Diablo Pilot Drill Bit DHS4BITII 1/4 x 3 7/8 Inch Bi Metal (Snap Lock Plus Mandrel Deep Cut Hole Saw Wood Metal Plastic 2 3/8 Drilling Depth)

Diablo DHS4BITII 1/4-Inch x 3-7/8-Inch Bi-Metal Hole Saw Pilot Drill Bit

The Diablo DHS4BITII is a 1/4-inch diameter by 3-7/8-inch overall length bi-metal pilot drill bit engineered to provide stable pilot tracking for deep-cut hole saws up to 2-3/8 inches (2.375 in) deep. Manufactured in Switzerland from high-speed bi-metal alloy for maximum heat resistance and extended wear life, this precision pilot bit integrates directly into Diablo Snap-Lock Plus mandrel assemblies. Designed for plumbers, electricians, and carpenters operating handheld drills or drill presses with a 3/8-inch minimum chuck capacity, it penetrates wood framing, sheet metal, and plastic composites to prevent hole saw cup walking during heavy-duty hole cutting.

Best Used For:

• Deep Timber & Joist Pipe Penetrations: Guiding 2-3/8-inch deep-cut hole saws through double 2x4 studs and floor joists for plumbing drain lines.
• Sheet Metal & Enclosure Knockout Cutting: Centering hole saw cups accurately through steel distribution panels, electrical junction boxes, and metal ductwork.
• Plastic Composite & PVC Conduit Drilling: Establishing precise center starts through thick PVC piping, synthetic decking, and fiberglass paneling without material splintering.

Key Performance & Safety Features

• Swiss-Forged Bi-Metal Construction: High-speed steel alloy edge resists high friction heat and cutting wear across wood, metal, and plastic materials.
• Snap-Lock Plus Mandrel Integration: Designed for rapid, tool-free bit swaps and instant locking within Diablo quick-change hole saw systems.
• 2-3/8-Inch Maximum Drilling Depth Reach: Extended 3-7/8 inch overall shaft length allows single-pass drilling through thick structural wood assemblies.
• 1/4-Inch Precision Guide Shaft: Accurately sized center pilot keeps hole saw cups running true to eliminate rotational chatter and hole enlargement.
• Optimized High-Speed Flute Geometry: Fast material evacuation flutes clear wood chips and metal shavings quickly to reduce thermal buildup.
• Universal 3/8-Inch Chuck Compatibility: Fits securely into standard 3/8-inch and 1/2-inch drill chucks, quick-change mandrels, and drill press spindles.

What's Included

• (1) Diablo 1/4" x 3-7/8" Bi-Metal Hole Saw Pilot Bit (DHS4BITII)

Technical Specifications

Pro-Tip: Tighten the set screw on your Snap-Lock Plus mandrel directly onto the flat notch of the pilot bit shank to prevent axial movement under heavy rotational torque.