Irwin 10234CB Cobalt Step Drill Bit 3/16 to 7/8 in 12 Steps

Product Description

The IRWIN 10234CB is a cobalt step drill bit designed to drill multiple hole sizes in a single operation without requiring a bit change. Built from M35 cobalt steel, it handles ferrous metals, stainless steel, and other hard materials that standard high-speed steel bits struggle with. The bit covers 12 hole sizes ranging from 3/16 inches to 7/8 inches in diameter, with 1/16-inch step increments. A 3/8-inch hex shank provides secure chuck engagement and resists slipping under torque. The speed point tip starts on contact without a center punch, reducing walkoff on flat sheet metal. This is a general-purpose bit for electricians, plumbers, HVAC techs, and sheet metal workers who regularly drill clean, sized holes in metal panels and enclosures.

This step drill bit is suited for residential and light commercial trade work where drilling through steel electrical boxes, HVAC cabinets, sheet metal duct fittings, or plumbing access panels is routine. The 12-step format eliminates the need to swap between individual twist bits when multiple hole diameters are needed in a single layout. The bright, uncoated finish is standard for cobalt tools and allows visual inspection of the cutting edges. It is a practical single-bit solution for any tradesperson who regularly works with sheet stock up to 3/16-inch thickness.

Key Features

• M35 cobalt steel construction for durability in hard and abrasive metals
• 12 hole sizes from 3/16 inches to 7/8 inches in one bit
• 1/16-inch step increments for precise hole sizing without guesswork
• 3/8-inch hex shank for positive chuck grip and anti-slip retention
• Speed point tip starts on contact and reduces walkoff on sheet metal
• Bright uncoated finish allows easy inspection of cutting edge condition

Compatibility

Designed as a general-purpose cobalt step drill bit compatible with standard 3/8-inch and larger hex-shank drill chucks and impact-rated drivers used in trade applications.

Installation Notes

Step drill bits are installed by electricians, HVAC technicians, plumbers, and sheet metal workers using standard corded or cordless drills with 3/8-inch or larger chuck capacity. Ensure the workpiece is secured before drilling to prevent spinning and injury. Use cutting fluid on stainless steel or thick-gauge ferrous material to extend bit life. Inspect cutting edges before use and retire the bit if steps show significant wear or chipping.