Milwaukee 48-20-4138 Spline Drill Bit 1-3/8 in 2-cutter

Product Description

The MILWAUKEE 48-20-4138 is a spline-shank rotary hammer drill bit built for heavy-duty core removal in brick, block, and concrete. The 2-cutter carbide head measures 1-3/8 inches in diameter and delivers aggressive material removal typical of spline-drive hammer drilling applications. With an overall length of 22 inches and a usable drilling depth of 16 inches, this bit handles deep anchor and sleeve installations where standard SDS bits fall short. It ships as a 2-count pack, making it a practical stock item for contractors and service techs running high-volume masonry work.

This bit is suited for residential and commercial masonry drilling tasks including anchor bolt installation, conduit penetrations, and sleeve anchors in poured concrete, CMU block, and brick. The spline shank interfaces with compatible spline-drive rotary hammer tools, providing positive torque transfer and reduced bit slippage during aggressive hammer settings. The extended 22-inch overall length gives clearance when drilling through thick walls or deep into foundation material.

Key Features

• 1-3/8 inch diameter 2-cutter carbide head for fast concrete and masonry penetration
• Spline shank for positive drive engagement with spline-drive rotary hammers
• 22-inch overall length with 16-inch usable drilling depth
• 2-count pack for jobsite redundancy and reduced downtime
• Designed for brick, block, and poured concrete applications

Compatibility

Designed for use with spline-drive rotary hammer tools. Confirm your rotary hammer accepts a spline chuck before installation.

Installation Notes

Installation is performed by licensed electricians, plumbers, or general contractors during anchor and penetration work. Disconnect or de-energize any embedded utilities before drilling and verify wall composition with a detection tool. Always wear appropriate eye and hearing protection when operating a rotary hammer. Follow applicable OSHA silica dust exposure guidelines when drilling concrete or masonry without wet suppression.