RMA Tolerance Chart
Need Custom Rubber Parts to Specific RMA Tolerances?
American Rubber Corp manufactures custom molded rubber parts to RMA Class A1, A2, A3, and A4 tolerances, and extruded products to RMA Class E1, E2, E3, E4. We work with your ASME Y14.5 GD&T drawings. ISO 9001:2015 + IATF 16949 certified.
Request a Quote
Metric Tolerances (mm)
| Nominal Dimension | A1 | A2 | A3 | A4 | |||||
|---|---|---|---|---|---|---|---|---|---|
| above | up to andincluding | Fixed | Closure | Fixed | Closure | Fixed | Closure | Fixed | Closure |
| 0 | 10 | 0.1 | 0.13 | 0.16 | 0.2 | 0.2 | 0.32 | 0.32 | 0.8 |
| 10 | 16 | 0.13 | 0.16 | 0.2 | 0.25 | 0.25 | 0.4 | 0.4 | 0.9 |
| 16 | 25 | 0.16 | 0.2 | 0.2 | 0.32 | 0.32 | 0.5 | 0.5 | 1 |
| 25 | 40 | 0.2 | 0.25 | 0.32 | 0.4 | 0.4 | 0.63 | 0.63 | 1.12 |
| 40 | 63 | 0.25 | 0.32 | 0.4 | 0.5 | 0.5 | 0.8 | 0.8 | 1.25 |
| 63 | 100 | 0.32 | 0.4 | 0.5 | 0.63 | 0.63 | 1 | 1.1 | 1.4 |
| 100 | 160 | 0.4 | 0.5 | 0.63 | 0.8 | 0.8 | 1.25 | 1.25 | 1.6 |
| 160 & over (Multiply by) | x .004 | x .005 | x .005 | x .008 | x .008 | x .010 |
Inch Tolerances (in)
| Nominal Dimension | A1 | A2 | A3 | A4 | |||||
|---|---|---|---|---|---|---|---|---|---|
| above | up to and including | Fixed | Closure | Fixed | Closure | Fixed | Closure | Fixed | Closure |
| 0 | 0.40 | 0.004 | 0.005 | 0.006 | 0.008 | 0.008 | 0.013 | 0.013 | 0.032 |
| 0.40 | 0.63 | 0.005 | 0.006 | 0.008 | 0.010 | 0.010 | 0.016 | 0.016 | 0.036 |
| 0.63 | 1.00 | 0.006 | 0.006 | 0.010 | 0.013 | 0.013 | 0.020 | 0.020 | 0.040 |
| 1.00 | 1.60 | 0.008 | 0.010 | 0.013 | 0.016 | 0.016 | 0.025 | 0.025 | 0.045 |
| 1.60 | 2.50 | 0.010 | 0.013 | 0.016 | 0.020 | 0.020 | 0.032 | 0.032 | 0.050 |
| 2.50 | 4.00 | 0.013 | 0.016 | 0.020 | 0.025 | 0.025 | 0.040 | 0.040 | 0.056 |
| 4.00 | 6.30 | 0.016 | 0.020 | 0.025 | 0.032 | 0.032 | 0.050 | 0.050 | 0.063 |
| 6.30 & over (Multiply by) | x .004 | x .005 | x .005 | x .008 | x .008 | x .010 |
Table 12. Summary of RMA Drawing Designations Extruded Rubber Products
| RMA Class | Dimensional Tolerance* Table 13 | CutLength Tolerance* Table 16 | SplicedLength Tolerance* Table 16 | MandrelCured* Table 20 |
|---|---|---|---|---|
| 1 | E1 | L1 | S1 | EN1 |
| 2 | E2 | L2 | S2 | EN2 |
| 3 | E3 | L3 | S3 | EN3 |
| - | - | - | - | - |
Table 13. Standard Cross-Sectional Tolerance
| RMA Class | 1 - High Precision | 2 - Precision | 3 - Commercial |
|
|---|---|---|---|---|
| Drawing Designation | E1 | E2 | E3 | |
| Dimensions (in Millimeters) | ||||
| Above | Up to and including | |||
| 0 | 1.5 | +0.15 | +0.25 | +0.4 |
| 1.5 | 2.5 | 0.20 | 0.35 | 0.50 |
| 2.5 | 4 | 0.25 | 0.40 | 0.70 |
| 4 | 6.3 | 0.35 | 0.50 | 0.80 |
| 6.3 | 10 | 0.40 | 0.70 | 1.00 |
| 10 | 16 | 0.50 | 0.80 | 1.30 |
| 16 | 25 | 0.70 | 1.00 | 1.60 |
| 25 | 40 | 0.80 | 1.30 | 2.00 |
| 40 | 63 | 1.00 | 1.60 | 2.50 |
| 63 | 100 | 1.30 | 2.00 | 3.20 |
| RMA Class | 1 - High Precision | 2 - Precision | 3 - Commercial | |
| Drawing Designation | E1 | E2 | E3 | |
| Dimensions (in Inches) | ||||
| Above | Up to and including | |||
| 0 | 0.06 | +0.006 | +0.010 | +0.015 |
| 0.06 | 0.10 | 0.008 | 0.014 | 0.020 |
| 0.10 | 0.16 | 0.010 | 0.016 | 0.027 |
| 0.16 | 0.25 | 0.014 | 0.020 | 0.031 |
| 0.25 | 0.39 | 0.016 | 0.027 | 0.039 |
| 0.39 | 0.63 | 0.020 | 0.031 | 0.051 |
| 0.63 | 0.98 | 0.027 | 0.039 | 0.063 |
| 0.98 | 1.57 | 0.031 | 0.051 | 0.079 |
| 1.57 | 2.48 | 0.039 | 0.063 | 0.098 |
