ASTM International Standard Specification for Crucibles, Ignition, Laboratory, Metal ASTM E785-81(2011)

This specification covers two types of metal ignition crucibles, nickel or platinum, complete with covers, for laboratory use. Two types of crucibles shall be classified according to their capacities: Type I is nickel with capacities of 100 mL and 250 mL and Type II is platinum with capacity of 20 mL. Type I are crucibles and covers which shall be made from 99.4% nickel, spun and hardened and Type II are crucibles and covers which shall be made from 99.9% platinum plus iridium, with the iridium content of not more than 0.4%. The crucibles shall have a standard shape with a flat base to give a firm and stable resting surface. The side wall shall form a sloping and convex surface extending up to the brim. Crucibles shall be of one-piece construction. Covers shall be flat, sunken in the center, and shall have an extension to serve as a handle. The sunken area in the center shall fit inside the crucible.