RUKO STB-HSS-TiN Step Drill Bit 7/8-1-1/8 Inch

Creating clean, burr-free holes in thin sheet metal often requires multiple drill bits and tedious deburring. The RUKO STB-HSS-TiN step drill bit solves this by combining three precise diameters—7/8", 1", and 1-1/8"—into a single tool, allowing you to enlarge holes progressively without changing bits.

Who is it for

Professional metalworkers, electricians, and plumbers who regularly drill holes in sheet metal, non-ferrous metals, plastics, and stainless steel up to 4 mm thick. It is ideal for control panels, enclosures, and conduit knockouts.

Main features

• High-speed steel (HSS) body with titanium nitride (TiN) coating for extended life and reduced friction
• Three step diameters: 7/8", 1", and 1-1/8" (22.2 mm, 25.4 mm, 28.6 mm)
• Spiral flute design for efficient chip evacuation and smooth cutting
• 118° point angle for accurate starting and reduced walking
• Cylindrical shank with 10 mm diameter fits standard drill chucks
• Compact 90 mm overall length for access in tight spaces

Specifications

• Tool type: Step drill bit
• Material: High-speed steel (HSS)
• Coating: Titanium nitride (TiN)
• Step diameters: 7/8", 1", 1-1/8" (22.2 mm, 25.4 mm, 28.6 mm)
• Number of steps: 3
• Step increment: 1/8" (3.175 mm)
• Shank type: Cylindrical
• Shank diameter: 10 mm
• Total length: 90 mm
• Maximum material thickness: 4 mm
• Point angle: 118°
• Flute type: Spiral
• Cutting edges: 2
• Recommended applications: Sheet metal, non-ferrous metals, plastics, stainless steel
• Measurement system: Imperial with metric equivalents
• Standards: DIN 1412 C (point geometry)

Tips

Use cutting fluid when drilling stainless steel to prolong bit life. For best results, start with a pilot hole equal to the smallest step diameter and maintain steady pressure to prevent chatter.