.486
1.80X009	9.00 ±0.15	1.80 ±0.08	12.60	0.354 ±.006	0.071 ±.003	0.496
1.80X009.5	9.50 ±0.15	1.80 ±0.08	13.10	0.374 ±.006	0.071 ±.003	0.516
1.80X010	10.00 ±0.15	1.80 ±0.08	13.60	0.394 ±.006	0.071 ±.003	0.536
1.80X010.6	10.60 ±0.20	1.80 ±0.08	14.20	0.417 ±.008	0.071 ±.003	0.559
1.80X011.2	11.20 ±0.20	1.80 ±0.08	14.80	0.441 ±.008	0.071 ±.003	0.583
1.80X011.8	11.80 ±0.20	1.80 ±0.08	15.40	0.465 ±.008	0.071 ±.003	0.607
1.80X012.5	12.50 ±0.20	1.80 ±0.08	16.10	0.492 ±.008	0.071 ±.003	0.634
1.80X013.2	13.20 ±0.20	1.80 ±0.08	16.80	0.520 ±.008	0.071 ±.003	0.662
1.80X014	14.00 ±0.20	1.80 ±0.08	17.60	0.551 ±.008	0.071 ±.003	0.693
1.80X015	15.00 ±0.20	1.80 ±0.08	18.60	0.591 ±.008	0.071 ±.003	0.733
1.80X016	16.00 ±0.20	1.80 ±0.08	19.60	0.630 ±.008	0.071 ±.003	0.772
1.80X017	17.00 ±0.20	1.80 ±0.08	20.60	0.669 ±.008	0.071 ±.003	0.811

2.65 mm cross-section

CS 2.65 mm · 23 sizes

DIN 3771 2.65 mm cross-section size table
Code (CS×ID)	ID (mm)	CS (mm)	OD (mm)	ID (in)	CS (in)	OD (in)
2.65X014	14.00 ±0.20	2.65 ±0.09	19.30	0.551 ±.008	0.104 ±.004	0.759
2.65X015	15.00 ±0.20	2.65 ±0.09	20.30	0.591 ±.008	0.104 ±.004	0.799
2.65X016	16.00 ±0.20	2.65 ±0.09	21.30	0.630 ±.008	0.104 ±.004	0.838
2.65X017	17.00 ±0.20	2.65 ±0.09	22.30	0.669 ±.008	0.104 ±.004	0.877
2.65X018	18.00 ±0.20	2.65 ±0.09	23.30	0.709 ±.008	0.104 ±.004	0.917
2.65X019	19.00 ±0.25	2.65 ±0.09	24.30	0.748 ±.010	0.104 ±.004	0.956
2.65X020	20.00 ±0.25	2.65 ±0.09	25.30	0.787 ±.010	0.104 ±.004	0.995
2.65X021.2	21.20 ±0.25	2.65 ±0.09	26.50	0.835 ±.010	0.104 ±.004	1.043
2.65X022.4	22.40 ±0.25	2.65 ±0.09	27.70	0.882 ±.010	0.104 ±.004	1.090
2.65X023.6	23.60 ±0.25	2.65 ±0.09	28.90	0.929 ±.010	0.104 ±.004	1.137
2.65X025	25.00 ±0.25	2.65 ±0.09	30.30	0.984 ±.010	0.104 ±.004	1.192
2.65X025.8	25.80 ±0.25	2.65 ±0.09	31.10	1.016 ±.010	0.104 ±.004	1.224
2.65X026.5	26.50 ±0.25	2.65 ±0.09	31.80	1.043 ±.010	0.104 ±.004	1.251
2.65X028	28.00 ±0.25	2.65 ±0.09	33.30	1.102 ±.010	0.104 ±.004	1.310
2.65X030	30.00 ±0.25	2.65 ±0.09	35.30	1.181 ±.010	0.104 ±.004	1.389
2.65X031.5	31.50 ±0.35	2.65 ±0.09	36.80	1.240 ±.014	0.104 ±.004	1.448
2.65X032.5	32.50 ±0.35	2.65 ±0.09	37.80	1.280 ±.014	0.104 ±.004	1.488
2.65X033.5	33.50 ±0.35	2.65 ±0.09	38.80	1.319 ±.014	0.104 ±.004	1.527
2.65X034.5	34.50 ±0.35	2.65 ±0.09	39.80	1.358 ±.014	0.104 ±.004	1.566
2.65X035.5	35.50 ±0.35	2.65 ±0.09	40.80	1.398 ±.014	0.104 ±.004	1.606
2.65X036.5	36.50 ±0.35	2.65 ±0.09	41.80	1.437 ±.014	0.104 ±.004	1.645
2.65X037.5	37.50 ±0.35	2.65 ±0.09	42.80	1.476 ±.014	0.104 ±.004	1.684
2.65X038.7	38.70 ±0.35	2.65 ±0.09	44.00	1.524 ±.014	0.104 ±.004	1.732

