Drill America 1-3/16" Reduced-Shank HSS Drill Bit, 1/2" Shank — 118° Point, Black Oxide

The Drill America DWDRSD1-3/16 is a 1-3/16" reduced-shank high-speed steel drill bit with a 1/2" shank, precision-ground 118° point, and black oxide finish for reliable drilling in low to medium tensile materials.

This reduced-shank bit lets larger diameters fit in portable chucks by reducing the shank to a standard 1/2" size, so you can use a wider range of bits without changing tooling. Constructed from high-speed steel and ground for concentricity, the DWDRSD series balances toughness and accuracy for general-purpose shop and field work. Its black oxide coating improves lubricity and helps retain coolant at the cutting edge, extending tool life under typical drilling conditions.

Why choose a reduced-shank drill bit for my portable drill?

A reduced-shank bit like this one lets you run a large cutting diameter in a standard-size chuck that otherwise couldn't accept the full body diameter. That removes the need for special adapters or larger drills when you only have a standard portable machine. The precision ground shank maintains concentricity so the bit runs true and minimizes wobble.

• Fits 1/2" chucks while providing a 1-3/16" cutting diameter
• Precision ground for improved runout and accuracy
• Works with common portable drills — no special collet required
• Black oxide helps hold lubricant and reduce friction during cutting

What materials is this HSS drill bit best for?

The DWDRSD1-3/16 is intended for low-to-medium tensile strength materials where high-speed steel performs well. Use it on mild steel, aluminum, plastics, and similar substrates where toughness and wear resistance from HSS are appropriate. Avoid hardened steel or abrasive composites where carbide or coated specialty bits are preferable.

• Recommended for mild steel and low-alloy steels
• Suitable for aluminum, brass, and many plastics
• Not designed for hardened steels or abrasive materials
• 118° point eases centering and reduces wandering on flat surfaces

How does the black oxide finish and 118° point help performance?

The black oxide treatment provides a modest increase in surface lubricity and creates micro-pockets that help retain coolant near the cutting edge. This reduces heat buildup and can improve chip evacuation during longer holes. The 118° split point geometry offers a general-purpose cutting angle that centers well and slices cleanly through common workpiece materials.

• Black oxide improves lubricant retention and reduces friction
• 118° point offers reliable centering without pilot holes in most materials
• Flute geometry evacuates chips when run at recommended speeds
• Round reduced shank simplifies tool changes between machines

What features affect accuracy and tool life?

This bit is precision ground to minimize runout between the shank and body, which keeps holes round and concentric. Common flute and overall lengths mean you can swap bits with little adjustment to set depth stops or tooling setups. Durable HSS combined with the finish balances wear resistance and toughness across a variety of general-purpose drilling tasks.

• Precision grinding reduces wobble and improves hole quality
• Consistent flute and overall length for predictable setups
• High-speed steel resists wear while maintaining toughness
• Round shank fits many toolholders and chucks securely

Who this is for: The Drill America DWDRSD1-3/16 is aimed at mechanics, fabricators, maintenance technicians, and DIYers who need the flexibility to run larger-diameter holes using a standard 1/2" chuck. It’s a good choice when you want dependable general-purpose drilling performance in low to medium tensile materials without investing in larger drills or specialty tooling.