Milwaukee 48-20-4315 Spline Drill Bit 5/8 in X 27 in 4-cutter

Product Description

The MILWAUKEE 48-20-4315 is a spline-shank rotary hammer drill bit engineered for drilling into brick, block, concrete, and reinforced concrete. The 5/8 inch diameter bit uses a 4-cutter head with a 4 x 90 degree tip geometry designed to reduce lock-up when the bit contacts rebar. Patented rebar chamfers along the cutting edge extend durability under repeated impact loads. A high-volume flute clears debris quickly to maintain drilling speed and reduce heat buildup. Installed by commercial and residential concrete contractors, masonry tradespeople, and journeyman electricians and plumbers core-drilling through structural slabs and CMU walls.

This bit is suited for rotary hammer applications in residential and commercial construction where frequent penetration of reinforced concrete is required. The spline drive shank mates with SDS-spline rotary hammer chucks, making it a direct fit for full-size rotary hammers used in foundation work, anchor setting, conduit penetrations, and structural attachment points. With a 22 inch drilling depth and 27 inch overall length, it handles deep penetrations through thick concrete walls and floors in a single pass without extensions.

Key Features

• 4-cutter 4 x 90 degree tip geometry reduces lock-up when drilling through rebar
• Patented rebar chamfers increase cutting edge durability in reinforced concrete
• High-volume flute design promotes fast debris evacuation and sustained drilling speed
• 5/8 inch diameter with 22 inch drilling depth suits thick slab and wall penetrations
• Spline shank provides positive engagement with full-size SDS-spline rotary hammer chucks
• 27 inch overall length allows deep single-pass drilling without bit extensions

Compatibility

Designed for use with full-size SDS-spline rotary hammers. The spline shank is not compatible with SDS-plus chucks; verify chuck type before installation.

Installation Notes

Installation should be performed by a qualified tradesperson familiar with rotary hammer operation and applicable safety codes. Confirm the rotary hammer is powered off and unplugged before inserting or removing the bit from the chuck. Wear appropriate PPE including eye protection and hearing protection during operation. Do not use in hammer-only mode without rotation, as this can overheat and damage the carbide tip.

Technical Specifications

• Shank Type: Spline
• Diameter: 5/8 inches
• Overall Length: 27 inches
• Drilling Depth: 22 inches
• Cutter Configuration: 4-cutter head
• Tip Geometry: 4 x 90 degrees
• Weight: 1.62 pounds
• Application: Brick, block, concrete, reinforced concrete
• UOM: Each

Standard Information

• Brand: MILWAUKEE
• Manufacturer Part Number: 48-20-4315