Irwin IR15103ZR Step Drill Bit 1/4 to 3/4 Inches 9 Holes

Product Description

The IRWIN IR15103ZR is a 3T step drill bit designed to drill multiple hole sizes with a single bit. It covers 9 hole sizes ranging from 1/4 inches to 3/4 inches in 1/16 inches increments. Step drill bits like this one are used when a clean, precise hole is needed in sheet metal, plastic, or thin-gauge material without requiring a pilot hole or bit change. The stepped geometry allows the technician to stop at any diameter within the range, reducing tool changes and saving time on the job. Electricians, HVAC installers, and plumbers commonly reach for step bits when punching holes in electrical enclosures, sheet metal ductwork, and utility panels.

This bit is suited for use in residential and light commercial service work where multiple hole diameters are needed in a single operation. Typical applications include drilling knockout holes in electrical boxes, control panels, HVAC equipment cabinets, and conduit entry points. The 1/16 inches increment steps provide precise diameter control across the 1/4 inches to 3/4 inches range, making it a practical carry tool for field technicians who need versatility without carrying a full set of individual bits.

Key Features

• 9 hole sizes in a single bit, ranging from 1/4 inches to 3/4 inches
• 1/16 inches step increments for precise diameter control
• 3T step geometry reduces walking and produces clean entry holes
• Single-bit solution eliminates multiple tool changes during field work
• Sold individually — one bit per unit

Compatibility

Designed for use in thin-gauge sheet metal, plastic sheeting, and similar materials common in electrical, HVAC, and plumbing rough-in and service work.

Installation Notes

Step drill bits are installed and operated by electricians, HVAC technicians, and plumbers using a standard corded or cordless drill driver. Apply consistent, moderate pressure and allow the stepped flutes to clear chips between passes. Secure the workpiece before drilling to prevent spinning or shifting. Wear appropriate eye protection and follow applicable OSHA and NEC guidelines for working near electrical enclosures.

Technical Specifications

• Bit Type: 3T Step Drill Bit
• Number of Hole Sizes: 9
• Hole Size Range: 1/4 inches to 3/4 inches
• Step Increments: 1/16 inches
• Sold As: Each
• Minimum Order Quantity: 1
• UPC: 038548151038

Standard Information

• Brand: IRWIN
• Manufacturer Part Number: IR15103ZR