Type N - Bronze / Steel lubrication possible
Type W - Steel PTFE / Steel, self lubricated
GN 648.8 Ball Joints
They can be used for many different mounting applications and are available with a self lubricating option.
Type N (lubrication possible)
Bearing socket - Brass, CuSn8
Internal ring - Steel 100 Cr6, hardened, ground, polished
Type W (self lubricated)
Bearing socket - Steel, zinc plated, with PTFE-insert
Internal ring - Steel, 100Cr6, hardened, ground, polished
Also available in stainless steel.