3.55 mm cross-section

CS 3.55 mm · 76 sizes

DIN 3771 3.55 mm cross-section size table
Code (CS×ID)	ID (mm)	CS (mm)	OD (mm)	ID (in)	CS (in)	OD (in)
3.55X018	18.00 ±0.20	3.55 ±0.10	25.10	0.709 ±.008	0.140 ±.004	0.989
3.55X019	19.00 ±0.25	3.55 ±0.10	26.10	0.748 ±.010	0.140 ±.004	1.028
3.55X020	20.00 ±0.25	3.55 ±0.10	27.10	0.787 ±.010	0.140 ±.004	1.067
3.55X021.2	21.20 ±0.25	3.55 ±0.10	28.30	0.835 ±.010	0.140 ±.004	1.115
3.55X022.4	22.40 ±0.25	3.55 ±0.10	29.50	0.882 ±.010	0.140 ±.004	1.162
3.55X023.6	23.60 ±0.25	3.55 ±0.10	30.70	0.929 ±.010	0.140 ±.004	1.209
3.55X025	25.00 ±0.25	3.55 ±0.10	32.10	0.984 ±.010	0.140 ±.004	1.264
3.55X025.8	25.80 ±0.25	3.55 ±0.10	32.90	1.016 ±.010	0.140 ±.004	1.296
3.55X026.5	26.50 ±0.25	3.55 ±0.10	33.60	1.043 ±.010	0.140 ±.004	1.323
3.55X028	28.00 ±0.25	3.55 ±0.10	35.10	1.102 ±.010	0.140 ±.004	1.382
3.55X030	30.00 ±0.25	3.55 ±0.10	37.10	1.181 ±.010	0.140 ±.004	1.461
3.55X031.5	31.50 ±0.35	3.55 ±0.10	38.60	1.240 ±.014	0.140 ±.004	1.520
3.55X032.5	32.50 ±0.35	3.55 ±0.10	39.60	1.280 ±.014	0.140 ±.004	1.560
3.55X033.5	33.50 ±0.35	3.55 ±0.10	40.60	1.319 ±.014	0.140 ±.004	1.599
3.55X034.5	34.50 ±0.35	3.55 ±0.10	41.60	1.358 ±.014	0.140 ±.004	1.638
3.55X035.5	35.50 ±0.35	3.55 ±0.10	42.60	1.398 ±.014	0.140 ±.004	1.678
3.55X036.5	36.50 ±0.35	3.55 ±0.10	43.60	1.437 ±.014	0.140 ±.004	1.717
3.55X037.5	37.50 ±0.35	3.55 ±0.10	44.60	1.476 ±.014	0.140 ±.004	1.756
3.55X038.7	38.70 ±0.35	3.55 ±0.10	45.80	1.524 ±.014	0.140 ±.004	1.804
3.55X040	40.00 ±0.35	3.55 ±0.10	47.10	1.575 ±.014	0.140 ±.004	1.855
3.55X041.2	41.20 ±0.35	3.55 ±0.10	48.30	1.622 ±.014	0.140 ±.004	1.902
3.55X042.5	42.50 ±0.35	3.55 ±0.10	49.60	1.673 ±.014	0.140 ±.004	1.953
3.55X043.7	43.70 ±0.35	3.55 ±0.10	50.80	1.720 ±.014	0.140 ±.004	2.000
3.55X045	45.00 ±0.35	3.55 ±0.10	52.10	1.772 ±.014	0.140 ±.004	2.052
3.55X046.2	46.20 ±0.35	3.55 ±0.10	53.30	1.819 ±.014	0.140 ±.004	2.099
3.55X047.5	47.50 ±0.35	3.55 ±0.10	54.60	1.870 ±.014	0.140 ±.004	2.150
3.55X048.7	48.70 ±0.35	3.55 ±0.10	55.80	1.917 ±.014	0.140 ±.004	2.197
3.55X050	50.00 ±0.35	3.55 ±0.10	57.10	1.968 ±.014	0.140 ±.004	2.248
3.55X051.5	51.50 ±0.40	3.55 ±0.10	58.60	2.028 ±.016	0.140 ±.004	2.308
3.55X053	53.00 ±0.40	3.55 ±0.10	60.10	2.087 ±.016	0.140 ±.004	2.367
3.55X054.5	54.50 ±0.40	3.55 ±0.10	61.60	2.146 ±.016	0.140 ±.004	2.426
3.55X056	56.00 ±0.40	3.55 ±0.10	63.10	2.205 ±.016	0.140 ±.004	2.485
3.55X058	58.00 ±0.40	3.55 ±0.10	65.10	2.284 ±.016	0.140 ±.004	2.564
3.55X060	60.00 ±0.40	3.55 ±0.10	67.10	2.362 ±.016	0.140 ±.004	2.642
3.55X061.5	61.50 ±0.40	3.55 ±0.10	68.60	2.421 ±.016	0.140 ±.004	2.701
3.55X063	63.00 ±0.40	3.55 ±0.10	70.10	2.480 ±.016	0.140 ±.004	2.760
3.55X065	65.00 ±0.40	3.55 ±0.10	72.10	2.559 ±.016	0.140 ±.004	2.839
