Fatigue spalling – Flaking on raceways or rolling elements
Rust & corrosion – Surface rust or pitting on the slew bearing
Burning – Blue-black discoloration from overheating
Cage cracking – Broken rivets or shattered cage in the slew bearing
Indentation – Brinell marks from impact or debris
Creep – Mirror-like slip marks on mating surfaces of the slew bearing
Adhesive wear – Metal transfer and seizure between surfaces
Cracks – Linear fractures on rings or rolling elements
Electrical erosion – Crater-like pits from current discharge on the slew bearing
Abrasion – Uniform wear with reddish-brown particles