The Simpson SDS-Max Quad Head Drill Bit, 3/4 in. x 21 in. Carbide is a heavy-duty rotary hammer bit engineered for demanding concrete drilling in reinforced structures. Built on a chromium-nickel-molybdenum steel alloy body with uniformly brazed carbide inserts and a quad-head design, this bit delivers the speed, precision, and durability that structural and commercial concrete work requires. Its high-volume, double-helix flute geometry channels concrete dust efficiently out of the hole, while the 4 x 90 deg. head geometry is purpose-built to crush through rebar without sticking - making it a reliable choice for professionals drilling anchor, fastener, and structural holes in reinforced concrete.

Key Features

• Uniformly Brazed Carbide Inserts - Precision brazing ensures consistent carbide seating across every insert, extending bit life and maintaining reliable cutting performance throughout the full service life of the bit.
• Self-Centering Tips - Starts on target from the first contact, reducing the need for repositioning and improving hole placement accuracy on every application.
• Chromium-Nickel-Molybdenum Steel Alloy Body - Premium alloy construction provides exceptional resistance to hammering stress and bending forces, supporting extended service life under sustained heavy use.
• Heat-Treatment and Shot-Peened Finish - Advanced heat-treatment procedures combined with a shot-peened surface finish increase surface hardness, boost drilling speed, reduce bit wear, and improve resistance to bending forces.
• 4 x 90 deg. Quad-Head Geometry - Crushes through rebar and prevents the bit from sticking in reinforced concrete, keeping production moving on rebar-dense pours and structural slabs.
• High-Volume, Multi-Flute Spiral - Quickly channels concrete dust out of the hole as the bit advances, reducing clogging and improving drilling speed on deep holes up to 17 in.
• Patented Reinforced Core Flute Design - The high-performance, reinforced core flute maximizes energy transfer from the rotary hammer into the drill tip, optimizing impact efficiency on every stroke.
• ANSI Standard B212.15 Compliant - Conforms to the established industry standard for rotary hammer drill bits, providing assurance of dimensional and performance consistency for professional applications.

Why This Product

• Built to handle reinforced concrete without slowing down - The 4 x 90 deg. quad-head geometry is specifically designed to crush through rebar and resist sticking, so crews drilling anchor or fastener holes in reinforced slabs and walls can maintain pace without stopping to free a stuck bit.
• Engineered to reduce operator fatigue on long drilling runs - The proprietary flute geometry reduces vibration and noise by optimizing impact energy transfer from the rotary hammer into the bit tip, putting less stress on the operator during extended use.
• Premium materials chosen for longevity, not just initial performance - From the uniformly brazed carbide inserts to the heat-treated, shot-peened alloy body, every material and process decision targets reduced bit wear and a longer service life, lowering the cost per hole over time.
• A complete solution for deep-hole SDS-max drilling - With a 21 in. overall length and a 17 in. drilling depth, this bit reaches where shorter bits cannot, making it well suited for through-slab and deep embedment anchor applications that demand both reach and precision.

Specifications

• Model Number (MPN): MDMX07521Q
• Brand: Simpson Strong-Tie
• Shank Type: SDS-max Shank
• Head Type: Quad Head (4x Drill Bit)
• Diameter: 3/4 in.
• Overall Length: 21 in.
• Drilling Depth: 17 in.
• Material: Hardened Steel (Chromium-Nickel-Molybdenum Steel Alloy Body)
• Tip Material: Carbide
• Industry Standard: ANSI Standard B212.15
• Country of Origin: Germany

Approved Applications

• Drilling into reinforced concrete where rebar penetration resistance is required
• High-speed concrete drilling with SDS-max rotary hammer tools
• Structural and commercial concrete drilling requiring precise hole placement
• Demolition and heavy-duty drilling applications demanding reduced operator fatigue
• Applications requiring conformance to ANSI Standard B212.15

What's Included

• 1x Simpson Strong-Tie MD