Step Drill Bit: Round Step Drill Bit – HSS (4 – 20mm)

Features

• 100% Brand new and high quality!!
• The Drill is not easy to be broken.
• The ladder of its unique structure, a bit can open a variety of specifications of aperture.
• Do not need to use a center punch, compared with the ordinary twist
• Deburring, chamfering, elliptic hole enlargement, and twist drill, the
• Their function of them was unable, but it is possible.
• The use of tools: drill, bench drill. Work while water cooling, can
• Effectively extend the service life of the drill bit, recommend a drilling rate of 250-250 RPM.