In what material are the camloc quarter turns made?

We are using different material for the different styles and different series.

As example, DIN EN 10277-3/10087 1.0727 for V27S06, V26S07 and V26S08 cold heading wire 8740 for V26S01.

for stud 991S02-6-1AGV

Stud is made from steel 1.1147 or 1.1132

Wing is made from steel 1.0333 or 1.0330 or SPCC

Cross pin is made from steel 1.1200

Belleville washers are made from steel 1.1231

For receptacle 26r16-1FGV for instance:
Hard bronze CuZn12Si4 per DIN EN 1982 Cap: brass per STD150-25-1CC

for the 15F series this is:
8740-.124+/-0005HW per SAE AMS 6322

As you can see, there is no general answer...

For latches, you find more information here.