Steel bodies are 12L14 material with black oxide or zinc plate finish.
Bodies are color coded.
Plain is 303 stainless steel.
Silver is zinc plated steel - light pressures.
Black is black oxide steel - medium pressures.
Gold is gold chromate finish - heavy pressures.
The nylon locking element holds the plunger body securely in place without the need for lock nuts or other devices. We recommend a 90 degree countersink 1/32" larger than the major diameter of the mating thread to prevent damaging the element.