Step Drill 3-12/4-12/4-20 HSS Straight Groove Step Drill Bit Titanium Coated Hole Cutter, Cone Drill Pieces 3pcs

suitable for drilling holes in steel, brass, wood, plastic, thin iron plate, aluminum, insulating board, PVC board and other materials.
Material: High Speed Steel
Rotating speed:
4-12 speed:260-400
4-20 Speed:180-240
Length:
3-12mm Length: Approx. 7.9cm/ 3.11"
4-12mm Length: Approx. 6.7cm/ 2.60"
4-20mm Length: Approx. 7.2cm/ 2.84"
The Cutters Come in the Following Sizes:
3-12mm(3mm,4mm,5mm,6mm,7mm,8mm,9mm,10mm,11mm,12mm) 10 Steps
4-12mm: (4mm, 6mm, 8mm, 10mm, 12mm) 5 Steps
4-20mm:( 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm）9 Steps
Package includes:
1 x Drill Bit 3-12mm
1 x Drill Bit 4-12mm
1 x Drill Bit 4-20mm
1x Bag