I've been looking for a consistent, universally accepted tolerance table for thermoplastic elastomers. RMA and ISO3302 pretty much have the rubber industry covered, how about thermoplastic elastomers. The RMA book specifically states, "The information in this chapter is not intended to apply to thermoplastic elastomers." Is there a standard that does?

I've been looking for a consistent, universally accepted tolerance table for thermoplastic elastomers. RMA and ISO3302 pretty much have the rubber industry covered, how about thermoplastic elastomers. The RMA book specifically states, "The information in this chapter is not intended to apply to thermoplastic elastomers." Is there a standard that does?

Mike,

ISO 3302-2:2008. This is what the abstract says.....

Abstract

ISO 3302-2:2008 specifies the following geometrical tolerances for moulded and extruded solid rubber products, including those with metal inserts:

flatness tolerance;
parallelism tolerance;
perpendicularity tolerance;
coaxiality tolerance;
positional tolerance.
The tolerances are primarily intended for use with vulcanized rubber but may also be suitable for products made of thermoplastic rubbers.

Emphasis mine.

Am I close?

Stijloor

You should be looking for ASTM (or ISO) specifications specific to the thermoplastic you are trying to control. When I worked for a maker of spring energized thermoplastic seals we had a number of small mom and pop (and a few large aerospace) o-ring suppliers always requesting cure dates for the seals we supplied.

For those of you who may not know, the cure date is the date raw rubber is vulcanized to form the rubber part. Thermoplastics contain no rubber so they are not vulcanized.