SAE ARP 1153B:2025-05-02

This document describes a method for determining the specific gravity of tubing, fabricated from polytetrafluoroethylene, after a controlled heating and cooling cycle. The specific gravity obtained by this method is a measure of relative molecular weight of the resin. The measure, termed relative specific gravity (RSG), increases with decreasing molecular weight (refer to Sperati and Starkweather, 1961).