These are Brass.
Joes Racing 32489 HIGH PRESSURE TIRE INFLATOR W/ QUICK FILL VALVE, 0-150 PSI
YzusGomumu High Pressure Red Seat Height Adjust Air Valve Rocker Switch...
GSC P-D High Pressure Conical Valve Spring Ti Retainer Kit Fits Nissan VR30DDTT
Diesel High Pressure Relief Valve 0029 Fits For 2003-07 Cummins 5.9L 2500 3500
Diesel High Pressure Relief Valve Fits For RAM 2500 03-07 5.9L 1110010029 US
GSC Power Division For Nissan RB26DETT High Pressure Shimless Valve Spring & Ti