MIL-PRF-25690B, PERFORMANCE SPECIFICATION: PLASTIC, SHEETS, AND FORMED PARTS, MODIFIED ACRYLIC BASE, MONOLITHIC, CRACK PROPAGATION RESISTANT (29 JAN 1993) [SUPERSEDING MIL-P-25690A]

MIL-PRF-25690B, PERFORMANCE SPECIFICATION: PLASTIC, SHEETS, AND FORMED PARTS, MODIFIED ACRYLIC BASE, MONOLITHIC, CRACK PROPAGATION RESISTANT (29 JAN 1993) [SUPERSEDING MIL-P-25690A]., This specification covers the requirements for two classes of transparent monolithic, modified, methyl methacrylate flat stretched sheets that may be formed into parts having superior crack propagation and craze resistance as a result of proper hot stretching (see 6.4.2).