3.55X067	67.00 ±0.40	3.55 ±0.10	74.10	2.638 ±.016	0.140 ±.004	2.918
3.55X069	69.00 ±0.40	3.55 ±0.10	76.10	2.716 ±.016	0.140 ±.004	2.997
3.55X071	71.00 ±0.40	3.55 ±0.10	78.10	2.795 ±.016	0.140 ±.004	3.075
3.55X073	73.00 ±0.40	3.55 ±0.10	80.10	2.874 ±.016	0.140 ±.004	3.154
3.55X075	75.00 ±0.40	3.55 ±0.10	82.10	2.953 ±.016	0.140 ±.004	3.233
3.55X077.5	77.50 ±0.40	3.55 ±0.10	84.60	3.051 ±.016	0.140 ±.004	3.331
3.55X080	80.00 ±0.40	3.55 ±0.10	87.10	3.150 ±.016	0.140 ±.004	3.430
3.55X082.5	82.50 ±0.50	3.55 ±0.10	89.60	3.248 ±.020	0.140 ±.004	3.528
3.55X085	85.00 ±0.50	3.55 ±0.10	92.10	3.346 ±.020	0.140 ±.004	3.627
3.55X087.5	87.50 ±0.50	3.55 ±0.10	94.60	3.445 ±.020	0.140 ±.004	3.725
3.55X090	90.00 ±0.50	3.55 ±0.10	97.10	3.543 ±.020	0.140 ±.004	3.823
3.55X092.5	92.50 ±0.50	3.55 ±0.10	99.60	3.642 ±.020	0.140 ±.004	3.922
3.55X095	95.00 ±0.50	3.55 ±0.10	102.10	3.740 ±.020	0.140 ±.004	4.020
3.55X097.5	97.50 ±0.50	3.55 ±0.10	104.60	3.839 ±.020	0.140 ±.004	4.119
3.55X100	100.00 ±0.50	3.55 ±0.10	107.10	3.937 ±.020	0.140 ±.004	4.217
3.55X103	103.00 ±0.50	3.55 ±0.10	110.10	4.055 ±.020	0.140 ±.004	4.335
3.55X106	106.00 ±0.50	3.55 ±0.10	113.10	4.173 ±.020	0.140 ±.004	4.453
3.55X109	109.00 ±0.50	3.55 ±0.10	116.10	4.291 ±.020	0.140 ±.004	4.571
3.55X112	112.00 ±0.50	3.55 ±0.10	119.10	4.409 ±.020	0.140 ±.004	4.689
3.55X115	115.00 ±0.50	3.55 ±0.10	122.10	4.528 ±.020	0.140 ±.004	4.808
3.55X118	118.00 ±0.50	3.55 ±0.10	125.10	4.646 ±.020	0.140 ±.004	4.926
3.55X122	122.00 ±0.70	3.55 ±0.10	129.10	4.803 ±.028	0.140 ±.004	5.083
3.55X125	125.00 ±0.70	3.55 ±0.10	132.10	4.921 ±.028	0.140 ±.004	5.201
3.55X128	128.00 ±0.70	3.55 ±0.10	135.10	5.039 ±.028	0.140 ±.004	5.319
3.55X132	132.00 ±0.70	3.55 ±0.10	139.10	5.197 ±.028	0.140 ±.004	5.477
3.55X136	136.00 ±0.70	3.55 ±0.10	143.10	5.354 ±.028	0.140 ±.004	5.634
3.55X140	140.00 ±0.70	3.55 ±0.10	147.10	5.512 ±.028	0.140 ±.004	5.792
3.55X145	145.00 ±0.70	3.55 ±0.10	152.10	5.709 ±.028	0.140 ±.004	5.989
3.55X150	150.00 ±0.70	3.55 ±0.10	157.10	5.905 ±.028	0.140 ±.004	6.186
3.55X155	155.00 ±0.70	3.55 ±0.10	162.10	6.102 ±.028	0.140 ±.004	6.382
3.55X160	160.00 ±0.70	3.55 ±0.10	167.10	6.299 ±.028	0.140 ±.004	6.579
3.55X165	165.00 ±0.70	3.55 ±0.10	172.10	6.496 ±.028	0.140 ±.004	6.776
3.55X170	170.00 ±0.70	3.55 ±0.10	177.10	6.693 ±.028	0.140 ±.004	6.973
3.55X175	175.00 ±0.70	3.55 ±0.10	182.10	6.890 ±.028	0.140 ±.004	7.170
3.55X180	180.00 ±0.70	3.55 ±0.10	187.10	7.087 ±.028	0.140 ±.004	7.367
3.55X185	185.00 ±0.90	3.55 ±0.10	192.10	7.284 ±.035	0.140 ±.004	7.564
3.55X190	190.00 ±0.90	3.55 ±0.10	197.10	7.480 ±.035	0.140 ±.004	7.760
3.55X195	195.00 ±0.90	3.55 ±0.10	202.10	7.677 ±.035	0.140 ±.004	7.957
3.55X200	200.00 ±0.90	3.55 ±0.10	207.10	7.874 ±.035	0.140 ±.004	8.154

