Milwaukee 48-20-4330 Spline Drill Bit 3/4 Inch 4-cutter

Product Description

The MILWAUKEE 48-20-4330 is a spline-shank rotary hammer drill bit engineered for drilling into brick, block, concrete, and reinforced concrete. The bit uses a 4-cutter tip geometry arranged in a 4 x 90-degree configuration, which reduces the risk of locking up when the bit contacts rebar. Patented rebar chamfers extend service life in reinforced concrete applications. A high-volume flute runs the length of the bit to evacuate debris quickly and maintain drilling speed. This bit is installed by electricians, plumbers, HVAC technicians, concrete contractors, and general trade professionals who routinely core or anchor into masonry and concrete substrates.

This spline bit is suited for residential and commercial applications where rotary hammer drilling into masonry is required. Typical uses include setting anchor bolts, running conduit penetrations, installing sleeves through concrete block walls, and drilling for mechanical fasteners in reinforced slabs. The spline shank is compatible with rotary hammers that accept spline-drive tooling. With a 3/4-inch diameter and 6-inch drilling depth, it handles the hole sizes most common in structural anchor and penetration work.

Key Features

• 4-cutter tip with 4 x 90-degree geometry reduces rebar lock-up during drilling
• Patented rebar chamfers increase bit durability in reinforced concrete
• High-volume flute design accelerates debris removal and maintains drilling rate
• 3/4-inch cutting diameter suits standard anchor and penetration applications
• Spline shank for use with spline-drive rotary hammers
• 6-inch drilling depth with 11-inch overall length

Compatibility

Designed for use with spline-drive rotary hammers. Compatible with rotary hammer tools that accept the spline shank interface. Suitable for drilling brick, block, concrete, and reinforced concrete.

Installation Notes

Installation is performed by licensed tradespeople or qualified contractors using a spline-drive rotary hammer. Confirm the tool is set to rotary hammer mode and powered off before inserting or removing the bit. Eye protection and hearing protection are required when operating rotary hammers in masonry. Do not use this bit with standard drill or hammer-drill chucks that do not accept spline tooling.