RMA Handbook

Dimensional tolerances, or part tolerances, are acceptable variations in part size. These differences are caused by slight manufacturing variations and expressed as plus or minus (±) amounts in millimeters (mm) or inches (in). Precision parts such as aerospace components require tighter tolerances with less variation. Other types of components, such as consumer products, may allow for greater part-to-part differences.

The Rubber Handbook, a publication from the Association for Rubber Products Manufacturers (ARPM), provides part tolerances for molded and extruded rubber products. Often, this publication is called the RMA Handbook because the ARPM was originally known as the Rubber Manufacturers Association (RMA) before a name change to the U.S. Tire Manufacturers Association.

VIP Rubber and Plastic uses the contents of the RMA Handbook contents to communicate with our customers in a standardized way. The Handbook contains separate chapters for molded and extruded parts, and each chapter contains numbered tables. These tolerance tables, as they’re known, contain allowable part tolerances. They also drawing designations that indicate the level of precision.

The RMA Handbook isn’t free to download, but VIP Rubber and Plastic can share some of its contents with you as we work together on your project. Because the drawings you send to us need to reference RMA information, you’ll find the most important tolerance tables listed below. If you’ve never worked with rubber products before, please note these tolerances are different than with metal products.

These aren’t the only tables in the RMA Handbook – and there are additional chapters besides molded and extruded rubber products. There are also notes, explanations, and other information that product designers may need to consider, so contact us if you have questions about rubber manufacturing. We work with a variety of rubber materials and all of our products are proudly Made in the USA.