RUKO STB-HSS-TiN Step Drill Bit 3/16 inch-7/8 inch (12 Steps) TiN Coated HSS

The RUKO STB-HSS-TiN step drill bit covers a wide range of hole diameters from 3/16" to 7/8" in a single tool, eliminating the need for multiple drill bits when working with sheet metal, non-ferrous metals, plastics, and stainless steel up to 4 mm thick. Its titanium nitride coating increases surface hardness and reduces friction, allowing higher cutting speeds and longer tool life compared to uncoated HSS step drills.

Highlights

• 12 precisely ground steps from 3/16" to 7/8" (4.76–22.23 mm)
• TiN coating for improved wear resistance and chip evacuation
• Self-centering point with 118° point angle for accurate starts
• Cylindrical shank (10 mm) fits standard drill chucks
• Spiral flute design for smooth cutting and deburring

In daily use

This step drill bit is ideal for electricians, plumbers, and metalworkers who frequently need to enlarge holes or create multiple diameters in thin materials. The step design also deburrs the hole edge as it cuts, saving time on secondary operations. Use dry or with cutting oil for best results.

Full specifications

• Material: High-Speed Steel (HSS)
• Coating: Titanium Nitride (TiN)
• Drill type: Step drill bit
• Diameter range: 3/16"–7/8" (4.76–22.23 mm)
• Number of steps: 12
• Step diameters: 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8"
• Shank type: Cylindrical
• Shank diameter: 10 mm
• Overall length: 90 mm
• Max material thickness: 4 mm
• Flute type: Spiral flute
• Point angle: 118°
• Standard: DIN 1412 C

Final note

RUKO step drills are known for their precise grinding and consistent step transitions, making them a reliable choice for professional use.