plating, anodizing, & finishing Q&As since 1989
What kind of rubber is HS 84?
August 6, 2012
Q. Luckily I have found a placement in an engineering company. On a drawing I have been confronted with the reference "rubber HS 84". Despite researching the internet I cannot find what kind of rubber it is. Can anybody help me?
Placement - Dublin, Ireland
A. Hi Tom
What you have there is a requirement for rubber of a specific hardness. Rubber hardness is usually quoted in Shore units measured with a durometer. 84 Shore is fairly hard.
Depending on the application, you have several other questions to answer about the type of rubber, butyl, nitrile, silicone etc.
The simplest way with any drawing question is to ask the designer who signed the drawing. Avoid asking the buyer - it rarely produces any useful information.
November 20, 2012
Q. I'm having issues with gasket similar to valve cover gasket (plastic) found on engines. The issue I'm having is that the gaskets hardness would vary from time to time and the workers would be able to tell the difference because they use it all the time. I finally got a batch of gaskets that I was able to tell the difference.
My question are:
How do I measure the rubber hardness of the gasket using a durometer tester? Do I melt the gasket into a shape (cube, cylindrical, etc) before measuring it?
How does the gasket vary from batch to batch if everything (Arburg 420C machine) is pre-set already?
- Clovis, California, USA