5.3 mm cross-section

CS 5.3 mm · 81 sizes

DIN 3771 5.3 mm cross-section size table
Code (CS×ID)	ID (mm)	CS (mm)	OD (mm)	ID (in)	CS (in)	OD (in)
5.30X040	40.00 ±0.35	5.30 ±0.13	50.60	1.575 ±.014	0.209 ±.005	1.993
5.30X041.2	41.20 ±0.35	5.30 ±0.13	51.80	1.622 ±.014	0.209 ±.005	2.040
5.30X042.5	42.50 ±0.35	5.30 ±0.13	53.10	1.673 ±.014	0.209 ±.005	2.091
5.30X043.7	43.70 ±0.35	5.30 ±0.13	54.30	1.720 ±.014	0.209 ±.005	2.139
5.30X045	45.00 ±0.35	5.30 ±0.13	55.60	1.772 ±.014	0.209 ±.005	2.190
5.30X046.2	46.20 ±0.35	5.30 ±0.13	56.80	1.819 ±.014	0.209 ±.005	2.237
5.30X047.5	47.50 ±0.35	5.30 ±0.13	58.10	1.870 ±.014	0.209 ±.005	2.288
5.30X048.7	48.70 ±0.35	5.30 ±0.13	59.30	1.917 ±.014	0.209 ±.005	2.335
5.30X050	50.00 ±0.35	5.30 ±0.13	60.60	1.968 ±.014	0.209 ±.005	2.386
5.30X051.5	51.50 ±0.40	5.30 ±0.13	62.10	2.028 ±.016	0.209 ±.005	2.446
5.30X053	53.00 ±0.40	5.30 ±0.13	63.60	2.087 ±.016	0.209 ±.005	2.505
5.30X054.5	54.50 ±0.40	5.30 ±0.13	65.10	2.146 ±.016	0.209 ±.005	2.564
5.30X056	56.00 ±0.40	5.30 ±0.13	66.60	2.205 ±.016	0.209 ±.005	2.623
5.30X058	58.00 ±0.40	5.30 ±0.13	68.60	2.284 ±.016	0.209 ±.005	2.702
5.30X060	60.00 ±0.40	5.30 ±0.13	70.60	2.362 ±.016	0.209 ±.005	2.780
5.30X061.5	61.50 ±0.40	5.30 ±0.13	72.10	2.421 ±.016	0.209 ±.005	2.839
5.30X063	63.00 ±0.40	5.30 ±0.13	73.60	2.480 ±.016	0.209 ±.005	2.898
5.30X065	65.00 ±0.40	5.30 ±0.13	75.60	2.559 ±.016	0.209 ±.005	2.977
5.30X067	67.00 ±0.40	5.30 ±0.13	77.60	2.638 ±.016	0.209 ±.005	3.056
5.30X069	69.00 ±0.40	5.30 ±0.13	79.60	2.716 ±.016	0.209 ±.005	3.135
5.30X071	71.00 ±0.40	5.30 ±0.13	81.60	2.795 ±.016	0.209 ±.005	3.213
5.30X073	73.00 ±0.40	5.30 ±0.13	83.60	2.874 ±.016	0.209 ±.005	3.292
5.30X075	75.00 ±0.40	5.30 ±0.13	85.60	2.953 ±.016	0.209 ±.005	3.371
5.30X077.5	77.50 ±0.40	5.30 ±0.13	88.10	3.051 ±.016	0.209 ±.005	3.469
5.30X080	80.00 ±0.40	5.30 ±0.13	90.60	3.150 ±.016	0.209 ±.005	3.568
5.30X082.5	82.50 ±0.50	5.30 ±0.13	93.10	3.248 ±.020	0.209 ±.005	3.666
