Milwaukee 48-20-4320 Spline Drill Bit 5/8x36 Inch 4-cutter

Product Description

The MILWAUKEE 48-20-4320 is a spline-shank rotary hammer drill bit engineered for drilling through brick, block, concrete, and reinforced concrete. The 4-cutter head uses a 4 x 90 degree tip geometry that reduces the risk of lock-up when the bit contacts rebar. Patented rebar chamfers extend service life under demanding conditions, and a high-volume flute clears debris quickly to maintain drilling speed. At 5/8 inch in diameter and 36 inches in overall length, this bit is built for deep-hole applications in structural masonry work.

This bit is suited for residential and commercial concrete drilling tasks where a spline-drive rotary hammer is the primary tool. Typical applications include anchor hole drilling, core layout, and penetration work in reinforced concrete slabs, block walls, and brick construction. The 31-inch drilling depth makes it practical for through-slab and thick-wall applications where shorter bits fall short. Concrete and masonry tradespeople, as well as structural installers and general contractors, will find this bit appropriate for production drilling environments.

Key Features

• 4-cutter 4 x 90 degree tip geometry reduces lock-up risk in rebar
• Patented rebar chamfers increase bit durability in reinforced concrete
• High-volume flute design accelerates debris removal during drilling
• Spline shank for secure, positive engagement with spline-drive rotary hammers
• 36-inch overall length with 31-inch usable drilling depth
• 5/8-inch diameter suits common anchor and penetration hole requirements

Compatibility

Designed for use with spline-drive rotary hammer drills. Fits any rotary hammer accepting a standard spline shank interface.

Installation Notes

Installation of this bit requires a spline-drive rotary hammer; confirm the hammer chuck accepts a spline shank before use. Disconnect or de-energize the tool before inserting or removing the bit. When drilling near rebar, maintain steady feed pressure and allow the 4-cutter geometry to work through the obstruction without forcing the tool. Eye protection and dust control measures are recommended when drilling concrete or masonry per applicable OSHA and jobsite safety requirements.

Technical Specifications

• Shank Type: Spline
• Diameter: 5/8 inch
• Overall Length: 36 inches
• Drilling Depth: 31 inches
• Cutter Configuration: 4-cutter, 4 x 90 degree tip geometry
• Application: Brick, block, concrete, reinforced concrete
• Weight: 1.91 pounds
• UOM: Each

Standard Information

• Brand: MILWAUKEE
• Manufacturer Part Number: 48-20-4320