HSS bi-metal holesaw 20mm.  For cutting metals including stainless steel and non-ferrous metals, wood and plastics.  Fits all standard A1 type arbors with 1/2" UNF thread.
Bi-metal holesaws have a steel body with the edge including the teeth welded to the body. The edge is made of a different metal for maximum cutting performance and wear resistance, in this case high-molybdenum steel.
For best results use cutting oil or spray, and use the correct drill speed: wood 1050rpm, steel 445rpm, stainless steel 220rpm, aluminium 660rpm, other non-ferrous metals 580rpm.
We also have on our website arbors and spare pilot drills for bi-metal holesaws.