5.30X085	85.00 ±0.50	5.30 ±0.13	95.60	3.346 ±.020	0.209 ±.005	3.764
5.30X087.5	87.50 ±0.50	5.30 ±0.13	98.10	3.445 ±.020	0.209 ±.005	3.863
5.30X090	90.00 ±0.50	5.30 ±0.13	100.60	3.543 ±.020	0.209 ±.005	3.961
5.30X092.5	92.50 ±0.50	5.30 ±0.13	103.10	3.642 ±.020	0.209 ±.005	4.060
5.30X095	95.00 ±0.50	5.30 ±0.13	105.60	3.740 ±.020	0.209 ±.005	4.158
5.30X097.5	97.50 ±0.50	5.30 ±0.13	108.10	3.839 ±.020	0.209 ±.005	4.257
5.30X100	100.00 ±0.50	5.30 ±0.13	110.60	3.937 ±.020	0.209 ±.005	4.355
5.30X103	103.00 ±0.50	5.30 ±0.13	113.60	4.055 ±.020	0.209 ±.005	4.473
5.30X106	106.00 ±0.50	5.30 ±0.13	116.60	4.173 ±.020	0.209 ±.005	4.591
5.30X109	109.00 ±0.50	5.30 ±0.13	119.60	4.291 ±.020	0.209 ±.005	4.709
5.30X112	112.00 ±0.50	5.30 ±0.13	122.60	4.409 ±.020	0.209 ±.005	4.827
5.30X115	115.00 ±0.50	5.30 ±0.13	125.60	4.528 ±.020	0.209 ±.005	4.946
5.30X118	118.00 ±0.50	5.30 ±0.13	128.60	4.646 ±.020	0.209 ±.005	5.064
5.30X122	122.00 ±0.70	5.30 ±0.13	132.60	4.803 ±.028	0.209 ±.005	5.221
5.30X125	125.00 ±0.70	5.30 ±0.13	135.60	4.921 ±.028	0.209 ±.005	5.339
5.30X128	128.00 ±0.70	5.30 ±0.13	138.60	5.039 ±.028	0.209 ±.005	5.457
5.30X132	132.00 ±0.70	5.30 ±0.13	142.60	5.197 ±.028	0.209 ±.005	5.615
5.30X136	136.00 ±0.70	5.30 ±0.13	146.60	5.354 ±.028	0.209 ±.005	5.772
5.30X140	140.00 ±0.70	5.30 ±0.13	150.60	5.512 ±.028	0.209 ±.005	5.930
5.30X145	145.00 ±0.70	5.30 ±0.13	155.60	5.709 ±.028	0.209 ±.005	6.127
5.30X150	150.00 ±0.70	5.30 ±0.13	160.60	5.905 ±.028	0.209 ±.005	6.324
5.30X155	155.00 ±0.70	5.30 ±0.13	165.60	6.102 ±.028	0.209 ±.005	6.520
5.30X160	160.00 ±0.70	5.30 ±0.13	170.60	6.299 ±.028	0.209 ±.005	6.717
5.30X165	165.00 ±0.70	5.30 ±0.13	175.60	6.496 ±.028	0.209 ±.005	6.914
5.30X170	170.00 ±0.70	5.30 ±0.13	180.60	6.693 ±.028	0.209 ±.005	7.111
5.30X175	175.00 ±0.70	5.30 ±0.13	185.60	6.890 ±.028	0.209 ±.005	7.308
5.30X180	180.00 ±0.70	5.30 ±0.13	190.60	7.087 ±.028	0.209 ±.005	7.505
5.30X185	185.00 ±0.90	5.30 ±0.13	195.60	7.284 ±.035	0.209 ±.005	7.702
