Have you ever had questions about how we break down our part numbers? While we offer a brief explanation on our website, there is something worth mentioning here: “durometer” is the term we use to measure hardness. Based on a number of tests and applications, we’ve determined that 87 in a Shore A scale is the optimal durometer for many of our recessed rubber bumpers. And what exactly does that mean? Shore durometer (named after American metallurgist Albert F. Shore) is a way of measuring the hardness of polymers, elastomers, and rubber; harder materials yield higher numbers while softer materials possess lower numbers. There are 12 Shore scales and “A” happens to be the most common scale.
So when you receive an order with “TPR87” in the line, you’re getting a piece made of Thermo Plastic Rubber in 87 Shore A durometer; this particular hardness is often compared to a skateboard wheel or shoe sole. Depending on your application, you might need rubber feet that are softer for better grip which is why Budwig offers custom durometers of 73 and 64 in Shore A.
Need an ultra-hard bumper? We can injection-mold our parts in a Shore D scale as well. Thus, a line including “PP65D” would mean a PolyPropylene piece in a 65 durometer on the Shore D scale. We offer limited quantities of free samples within the continental United States so please get in touch today to find the best rubber feet for your next project.