The Simpson SDS-Max Quad Head Drill Bit 11/16 in. x 21 in. Carbide is a premium, professional-grade rotary hammer bit engineered for demanding concrete and reinforced concrete drilling applications. Built on a chromium-nickel-molybdenum steel alloy body with uniformly brazed carbide inserts, this quad-head bit pairs a high-volume, double-helix flute design with a patented reinforced core to maximize energy transfer from the rotary hammer into the tip - delivering faster drilling speeds, longer service life, and noticeably reduced vibration and noise for the operator. Conforming to ANSI Standard B212.15 and produced to Simpson's premium quality standards, it is a reliable choice for anchoring, fastening, and penetration work wherever heavy-duty concrete drilling is required.

Key Features

• Uniformly brazed carbide inserts - ensure consistent tip integrity across the full cutting edge, extending bit life and reducing the need for frequent replacements on the job.
• Self-centering tips - allow accurate hole placement from the first contact, minimizing bit walking and improving precision on every bore.
• Chromium-nickel-molybdenum steel alloy body - provides the structural toughness needed to withstand repeated hammer impacts, supporting long-term hammering quality and extended service life.
• Heat-treatment procedures and shot-peened finish - increase surface hardness, improve resistance to bending forces, reduce drill bit wear, and contribute to faster drilling speed through harder materials.
• ANSI Standard B212.15 conformance - confirms the bit meets precise dimensional and performance tolerances, giving professionals confidence in consistent, predictable results.
• High-volume, multi-flute spiral - quickly channels concrete dust out of the hole during drilling, preventing clogging and maintaining drilling speed throughout the bore.
• 4 x 90 deg. head geometry - crushes through rebar and actively prevents the bit from sticking in reinforced concrete, keeping work moving in the most challenging substrate conditions.
• Proprietary flute geometry with patented reinforced core - optimizes impact energy transfer from the rotary hammer into the drill bit tip, reducing operator stress, noise, and vibration during extended use while enhancing overall drilling efficiency.

Why This Product

• Built for reinforced concrete without compromise - the 4 x 90 deg. quad-head geometry is specifically engineered to crush through rebar and resist bit sticking, making this drill bit a dependable choice for anchoring and penetration work in heavily reinforced slabs and walls.
• Operator comfort is designed in, not an afterthought - the proprietary flute geometry reduces vibration and noise at the source by optimizing how impact energy travels from the rotary hammer into the carbide tip, easing fatigue during long drilling sessions.
• Durability features are stacked throughout the construction - uniformly brazed carbide inserts, a heat-treated and shot-peened finish, and a chromium-nickel-molybdenum alloy body work together to resist wear, bending, and tip degradation across a full range of concrete drilling demands.
• Precision and speed on every hole - self-centering tips eliminate bit drift at the start of each bore, while the high-volume double-helix spiral continuously clears concrete dust to sustain drilling speed from the first pass to the last.

Specifications

• Model Number (MPN): MDMX06821Q
• Brand: Simpson Strong-Tie
• Shank Type: SDS-max Shank
• Head Type: Quad Head 4x Drill Bit
• Diameter: 11/16 in.
• Overall Length: 21 in.
• Drilling Depth: 15-1/2 in.
• Material: Hardened Steel (Chromium-Nickel-Molybdenum Steel Alloy Body)
• Tip Material: Carbide
• 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, which is the standard interface for large-format rotary hammers. The SDS-max shank design provides a secure, tool-free bit connection and is the industry-standard shank type for professional-grade rotary hammers used in heavy concrete drilling applications.

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

Yes. The 4 x 90 deg. head geometry is specifically designed to crush through rebar and prevent the bit from sticking in reinforced concrete, making it well suited for demanding applications where rebar may be encountered.

What design features help reduce operator fatigue during use?

The proprietary flute geometry reduces vibration and optimizes impact energy transfer from the rotary hammer into the drill bit tip. This design enhances drilling speed and durability while reducing noise, stress, and vibration on the operator during extended use.

What quality standards does this drill bit meet?

This drill bit conforms to ANSI Standard B212.15, ensuring it meets precise tolerance requirements for professional-grade drilling applications. The chromium-nickel-molybdenum steel alloy body, heat-treatment procedures, and shot-peened finish further ensure it meets the highest industry standards for hardness, durability, and performance.

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