Milwaukee 48-20-4057 Spline Drill Bit 9/16 X 23 Inch

Product Description

The MILWAUKEE 48-20-4057 is a spline-shank rotary hammer drill bit built for drilling into brick, block, and concrete. The 2-cutter head design speeds up material removal while the spline drive shank transfers maximum torque from the hammer drill to the bit. At 9/16 inch in diameter with an overall length of 23 inches and an 18-inch drilling depth, this bit handles deep anchor holes and pass-through penetrations common in commercial and residential masonry work. Licensed electricians, plumbers, and HVAC technicians routinely use bits in this class for core-path penetrations through concrete block walls and poured foundations.

This bit is suited for applications where a spline-drive rotary hammer is already on site. Typical use cases include setting anchor bolts, running conduit sleeves through block walls, and drilling through poured concrete slabs or footings. The 18-inch usable drilling depth gives enough reach for most above-grade wall thicknesses encountered in light commercial construction. The bit ships as a 2-count pack, making it practical to keep a spare on the truck during production drilling days.

Key Features

• 9/16 inch diameter with a 2-cutter head for efficient chip removal in masonry
• Spline shank for positive drive engagement and maximum torque transfer
• 18-inch drilling depth accommodates thick concrete and block walls
• 23-inch overall length provides clearance in tight or recessed drilling positions
• 2-cutter bit pack included per SKU

Compatibility

Designed for use with spline-drive rotary hammer drills. Compatible with any rotary hammer that accepts a standard spline-drive chuck.

Installation Notes

Spline-drive rotary hammer bits are installed and removed by a licensed trade professional or qualified installer following the rotary hammer manufacturer's operating instructions. Always wear appropriate PPE including eye protection and hearing protection when operating rotary hammer equipment. Confirm the drilling area is clear of embedded conduit, rebar, or utility lines before beginning. Allow the bit to cool between extended drilling cycles to preserve carbide tip integrity.

Technical Specifications

• Bit Diameter: 9/16 inch
• Overall Length: 23 inches
• Drilling Depth: 18 inches
• Shank Type: Spline
• Cutter Head: 2-Cutter
• Quantity: 2 per pack
• Weight: 1.26 pounds
• UPC: 0045242102471

Standard Information

• Brand: MILWAUKEE
• Manufacturer Part Number: 48-20-4057