The Simpson MDMX10021Q 1 in. x 21 in. SDS-max Shank Quad-Head Drill Bit from Simpson Strong-Tie is a premium carbide-tipped rotary hammer bit engineered for professional concrete and reinforced concrete drilling applications. Built on a proprietary quad-head dual-cutter design with a high-volume, double-helix flute geometry, this bit is purpose-built to maximize drilling speed, extend service life, and reduce stress and vibration on the operator - even in the most demanding structural drilling conditions.

Key Features

• Uniformly brazed carbide inserts - provide consistent tip integrity across the full cutting surface, resulting in longer bit life and more reliable performance hole after hole
• Self-centering tips - eliminate bit walk at the start of each hole for accurate placement and cleaner results, saving time on layout-critical work
• Chromium-nickel-molybdenum steel alloy body - delivers the hammering resilience and structural toughness required for extended service life under heavy rotary hammer use
• Heat-treatment procedures and shot-peened finish - increase surface hardness and drilling speed, reduce bit wear, and improve resistance to bending forces so the bit holds up under sustained impact loading
• High-volume, multi-flute spiral - quickly channels concrete dust from the hole during drilling, maintaining consistent speed and preventing clogging at depth
• 4 x 90 deg. quad-head geometry - crushes through rebar and prevents the bit from sticking in reinforced concrete, keeping work moving on structural applications where other bits struggle
• Proprietary flute geometry - reduces vibration and optimizes impact energy transfer from the rotary hammer into the drill bit tip, improving drilling speed and durability while reducing noise and physical strain on the operator
• Conforms to ANSI Standard B212.15 - ensures the bit meets recognized dimensional and performance standards for SDS-max rotary hammer drill bits

Why This Product

• Built to power through reinforced concrete - the 4 x 90 deg. quad-head dual-cutter design is specifically engineered to crush through rebar without binding, making this bit a dependable choice for structural concrete drilling where hitting steel is a routine obstacle
• Engineered to reduce operator fatigue - the proprietary flute geometry optimizes energy transfer and reduces vibration, meaning less physical stress on the operator during extended or repeated drilling on large-scale jobs
• Premium materials built for long-term durability - uniformly brazed carbide inserts, a chromium-nickel-molybdenum alloy body, and a heat-treated, shot-peened finish work together to resist wear, bending forces, and premature tip failure, reducing the frequency of bit replacement on demanding projects
• Precision and speed in a single package - self-centering tips deliver accurate hole placement from the first contact, while the high-volume multi-flute spiral clears concrete dust continuously, so crews can work faster and with greater confidence across anchor installation, doweling, and other concrete boring applications

Specifications

• MPN: MDMX10021Q
• Brand: Simpson Strong-Tie
• Shank Type: SDS-max Shank
• Head Type: Quad Head 4x Drill Bit
• Diameter: 1 in.
• Overall Length: 21 in.
• Drilling Depth: 17 in.
• Material: Hardened Steel (Chromium-Nickel-Molybdenum Steel Alloy)
• Tip Material: Carbide
• Standards Compliance: ANSI Standard B212.15
• Country of Origin: Germany

Frequently Asked Questions

What type of rotary hammer is this drill bit compatible with?

This drill bit features an SDS-max shank, making it compatible with all SDS-max rotary hammers. The shank's chisel-shaped head is designed to penetrate material efficiently while directing concrete dust into the multi-flute spiral.

Can this drill bit be used in reinforced concrete with rebar?

Yes. The 4 x 90 deg. quad-head geometry is specifically engineered to crush through rebar and prevent the bit from sticking in reinforced concrete, making it well-suited for demanding structural drilling applications.

What is the maximum drilling depth this bit can achieve?

This bit provides a drilling depth of 17 in., with an overall length of 21 in. The high-volume, multi-flute spiral quickly channels concrete dust away from the hole to maintain drilling speed throughout the full depth.

What design features help reduce operator fatigue and vibration?

The proprietary flute geometry reduces vibration and optimizes impact energy transfer from the rotary hammer into the drill bit tip. Combined with the shot-peened finish and heat-treated chromium-nickel-molybdenum steel alloy body, these features work together to reduce noise, stress, and vibration on the operator during extended use.

Note: Product dimensions may differ from picture. Please see the item description above for specifications.