Milwaukee 48-20-4325 Spline Drill Bit 11/16 in 4-cutter

Product Description

The MILWAUKEE 48-20-4325 is a spline-shank rotary hammer drill bit engineered for drilling into brick, block, concrete, and reinforced concrete. The 4-cutter head uses a 4 x 90-degree tip geometry that reduces the risk of lockup when the bit contacts rebar. Patented rebar chamfers extend cutting-edge durability under repeated impact loading. A high-volume flute design accelerates debris evacuation from the hole, keeping the bit running cool and reducing cycle time. The spline shank is compatible with spline-drive rotary hammers. This bit is sized at 11/16-inch diameter with a 16-inch overall length and an 11-inch drilling depth.

This bit is suited for commercial and residential masonry and concrete work where a spline-drive rotary hammer is the tool of choice. Typical applications include anchor hole drilling, core layout drilling, and penetration work in poured concrete walls, CMU block, and brick. The 4-cutter geometry makes it particularly useful in reinforced concrete slabs and walls where rebar encounters are common. It is installed and operated by licensed electricians, plumbers, HVAC technicians, and general contractors who require reliable, repeatable hole placement in hard substrates.

Key Features

• 4-cutter 4 x 90-degree tip geometry reduces lockup on rebar contact
• Patented rebar chamfers extend cutting-edge durability in reinforced concrete
• High-volume flute design promotes fast debris removal and reduced heat buildup
• Spline shank provides positive drive engagement in spline-drive rotary hammers
• 11/16-inch diameter with 11-inch drilling depth suits common anchor and penetration specs
• 16-inch overall length allows reach through thick substrates without extension

Compatibility

Designed for use with spline-drive rotary hammers. Compatible with drilling applications in brick, block, poured concrete, and reinforced concrete.

Installation Notes

Install and remove spline bits only when the rotary hammer is powered off and disconnected from its power source. Ensure the spline shank is fully seated and locked in the tool chuck before operation. Eye protection and hearing protection are required when operating rotary hammer equipment. Inspect the cutting edges and shank for wear or damage before each use and replace the bit if deformation is observed.

Technical Specifications

• Diameter: 11/16 inches
• Overall Length: 16 inches
• Drilling Depth: 11 inches
• Shank Type: Spline
• Cutter Configuration: 4-Cutter Head
• Weight: 1.29 pounds
• Sold As: Each

Standard Information

• Brand: MILWAUKEE
• Manufacturer Part Number: 48-20-4325