The Greenlee GSB04 is a cobalt multi-hole step bit designed for electricians who need to punch clean, burr-free holes through steel enclosures, aluminium sheet, copper bus, and plastic laminates up to 7/8" without changing bits between sizes. With 12 drill stages, a patented split-step design, and progressive cutting edges, it optimises chip load and torque efficiency to reduce stalling and maximise holes per battery charge — a clear advantage on high-volume panel rough-ins, junction box knockouts, and commercial conduit installations. Cobalt construction delivers superior hardness and heat resistance for extended tool life, complemented by a durable split-point tip, improved double-flute chip evacuation, and laser-marked sizing for fast identification on busy job sites.

Specifications

Type Multi-hole Step Bit, Cobalt
Application Mild steel, aluminium, brass, copper, wood, fibreglass, plastics, and laminates
Number of Drill Stages 12
Minimum Drill Diameter 3/16" (4.8 mm)
Maximum Drill Diameter 7/8" (22.2 mm)
Maximum Sheet Metal Thickness 10 gauge (3.5 mm)
Shank Three-flat, fits all 1/2" drill chucks