The crinkle washer is made from brass with a nickel plating. The crinkle washer is part number 71X-0043-33.
C-SX-058
C-SX-069
C-SX-101
C-SX-069G
C-SX-088
C-SX-095
C-SX-110
C-SX-126
C-SX-156
C-SX-190
C-SX-220ZZ