Diablo DAG3090 7/8" x 17-1/2" Deep-Bore High-Speed Auger Bit

The Trade Standard. 17.5" Reach. Optimized for 3/4" Conduit & Pipe Rough-In.

The Diablo DAG3090 is the essential deep-bore tool for electrical and mechanical contractors. With a 7/8" diameter, this bit is precision-engineered to create the ideal clearance for 3/4" conduit, PVC, and copper pipe through the thickest structural members. Its massive 17-1/2" length allows you to drill through multiple floor joists or deep wall headers in a single pass, eliminating the need for extensions or drilling from both sides.

For the professional at The Fastener Group, the DAG3090 is built for cordless dominance. Featuring a self-feeding lead screw, the bit pulls itself into the wood, allowing your drill to do the work while you maintain total control. The induction-hardened dual cutting edges ensure that even after dozens of holes in sap-heavy or pressure-treated lumber, your cuts remain clean and fast.

Key Features & Professional Benefits:

• 7/8" Trade-Sized Diameter: Perfectly sized for running 3/4" electrical conduit and mechanical piping with the necessary clearance for a fast rough-in.
• Extended 17-1/2" Reach: Designed for deep-bore applications in stacked joists, triple-headers, and heavy structural timbers.
• Self-Feeding Screw Tip: Effortlessly pulls the bit through the wood, reducing physical strain and ensuring a consistent feed rate without stalling the drill.
• Dual-Cutting Edge Design: Delivers 2x faster performance than standard bits by shearing wood fibers cleanly, resulting in a smooth, burr-free hole.
• High-Speed Flute Geometry: Specifically engineered for rapid chip evacuation in deep holes, preventing heat buildup and friction that can drain cordless batteries.
• Impact-Rated Quick-Change Shank: Features a 1/4" hex shank that locks securely into all high-torque drills and impact drivers for slip-free performance.
• Induction-Hardened Steel: Offers extreme durability and stays sharp significantly longer than traditional carbon steel auger bits.

Product Specifications:

Precision for the Professional Rough-In

The Diablo DAG3090 is an investment in jobsite speed. By combining Trade-Specific Sizing with Deep-Bore Capability, Diablo has created a tool that solves the most difficult framing and rough-in challenges. For the contractor at The Fastener Group who demands a perfect fit and no-stall reliability, the DAG3090 is the definitive choice for structural drilling.

Stop struggling with undersized bits. Upgrade to the Diablo DAG3090 and master the deep-bore rough-in with 17.5 inches of self-feeding power.

The Deep-Bore Rough-In Kit 

Reach further. Clean faster. Pair your DAG3090 Deep-Reach Bit with these professional-grade essentials for electrical and mechanical installs.

[→ SHOP ALL TIMBER & FASTENING GEAR HERE]

• [SHOCKWAVE Impact 3″ Magnetic Bit Holder] – Extend Your Reach. Deep timber drilling often requires extra clearance. This impact-rated holder provides the reach you need while the high-strength magnet ensures your DAG1130 stays locked in during high-torque applications.
• [Markal Pro-Line HP Liquid Paint Marker (96522) - White] – Mark Wet & Treated Wood. Deep-hole layout often happens on dark, pressure-treated lumber. This liquid paint marker leaves a permanent mark that won't disappear under wood chips or moisture.
• [Stabila 37448 Type 196 48" Heavy-Duty Level] – The Post-Setter’s Standard. If you're drilling 17-inch holes, you're likely setting structural posts. This 4-foot level ensures your large timber runs are perfectly plumb.
• [3M Peltor X1A Over-the-Head Earmuffs] – High-Torque Hearing Protection. Long-bore drilling generates sustained, high-decibel noise. Protect your hearing with these low-profile, comfortable muffs.
• [Watson Impact Gloves] – Heavy-Duty Vibration Dampening. Drilling deep with 1-inch bits creates significant torque. These gloves feature padded palms to reduce hand fatigue and increase grip.