5.30X190	190.00 ±0.90	5.30 ±0.13	200.60	7.480 ±.035	0.209 ±.005	7.898
5.30X195	195.00 ±0.90	5.30 ±0.13	205.60	7.677 ±.035	0.209 ±.005	8.095
5.30X200	200.00 ±0.90	5.30 ±0.13	210.60	7.874 ±.035	0.209 ±.005	8.292
5.30X206	206.00 ±0.90	5.30 ±0.13	216.60	8.110 ±.035	0.209 ±.005	8.528
5.30X212	212.00 ±0.90	5.30 ±0.13	222.60	8.347 ±.035	0.209 ±.005	8.764
5.30X218	218.00 ±0.90	5.30 ±0.13	228.60	8.583 ±.035	0.209 ±.005	9.001
5.30X224	224.00 ±0.90	5.30 ±0.13	234.60	8.819 ±.035	0.209 ±.005	9.237
5.30X230	230.00 ±0.90	5.30 ±0.13	240.60	9.055 ±.035	0.209 ±.005	9.473
5.30X236	236.00 ±0.90	5.30 ±0.13	246.60	9.291 ±.035	0.209 ±.005	9.709
5.30X243	243.00 ±0.90	5.30 ±0.13	253.60	9.567 ±.035	0.209 ±.005	9.985
5.30X250	250.00 ±0.90	5.30 ±0.13	260.60	9.842 ±.035	0.209 ±.005	10.260
5.30X258	258.00 ±1.20	5.30 ±0.13	268.60	10.158 ±.047	0.209 ±.005	10.575
5.30X265	265.00 ±1.20	5.30 ±0.13	275.60	10.433 ±.047	0.209 ±.005	10.851
5.30X272	272.00 ±1.20	5.30 ±0.13	282.60	10.709 ±.047	0.209 ±.005	11.127
5.30X280	280.00 ±1.20	5.30 ±0.13	290.60	11.024 ±.047	0.209 ±.005	11.442
5.30X290	290.00 ±1.20	5.30 ±0.13	300.60	11.417 ±.047	0.209 ±.005	11.835
5.30X300	300.00 ±1.20	5.30 ±0.13	310.60	11.811 ±.047	0.209 ±.005	12.229
5.30X307	307.00 ±1.20	5.30 ±0.13	317.60	12.087 ±.047	0.209 ±.005	12.505
5.30X315	315.00 ±1.20	5.30 ±0.13	325.60	12.402 ±.047	0.209 ±.005	12.820
5.30X325	325.00 ±1.20	5.30 ±0.13	335.60	12.795 ±.047	0.209 ±.005	13.213
5.30X335	335.00 ±1.20	5.30 ±0.13	345.60	13.189 ±.047	0.209 ±.005	13.607
5.30X345	345.00 ±1.20	5.30 ±0.13	355.60	13.583 ±.047	0.209 ±.005	14.001
5.30X355	355.00 ±1.20	5.30 ±0.13	365.60	13.976 ±.047	0.209 ±.005	14.394
5.30X365	365.00 ±1.20	5.30 ±0.13	375.60	14.370 ±.047	0.209 ±.005	14.788
5.30X375	375.00 ±1.20	5.30 ±0.13	385.60	14.764 ±.047	0.209 ±.005	15.182
5.30X387	387.00 ±1.20	5.30 ±0.13	397.60	15.236 ±.047	0.209 ±.005	15.654
5.30X400	400.00 ±1.20	5.30 ±0.13	410.60	15.748 ±.047	0.209 ±.005	16.166

