Four Spiral Flute M35 Step Drill Bit Set 1/8ft - 1ft (9 Sizes)

In this review the Four Spiral Flute M35 Step Drill Bit Set is evaluated as a tool-oriented solution for anyone who regularly drills metal, plastic, or wood and needs quick, varied hole sizes without frequent bit changes. The bottom line: this set is for DIYers and professional tradespeople who want durable, cobalt-enhanced step bits that cut smoothly through stainless steel and other materials, with the primary advantage being the M35 cobalt construction and four-spiral groove design that improves cutting speed and wear resistance.

Key Features

• M35 Cobalt Superhard Steel: Provides high wear resistance and pressure tolerance for extended life when drilling harder materials such as stainless steel.
• Four Spiral Groove: The four cutting blade design helps evacuate chips faster and delivers smoother, faster cutting compared with common two-flute step bits.
• Wide Size Range: The 9-size stepped profile covers hole diameters from 1/2' to 1', letting users create multiple hole sizes with a single bit.
• TiAlN Coating: Industrial-grade coating improves hardness and thermal resistance so the bits keep sharpness longer under heavy use.
• Hex Shank and Compatibility: The 3/8' shank fits standard drill chucks and is compatible with Unibit-type step drilling for quick diameter changes.
• Customer Support Warranty: A long warranty promise and responsive support (reply within 12 hours) offers replacement or refund if the hex handle fails.

Who It's For

The set is best suited to mechanics, metal fabricators, HVAC technicians and serious DIYers who frequently drill through sheet metal, aluminum, plastic panels or thin stainless steel and need a durable bit that resists dulling. Its M35 cobalt construction and TiAlN coating make it a sensible choice when cordless high-speed drilling is used and longevity matters.

Less suitable users are casual hobbyists who only drill occasional soft-wood or very thin plastic, where a basic twist bit set would be more cost effective. Also avoid using the step bits on boards thicker than the height of the step profile, as they are designed for thinner panels and sheet materials.

Pros & Cons

Pros

• Excellent cutting sharpness and strength for stainless steel and other metals.
• Four-flute design speeds chip removal and improves drilling smoothness.
• Wide stepped size range reduces the need to swap bits for common hole diameters.

Cons

• Step height limits use on thicker boards, so it is not ideal for deep timber drilling.

Specifications

Our Verdict

The M35 Four Spiral Flute step drill set is a practical, long-lasting choice for professionals and dedicated DIYers who need a single bit to produce multiple hole sizes quickly and reliably, especially in stainless steel and sheet metals. Its cobalt alloy and TiAlN coating provide tangible durability and cutting performance, making it good value for repeated metal work where fewer bit changes and longer life matter.

Frequently Asked Questions

Can these drill stainless steel?
Yes. The M35 cobalt composition and four-flute design improve cutting speed and wear resistance for stainless steel and other hard metals.

What drills are compatible?
The bits fit standard 3/8' chucks and are intended for use with high-speed cordless drills and Unibit-style step drilling operations.

Are these suitable for thick wood?
They work on wood but are designed for thinner boards and sheet materials; thick timber may exceed the step height and is not the ideal use case.