Unique step structure, one drill bit can make hole diameter with a variety of sizes
No need to use centre punch, not easy to break, not easy to shake
Deburring, chamfering, epanding oval holes, with multi functions
Spiral step drill bit is great for processing deep holes, not easy to accumulate the crumbs into holes
Can be used with hand drills, bench drills and etc.

Material: HSS
Color: Golden color
Dimensions (height diameter): 101 31mm, 74 20mm, 63 12mm
Cutting materials: thin sheet iron, aluminum materials, insulation boards, PVC plates, wooden materials thickness within 4mm

Specifications: 4-32,4-20,4-12.
4-32mm (4,6,8,10,12,14,16,18,20,22,24,26,28,30,32)
4-20mm (4,6,8,10,12,14,16,18,20)
4-12mm (4,6,8,10,12)
3 Step drill bit
In wooden case