Bosch Core Pilot Bit T3924 SDS Plus 6 Inch SpeedCore Centering Guide (Carbide Tip Integrated Mandrel Concrete Brick Block Masonry Coring Start)

Bosch T3924 SpeedCore™ 6" SDS-Plus Carbide-Tipped Centering Pilot Bit & Mandrel

The Bosch T3924 SpeedCore™ 6-inch SDS-Plus carbide-tipped pilot bit establishes true, non-walking centering starts across structural brick facades, CMU masonry blocks, and concrete building walls. Engineered to operate in rotary-only drilling mode on SDS-Plus rotary hammers, this precision guide bit centers modular Bosch SpeedCore™ thin-wall core cutters to produce clean, circular entry perimeters with minimal surface blowout. Outfitted with a premium sintered carbide-blend cutting tip that bites into hard masonry aggregate, an integrated steel drive mandrel that locks core cutters securely onto the drive axis, and a slotted SDS-Plus shank, it equips commercial electricians, mechanical contractors, and HVAC technicians with exact hole alignment for conduit and switch box installations.

Best Used For:

• Thin-Wall Masonry Core Centering: Establishing a precise guide track in brick, CMU block, and masonry surfaces to prevent core bit wandering during the initial coring sequence.
• Electrical Switch Box and Receptacle Coring: Aligning large-diameter core cutters accurately to drill recessed electrical enclosure pockets in interior masonry and exterior brick walls.
• HVAC Line and Plumbing Passages: Guiding thin-wall core bits through foundational masonry blocks and limestone backing for mini-split line sets and pipe sleeves.

Key Performance & Safety Features

• Premium Carbide-Blend Tip: Industrial-grade tungsten carbide cutting point delivers clean, immediate hole starts and resists abrasive wear against hard aggregate.
• Integrated Core Mandrel Collar: Built-in mandrel geometry couples thin-wall core bits directly onto the pilot assembly for rapid setup and true rotational tracking.
• Optimized for Rotary-Only Operation: Engineered specifically for rotary mode drilling to establish clean pilot tracks without fracturing brittle brick edges.
• SpeedCore System Compatibility: Seamlessly integrates with the full lineup of Bosch SDS-Plus SpeedCore™ thin-wall rotary hammer core cutters.
• 6-Inch Usable Pilot Reach: Provides 6 inches of guide length to anchor deep into wall substrates before the core teeth engage the masonry surface.
• Heavy-Duty Forged Steel Shank: High-strength alloy steel body withstands high rotational torque and prevents axial deflection during heavy hole cutting.

What's Included

• (1) Bosch T3924 SpeedCore™ 6" SDS-Plus Carbide-Tipped Centering Pilot Bit with Integrated Mandrel

Technical Specifications

Pro-Tip: Drill the pilot hole in "Rotary-Only" mode until the thin-wall core cutter's carbide teeth score an initial 1/4-inch deep circular groove in the masonry; you can then remove the pilot bit to let the core body cut freely at high speed without drag.