| 2.48 | 3.94 | 0.051 | 0.079 | 0.126 |
Table 16. Cut Length tolerance for unspliced extrusion
| 1 - HighPrecision 2 -Precision 3 - Commercial | ||||
|---|---|---|---|---|
| Drawing Designation. | L1 | L2 | L3 | |
| Length (in Millimeters) | ||||
| Above | Up to and including | |||
| 0 | 40 | +0.7 | +0.04 | +1.6 |
| 40 | 63 | 0.08 | 1.3 | 2.0 |
| 63 | 100 | 1.0 | 1.6 | 2.5 |
| 100 | 160 | 1.3 | 2.0 | 3.2 |
| 160 | 250 | 1.6 | 2.5 | 4.0 |
| 250 | 400 | 2.0 | 3.2 | 5.0 |
| 400 | 630 | 2.5 | 4.0 | 6.3 |
| 630 | 1000 | 3.2 | 5.0 | 10.0 |
| 1000 | 1600 | 4.0 | 6.3 | 12.5 |
| 1600 | 2500 | 5.0 | 10.0 | 16.0 |
| 2500 | 4000 | 6.3 | 12.5 | 20.0 |
| 4000 | 0.16% | 0.32% | 0.50% | |
| Length (in Inches) | ||||
| Above | Up to and including | |||
| 1 | 1.6 | +0.03 | +0.04 | +0.06 |
| 1.6 | 2.5 | 0.03 | 0.05 | 0.08 |
| 2.5 | 4 | 0.04 | 0.06 | 0.10 |
| 4 | 6.3 | 0.05 | 0.08 | 0.13 |
| 6.3 | 10 | 0.06 | 0.10 | 0.16 |
| 10 | 16 | 0.8 | 0.13 | 0.20 |
| 16 | 25 | 0.10 | 0.16 | 0.25 |
| 25 | 40 | 0.13 | 0.20 | 0.40 |
| 40 | 63 | 0.16 | 0.25 | 0.50 |
| 63 | 100 | 0.20 | 0.40 | 0.63 |
| 100 | 160 | 0.25 | 0.50 | 0.80 |
| 160 | 0.16% | 0.32% | 0.50% | |
Table 18. Spliced Length Tolerances
| RMA Class | 1 - High Precision | 2 - Precision | 3 - Commercial | |
|---|---|---|---|---|
| Drawing Designation | S1 | S2 | S3 | |
| Millimeters | ||||
| Above | Up to and including | |||
| 0 | 250 | +302 | +3.2 | +7.1 |
| 250 | 400 | 4.0 | 7.1 | 8.0 |
| 400 | 630 | 5.0 | 8.0 | 9.0 |
| 630 | 1000 | 6.3 | 9.0 | 10.0 |
| 1000 | 1600 | 8.0 | 10.0 | 11.2 |
| 1600 | 2500 | 10.0 | 11.2 | 12.3 |
| 2500 | over | 012.5 | 12.5 | 16.0 |
| Inches | ||||
| Above | Up to and including | |||
| 0 | 10 | +.13 | +.25 | +.28 |
| 10 | 16 | .16 | .28 | .32 |
| 16 | 25 | .20 | .32 | .36 |
| 25 | 40 | .25 | .36 | .40 |
| 40 | 63 | .32 | .40 | .45 |
| 63 | 100 | .40 | .45 | .50 |
| 100 | over | .50 | .50 | .53 |
Table 20. Tolerances on Internal Dimensions of Mandrel-Supported Extrusions
| RMA Class | 1 - High Precision | 2 - Commercial | 3 - Non-Critical | |
|---|---|---|---|---|
| Drawing Designation | EN1 | EN2 | EN3 | |
| Nominal Dimensions (in Millimeters) |
||||
| Above | Up to and including | |||
| 0 | 4 | +0.20 | +0.20 | +0.35 |
| 4 | 6.3 | 0.20 | 0.25 | 0.40 |
| 6.3 | 10 | 0.25 | 0.35 | 0.50 |
| 10 | 16 | 0.35 | 0.40 | 0.70 |
| 16 | 25 | 0.40 | 0.50 | 0.80 |
| 25 | 40 | 0.50 | 0.70 | 1.00 |
| 40 | 63 | 0.70 | 0.80 | 1.30 |
| 63 | 100 | 0.80 | 1.00 | 1.60 |
| 100 | 160 | 1.00 | 1.30 | 2.00 |
| 160 | 0.6% | 0.8% | 1.2% | |
| Nominal Dimensions (in Inches) | ||||
| Above | Up to and including | |||
| 0 | 0.16 | +0.008 | +0.08 | +0.014 |
| 0.16 | 0.25 | 0.008 | 0.010 | 0.016 |
| 0.25 | 0.40 | 0.010 | 0.014 | 0.020 |
| 0.4 | 0.63 | 0.014 | 0.016 | 0.028 |
| 0.63 | 1.00 | 0.016 | 0.020 | 0.032 |
| 1.00 | 1.6 | 0.020 | 0.028 | 0.040 |
| 1.6 | 2.5 | 0.028 | 0.032 | 0.051 |
| 2.5 | 4.00 | 0.032 | 0.040 | 0.063 |
| 4.00 | 6.30 | 0.040 | 0.051 | 0.079 |
| 6.30 | 0.6% | 0.8% | 1.2% | |
Request for Quote
Feel free to get in touch with us for all your rubber component-related needs & for discussions around how can we help you as your preferred rubber component manufacturer.
Need these tolerances held in production?
Send us your dimensions or upload a drawing and get a quote within 24 hours — or call +1 (317) 548-8455. Custom sizes and materials welcome.