Diablo Step Drill Bit DSD1375S15 7/8 to 1 3/8 Inch 15 Steps (3/8 Three Flat Shank 132 Split Point Tip Dual Flute Metal PVC Drilling)

Diablo DSD1375S15 7/8-Inch to 1-3/8-Inch 15-Step Drill Bit

The Diablo DSD1375S15 is a 15-step high-speed step drill bit engineered to expand pilot holes from 7/8-inch to 1-3/8-inch diameters in sheet metal, PVC, and structural plastics up to 1/8-inch (0.125 in) thick. Built with a 132-degree Split Point Tip that eliminates bit walking and pre-drilling requirements, this CNC-milled step bit delivers 2X faster cutting speeds and 6X longer service life than standard step bits. Equipped with a 3/8-inch 3-flat shank to prevent chuck slippage and a dual-flute design that evacuates metal shavings rapidly, it maximizes efficiency for electricians, plumbers, and HVAC technicians executing conduit and pipe knockouts.

Best Used For:

• Electrical Junction Box & Panel Knockouts: Enlarging pre-existing openings in steel switch boxes and enclosure panels for electrical conduit fittings.
• HVAC Sheet Metal Duct & Drain Pipe Sizing: Drilling clean, burr-free passage holes through thin gauge sheet metal ducts and plastic drain pans.
• Plumbing PVC & Plastic Enclosure Hole Enlargement: Sizing entry holes through thick plastic junction boxes, PVC water pipes, and synthetic polymer panels without cracking.

Key Performance & Safety Features

• 132-Degree Self-Centering Split Point Tip: Penetrates materials instantly upon impact to eliminate bit walking and skip the pilot hole step.
• Automated CNC-Ground Cutting Edge Tolerances: Precision-milled step geometry achieves smooth step transitions and rapid chip removal to reduce thermal friction.
• Jam-Free Dual-Flute Architecture: Parallel dual flutes clear metallic debris quickly to prevent material clogging and bit lockup.
• 3/8-Inch 3-Flat Anti-Slip Shank: Three ground flat surfaces lock tightly into standard drill chucks to ensure zero shank slippage under high torque.
• 75% Extended Cordless Battery Runtime: Low-friction cutting geometry reduces drill motor draw to deliver up to 75 percent more holes per charge.
• Laser-Etched Permanent Step ID Markings: High-visibility size indicators across all 15 steps resist chemical wear and friction abrasion for clear depth tracking.

What's Included

• (1) Diablo 7/8" to 1-3/8" 15-Step Drill Bit with 3/8" 3-Flat Shank (DSD1375S15)

Technical Specifications

Pro-Tip: Apply a few drops of cutting fluid or wax lubricant when drilling steel electrical boxes to reduce thermal buildup and maximize the cutting edge sharpness of all 15 steps.