The American Society for Testing and Materials (ASTM), formerly called ASTM International, has established and documented more than 12,000 standards used voluntarily around the world to improve product quality, enhance safety, facilitate trade and facilitate market access. The 80-volume Annual Book of ASTM Standards contains them.
The ASTM is a national organisation that is a member of the ISO. ISO has representatives from all countries, including ASTM. With the global consensus of the experts of the associated national organisations, ISO establishes documents and updates standards of testing materials. Such products are safe, reliable, and of high quality. Since ISO standards are developed and updated to meet the needs of international experts, they are more valid.
For three-point testing, the specimen measured 65mm x 40mm x 5mm; for four-point testing, it measured 127mm x 12.7mm x 3.2mm. Compared to the larger specimens of a four point bending test in dentistry, the samples for ISO testing were easier to fabricate in regular dental flasks. To fabricate and polymerize the ASTM samples, larger flasks were required. The variations in the samples size and protocol did not significantly affect the results.