The Simpson SDS-Max Quad Head Drill Bit 1-1/8 in. x 21 in. Carbide is a premium heavy-duty rotary hammer bit engineered by Simpson for demanding concrete and reinforced concrete drilling applications. Built around a chisel-shaped, quad-head carbide tip and a high-volume, double-helix multi-flute spiral, this bit is designed to transfer maximum impact energy from the rotary hammer into the cutting surface - accelerating drilling speed, reducing operator fatigue, and maintaining accuracy even in the toughest substrates. Its proprietary flute geometry minimizes vibration while efficiently channeling concrete dust out of the hole, keeping operations clean and efficient from start to finish.

Key Features

• Uniformly Brazed Carbide Inserts - Consistent bonding across all cutting edges means the bit maintains its cutting performance over an extended service life, reducing the frequency of bit replacement on the job.
• Self-Centering Tips - Accurate hole placement from the very first strike prevents bit walking on hard surfaces, saving time and protecting the integrity of the work surface.
• Chromium-Nickel-Molybdenum Steel Alloy Body - This premium steel alloy construction delivers exceptional hammering quality and long-term durability under the sustained stress of heavy-duty rotary hammer use.
• Heat-Treatment and Shot-Peened Finish - Specialized heat-treatment procedures combined with a shot-peened finish increase surface hardness, improve drilling speed, reduce drill bit wear, and improve resistance to bending forces - keeping the bit performing reliably under load.
• 4 x 90 deg. Quad-Head Geometry - The four-point head design crushes through rebar and prevents the bit from sticking in reinforced concrete, reducing downtime and keeping drilling operations moving efficiently.
• High-Volume, Multi-Flute Spiral - Rapidly channels concrete dust away from the cutting zone and out of the hole, improving drilling speed and reducing heat buildup at the tip.
• ANSI Standard B212.15 Compliant - Conforms to established industry tolerances, giving contractors confidence that the bit meets recognized dimensional and performance standards.
• Patented Reinforced Core Flute Design - The high-performance reinforced core maximizes energy transfer from the rotary hammer into the drill tip, enhancing both speed and durability in continuous use.

Why This Product

• Built for Reinforced Concrete Without Slowdowns - The 4 x 90 deg. quad-head geometry is specifically engineered to crush through rebar rather than bind against it, making this bit a dependable choice for post-installed anchor holes and structural drilling in heavily reinforced slabs and walls.
• Engineered to Reduce Operator Fatigue - The proprietary flute geometry is designed to optimize impact energy transfer while reducing noise, stress, and vibration transmitted to the operator - an important factor during extended drilling sessions on large commercial or industrial projects.
• Premium Materials Built to Last - Uniformly brazed carbide inserts, a chromium-nickel-molybdenum steel alloy body, and a heat-treated shot-peened finish combine to extend bit life and reduce wear, lowering the overall cost per hole on high-volume drilling tasks.
• Precision Where It Counts - Self-centering tips and ANSI Standard B212.15 compliance work together to ensure accurate, repeatable hole placement - critical when installing anchors that must meet strict embedment and tolerance requirements.

Specifications

• Specification: Detail
• Model Number: MDMX11221Q
• Brand: Simpson Strong-Tie
• Shank Type: SDS-max Shank
• Head Type: Quad Head - 4x Drill Bit
• Diameter: 1-1/8 in.
• Overall Length: 21 in.
• Drilling Depth: 17 in.
• Material: Hardened Steel (Chromium-Nickel-Molybdenum Steel Alloy Body)
• Tip Material: Carbide
• Standard Compliance: ANSI Standard B212.15
• Country of Origin: Germany

Approved Applications

The Simpson Strong-Tie MDMX11221Q S