7 mm cross-section

CS 7 mm · 42 sizes

DIN 3771 7 mm cross-section size table
Code (CS×ID)	ID (mm)	CS (mm)	OD (mm)	ID (in)	CS (in)	OD (in)
7.00X206	206.00 ±0.90	7.00 ±0.15	220.00	8.110 ±.035	0.276 ±.006	8.662
7.00X212	212.00 ±0.90	7.00 ±0.15	226.00	8.347 ±.035	0.276 ±.006	8.899
7.00X218	218.00 ±0.90	7.00 ±0.15	232.00	8.583 ±.035	0.276 ±.006	9.135
7.00X224	224.00 ±0.90	7.00 ±0.15	238.00	8.819 ±.035	0.276 ±.006	9.371
7.00X230	230.00 ±0.90	7.00 ±0.15	244.00	9.055 ±.035	0.276 ±.006	9.607
7.00X236	236.00 ±0.90	7.00 ±0.15	250.00	9.291 ±.035	0.276 ±.006	9.843
7.00X243	243.00 ±0.90	7.00 ±0.15	257.00	9.567 ±.035	0.276 ±.006	10.119
7.00X250	250.00 ±0.90	7.00 ±0.15	264.00	9.842 ±.035	0.276 ±.006	10.394
7.00X258	258.00 ±1.20	7.00 ±0.15	272.00	10.158 ±.047	0.276 ±.006	10.710
7.00X265	265.00 ±1.20	7.00 ±0.15	279.00	10.433 ±.047	0.276 ±.006	10.985
7.00X272	272.00 ±1.20	7.00 ±0.15	286.00	10.709 ±.047	0.276 ±.006	11.261
7.00X280	280.00 ±1.20	7.00 ±0.15	294.00	11.024 ±.047	0.276 ±.006	11.576
7.00X290	290.00 ±1.20	7.00 ±0.15	304.00	11.417 ±.047	0.276 ±.006	11.969
7.00X300	300.00 ±1.20	7.00 ±0.15	314.00	11.811 ±.047	0.276 ±.006	12.363
7.00X307	307.00 ±1.20	7.00 ±0.15	321.00	12.087 ±.047	0.276 ±.006	12.639
7.00X315	315.00 ±1.20	7.00 ±0.15	329.00	12.402 ±.047	0.276 ±.006	12.954
7.00X325	325.00 ±1.20	7.00 ±0.15	339.00	12.795 ±.047	0.276 ±.006	13.347
7.00X335	335.00 ±1.20	7.00 ±0.15	349.00	13.189 ±.047	0.276 ±.006	13.741
7.00X345	345.00 ±1.20	7.00 ±0.15	359.00	13.583 ±.047	0.276 ±.006	14.135
7.00X355	355.00 ±1.20	7.00 ±0.15	369.00	13.976 ±.047	0.276 ±.006	14.528
7.00X365	365.00 ±1.20	7.00 ±0.15	379.00	14.370 ±.047	0.276 ±.006	14.922
7.00X375	375.00 ±1.20	7.00 ±0.15	389.00	14.764 ±.047	0.276 ±.006	15.316
7.00X387	387.00 ±1.20	7.00 ±0.15	401.00	15.236 ±.047	0.276 ±.006	15.788
7.00X400	400.00 ±1.20	7.00 ±0.15	414.00	15.748 ±.047	0.276 ±.006	16.300
7.00X412	412.00 ±1.20	7.00 ±0.15	426.00	16.221 ±.047	0.276 ±.006	16.773
7.00X425	425.00 ±1.20	7.00 ±0.15	439.00	16.732 ±.047	0.276 ±.006	17.284
7.00X437	437.00 ±1.20	7.00 ±0.15	451.00	17.205 ±.047	0.276 ±.006	17.757
7.00X450	450.00 ±1.20	7.00 ±0.15	464.00	17.716 ±.047	0.276 ±.006	18.268
7.00X462	462.00 ±1.20	7.00 ±0.15	476.00	18.189 ±.047	0.276 ±.006	18.741
7.00X475	475.00 ±1.20	7.00 ±0.15	489.00	18.701 ±.047	0.276 ±.006	19.253
7.00X487	487.00 ±1.20	7.00 ±0.15	501.00	19.173 ±.047	0.276 ±.006	19.725
7.00X500	500.00 ±1.20	7.00 ±0.15	514.00	19.685 ±.047	0.276 ±.006	20.237
7.00X515	515.00 ±1.20	7.00 ±0.15	529.00	20.276 ±.047	0.276 ±.006	20.828
7.00X530	530.00 ±1.20	7.00 ±0.15	544.00	20.866 ±.047	0.276 ±.006	21.418
7.00X545	545.00 ±1.20	7.00 ±0.15	559.00	21.457 ±.047	0.276 ±.006	22.009
7.00X560	560.00 ±1.20	7.00 ±0.15	574.00	22.047 ±.047	0.276 ±.006	22.599
7.00X580	580.00 ±1.20	7.00 ±0.15	594.00	22.835 ±.047	0.276 ±.006	23.387
7.00X600	600.00 ±1.20	7.00 ±0.15	614.00	23.622 ±.047	0.276 ±.006	24.174
7.00X615	615.00 ±1.20	7.00 ±0.15	629.00	24.213 ±.047	0.276 ±.006	24.765
7.00X630	630.00 ±1.20	7.00 ±0.15	644.00	24.803 ±.047	0.276 ±.006	25.355
7.00X650	650.00 ±1.20	7.00 ±0.15	664.00	25.591 ±.047	0.276 ±.006	26.143
7.00X670	670.00 ±1.20	7.00 ±0.15	684.00	26.378 ±.047	0.276 ±.006	26.930

