Technical Resource
O-Ring Tolerance Chart
Standard manufacturing tolerance on inside diameter (ID) and cross-section (CS) for FITCO O-rings, specified per Indian and British Standard practice.
Inside diameter tolerance
ID (mm) vs. tolerance (±mm)
| Inner Diameter Range (mm) | Tolerance |
|---|---|
| 1.80 – 2.79 | ±0.13 |
| 2.80 – 4.86 | ±0.14 |
| 4.87 – 6.69 | ±0.15 |
| 6.70 – 8.75 | ±0.16 |
| 8.76 – 10.59 | ±0.17 |
| 10.60 – 11.79 | ±0.18 |
| 11.80 – 14.99 | ±0.19 |
| 15.00 – 16.99 | ±0.20 |
| 17.00 – 18.99 | ±0.21 |
| 19.00 – 21.19 | ±0.22 |
| 21.20 – 22.39 | ±0.23 |
| 22.40 – 24.99 | ±0.24 |
| 25.00 – 27.99 | ±0.25 |
| 28.00 – 29.99 | ±0.26 |
| 30.00 – 31.49 | ±0.28 |
| 31.50 – 32.49 | ±0.29 |
| 32.50 – 34.49 | ±0.31 |
| 34.50 – 35.49 | ±0.33 |
| 35.50 – 36.49 | ±0.34 |
| 36.50 – 37.49 | ±0.35 |
| 37.50 – 38.69 | ±0.36 |
| 38.70 – 39.99 | ±0.37 |
| 40.00 – 41.19 | ±0.38 |
| 41.20 – 42.49 | ±0.39 |
| 42.50 – 43.69 | ±0.40 |
| 43.70 – 44.99 | ±0.41 |
| 45.00 – 46.19 | ±0.42 |
| 46.20 – 47.49 | ±0.43 |
| 47.50 – 48.69 | ±0.44 |
| 48.70 – 49.99 | ±0.45 |
| 50.00 – 51.49 | ±0.46 |
| 51.50 – 52.99 | ±0.47 |
| 53.00 – 54.49 | ±0.48 |
| 54.50 – 55.99 | ±0.50 |
| 56.00 – 57.99 | ±0.51 |
| 58.00 – 59.99 | ±0.52 |
| 60.00 – 61.49 | ±0.54 |
| 61.50 – 62.99 | ±0.55 |
| 63.00 – 64.99 | ±0.56 |
| 65.00 – 66.99 | ±0.58 |
| 67.00 – 68.99 | ±0.59 |
| 69.00 – 70.99 | ±0.61 |
| 71.00 – 72.99 | ±0.63 |
| 73.00 – 74.99 | ±0.64 |
| 75.00 – 77.49 | ±0.66 |
| 77.50 – 79.99 | ±0.67 |
| 80.00 – 82.49 | ±0.69 |
| 82.50 – 84.99 | ±0.71 |
| 85.00 – 87.49 | ±0.73 |
| 87.50 – 89.99 | ±0.75 |
| 90.00 – 92.49 | ±0.77 |
| 92.50 – 94.99 | ±0.79 |
| 95.00 – 97.49 | ±0.81 |
| 97.50 – 99.99 | ±0.83 |
| 100.00 – 102.90 | ±0.84 |
| 103.00 – 105.90 | ±0.87 |
| 106.00 – 108.90 | ±0.89 |
| 109.00 – 111.90 | ±0.91 |
| 112.00 – 114.90 | ±0.93 |
| 115.00 – 117.90 | ±0.95 |
| 118.00 – 121.90 | ±0.97 |
| 122.00 – 124.90 | ±1.00 |
| 125.00 – 127.90 | ±1.03 |
| 128.00 – 131.90 | ±1.05 |
| 132.00 – 135.90 | ±1.08 |
| 136.00 – 139.90 | ±1.10 |
| 140.00 – 144.90 | ±1.13 |
| 145.00 – 149.90 | ±1.17 |
| 150.00 – 154.90 | ±1.20 |
| 155.00 – 159.90 | ±1.24 |
| 160.00 – 164.90 | ±1.27 |
| 165.00 – 169.90 | ±1.31 |
| 170.00 – 174.90 | ±1.34 |
| 175.00 – 179.90 | ±1.38 |
| 180.00 – 184.90 | ±1.41 |
| 185.00 – 189.90 | ±1.44 |
| 190.00 – 194.90 | ±1.48 |
| 195.00 – 199.90 | ±1.51 |
| 200.00 – 205.90 | ±1.55 |
| 206.00 – 211.90 | ±1.59 |
| 212.00 – 217.90 | ±1.63 |
| 218.00 – 223.90 | ±1.67 |
| 224.00 – 229.90 | ±1.71 |
| 230.00 – 235.90 | ±1.75 |
| 236.00 – 242.90 | ±1.79 |
| 243.00 – 249.90 | ±1.83 |
| 250.00 – 257.90 | ±1.88 |
| 258.00 – 264.90 | ±1.93 |
| 265.00 – 271.90 | ±1.98 |
| 272.00 – 279.90 | ±2.02 |
| 280.00 – 289.90 | ±2.08 |
| 290.00 – 299.90 | ±2.14 |
| 300.00 – 306.90 | ±2.21 |
| 307.00 – 314.90 | ±2.25 |
| 315.00 – 324.90 | ±2.30 |
| 325.00 – 334.90 | ±2.37 |
| 335.00 – 344.90 | ±2.43 |
| 345.00 – 354.90 | ±2.49 |
| 355.00 – 364.90 | ±2.56 |
| 365.00 – 374.90 | ±2.62 |
| 375.00 – 386.90 | ±2.68 |
| 387.00 – 399.90 | ±2.76 |
| 400.00 – 411.90 | ±2.84 |
| 412.00 – 424.90 | ±2.91 |
| 425.00 – 436.90 | ±2.99 |
| 437.00 – 449.90 | ±3.07 |
| 450.00 – 461.90 | ±3.15 |
| 462.00 – 474.90 | ±3.22 |
| 475.00 – 486.90 | ±3.30 |
| 487.00 – 499.90 | ±3.37 |
| 500.00 – 514.90 | ±3.45 |
| 515.00 – 529.90 | ±3.54 |
| 530.00 – 544.90 | ±3.63 |
| 545.00 – 559.90 | ±3.72 |
| 560.00 – 579.90 | ±3.81 |
| 580.00 – 599.90 | ±3.93 |
| 600.00 – 614.90 | ±4.05 |
| 615.00 – 629.90 | ±4.13 |
| 630.00 – 649.90 | ±4.22 |
| 650.00 – 669.90 | ±4.34 |
| 670.00 – 689.90 | ±4.46 |
| 690.00 and above | ±0.65% of ID |
Cross-section tolerance
CS (mm) vs. tolerance (±mm)
| Cross-Section (mm) | Tolerance |
|---|---|
| 2.62 | ±0.08 |
| 3.00 | ±0.09 |
| 4.50 | ±0.10 |
| 5.50 | ±0.13 |
| 7.50 | ±0.15 |
| 8.50 | ±0.18 |
| 10.00 | ±0.20 |