SDS Plus 4CT MX4™ 1/4" X 4" X 6"

The Milwaukee 48-20-7331 SDS Plus 1/4" x 4" x 6" MX4™ Drill Bit is a professional-grade masonry bit engineered for fast, precise drilling in concrete, brick, and block—especially in applications involving reinforced concrete with rebar.

Built with Milwaukee’s MX4™ 4-cutter solid carbide head, this bit delivers significantly improved durability and stability compared to traditional 2-cutter designs. The four-cutter geometry helps maintain a consistent hole diameter, reduces walking, and improves performance when encountering rebar or hard aggregate.

Its breaker-point tip aggressively fractures concrete for faster penetration, while the reinforced flute design efficiently removes dust and debris to reduce heat buildup and improve drilling speed. The bit also includes a wear mark indicator, signaling when it has exceeded ANSI tolerance for safe and accurate use.

The 1/4-inch diameter makes it ideal for light-duty anchoring and Tapcon-style fasteners, while the 4-inch working depth (6-inch overall length) provides controlled drilling for standard installation tasks.

Key Features:

• MX4™ 4-cutter carbide head for maximum durability in rebar
• Breaker-point tip for fast, aggressive drilling
• Reinforced flutes for improved debris removal and reduced vibration
• Wear mark indicator for end-of-life visibility
• SDS-Plus shank fits all SDS-Plus rotary hammers
• Designed for concrete, masonry, and reinforced concrete

Ideal Applications:

• Installing concrete anchors and fasteners
• Drilling into brick, block, and poured concrete
• Light-duty electrical, plumbing, and mechanical work
• General-purpose masonry drilling