Other size charts

Need	Chart
AS568 dash (0xx-4xx)	AS568 O-Ring Size Chart
Metric / ISO 3601	Metric O-Ring Size Chart
JIS S/P/G/V	JIS B 2401 Size Chart
ORB / 900-series boss	ORB Boss Size Chart
Back-up rings	Backup Ring Size Chart
DIN 3771	DIN 3771 Size Chart
Generic Metric	Generic Metric Size Chart
BS 4518	BS 4518 Size Chart
BS 1806	BS 1806 Size Chart
NF T 47-501	NF T 47-501 Size Chart
SMS 1586	SMS 1586 Size Chart
X-Ring	X-Ring Size Chart
Square Ring	Square Ring Size Chart
Parker 500	Parker 500 Size Chart
ISO 6149 ports	ISO 6149 Size Chart
Search across standards	Master O-Ring Size Chart

History and explanation of the DIN 3771 standard

What DIN 3771 is

DIN 3771 defined preferred metric O-Ring sizes for German industry. On prints you usually see millimeter ID and cross-section rather than an AS568 dash.

Why it still shows up

Even after ISO 3601 became the international reference, many European catalogs, glands, and spare-parts lists still say DIN. The geometry often overlaps ISO/metric practice, but the name on the print is what the buyer searches.

DIN and ISO 3601

Early ISO 3601-1 drew heavily on European (DIN-style) metric sizes. Later ISO revisions also folded in AS568-aligned Class A sizes. Practical rule:

Print says DIN / metric mm → start here or on the Metric / ISO chart
Print says -214 → AS568 chart

What it does not tell you

Size only. Compound and groove still come from materials pages, compatibility, and gland design.

DIN 3771 O-Ring Size Chart

1.8 mm cross-section

2.65 mm cross-section

3.55 mm cross-section

5.3 mm cross-section

7 mm cross-section

Other size charts

History and explanation of the DIN 3771 standard

What DIN 3771 is

Why it still shows up

DIN and ISO 3601

What it does not tell you

Handbook

The O-Ring Store

Get In Touch

1.8 mm cross-section

2.65 mm cross-section

3.55 mm cross-section

5.3 mm cross-section

7 mm cross-section

Other size charts

Related

History and explanation of the DIN 3771 standard

What DIN 3771 is

Why it still shows up

DIN and ISO 3601

What it does not tell you

Handbook

The O-Ring Store

Get In Touch