MIL-C-26074

Requirement	Callout
350-400°F for 3+ hr embrittlement only for steel > Rockwell C40 no treatment for other material	Class 1
550 °F for 2+ hr 650 °F for 1-1.5 hr hardness must be > 800 HK100	Class 2
360 to 390°F for 1-1.5 hr for non heat-treatable aluminum	Class 3
240 to 260°F for 1-1.5 hr for heat-treatable aluminum	Class 4
1.0 mil minimum thickness	Grade A
0.5 mil minimum thickness	Grade B
1.5 mil minimum thickness	Grade C

AMS2404

Requirement	Callout
350-400°F for 3+ hr embrittlement only for steel > Rockwell C40 no treatment for other material	Class 1
450 °F for 4+ hr hardness must be > 800 HK100	Class 2
360 to 390°F for 1-1.5 hr adhesion non heat-treatable aluminum	Class 3
240 to 260°F for 1-1.5 hr adhesion heat-treatable aluminum	Class 4
1-13% phosphorus by weight	All Classes

Requirement	Callout
xxx% phosphorus	Type I
1-3% phosphorus	Type II
2-4% phosphorus	Type III
5-9% phosphorus	Type IV
No heat treatment	Class 1
260 to 400°C for 2-4 hr hardness must be > 850 HK100	Class 2
180 to 200°C for 1 hr min embrittlement bake for steels	Class 3
120 to 130°C for 1 hr min for heat-treatable alloys	Class 4
140 to 150°C for 1 hr min for non heat-treatable alloys	Class 5
300 to 320°C for 1 hr min adhesion bake for titanium alloys	Class 6