• Sizes and How to Order

• Tolerances for Custom Molded Parts

The following tables illustrate different levels of tolerance control for all elastomeric parts. However, these standard tables do not take into account specific design concerns such as allowable flash. For assistance, please contact Apple Rubber for specific recommendations.

RMA Designation “A1” High Precision

Drawing designation “A1” is the tightest tolerance classification and indicates a high precision product. Such products require expensive molds, fewer cavities per mold, costly in-process controls and inspection procedures. It is desirable that the exact method of measurement be agreed upon between rubber manufacturer and customer, as errors in measurement may be large in relation to the tolerance.

RMA Designation “A2” Precision

Drawing Designation “A2” tolerances indicate a precision product. Molds must be precision machined and kept in good repair. While measurement methods may be simpler than with Drawing Designation “A1", careful inspection will usually be required.

• Fixed - Dimensions not affected by flash thickness variation.
• Closure - Dimensions affected by flash thickness variation.

Tables

Standard AS568 Size O-Rings
Standard O-Rings Boss Gaskets For Straight Thread Tube Fitting