Product name: Triangular shank spiral groove step drill. (Pagoda Drill)

Specifications: 4-32mm (4,6,8,10,12,14,16,18,20,22,24,26,28,30,32mm) 10mm handle.

  4-20mm (4,6,8,10,12,14,16,18,20mm) 8mm handle.

  4-12mm (4,5,6,7,8,9,10,11,12mm) 6mm handle.

Special reminder: When you hit the steel plate, you must inject water to cool it. The drill bit will easily temper due to high temperature and smoke during use. If you insist on doing this, the drill bit will soon be scrapped.