Four Spiral Flute Cobalt Step Drill Bit Set Pro Max - Smooth Metal

Our review of the Four Spiral Flute Cobalt Step Drill Bit Set Pro Max finds it best suited for metalworkers and serious DIYers who need fast, clean holes in thin metal and mixed materials. The single biggest reason to buy is the four spiral flute geometry combined with TiAlN coating and M35 cobalt construction, which together deliver noticeably quicker, smoother cutting through stainless steel, mild steel, aluminum, wood and plastic than typical twoflute step bits. This set feels engineered for repeated use at higher cutting speeds, especially on 1/8in to 3mm thick sheets.

Key Features

• Four spiral flute: Four cutting edges reduce vibration and produce a smoother bore so holes come out cleaner with less burr.
• TiAlN coating: A hard 89HRC surface finish lets the bits run at higher speeds and resist wear on tougher materials.
• M35 cobalt HSS: The cobalt high speed steel body maintains edge strength for drilling into stainless and mild steel sheets.
• 34 step sizes: A wide range from 1/8in to 7/8in covers most common hole sizes without swapping bits.
• 1/4in hex shank: The hex shank fits impact drivers and reduces slippage when driving through thicker metal.
• Warranty: The seller offers a refund or replacement and will replace a snapped hex shank, which adds purchase confidence.

Who It's For

This set is aimed at fabricators, metalworking hobbyists and contractors who frequently drill thin metal sheets and want faster, cleaner cuts than standard step bits provide. It performs well on stainless steel, mild steel, aluminum, copper, plastic and wood, making it a versatile choice for mixedmaterial projects.

Those who primarily drill heavy plate, large concrete anchors or need precision reaming at extremely tight tolerances should look elsewhere, as step bits are optimized for sheet work and rapid size changes rather than heavy structural drilling or finishing with reamers.

Pros & Cons

Pros

• Excellent cut quality and speed on thin stainless and mild steel thanks to the four flutes and cobalt HSS.
• Durable TiAlN coating increases surface hardness and allows higher operating speeds with less wear.
• Wide size range with 34 steps eliminates frequent bit changes for many common hole sizes.
• Hex shank is impactdriver ready and reduces bit slip during use.

Cons

• Some users report mixed durability; tips can chip if used aggressively or without proper feed and speed control.

Specifications

Brand	AugTouf
Material	M35 cobalt high speed steel (HSS)
Coating	TiAlN with approx 89HRC surface hardness
Step range	1/8in to 7/8in (34 step sizes)
Shank	1/4in hex shank, impact ready
Intended materials	Stainless steel, mild steel, aluminum, wood, plastic, copper
Warranty	100% refund or replacement; hex shank replacement available

Our Verdict

This Pro Max step drill bit set is a strong value for anyone who cuts thin metal and mixed materials frequently; the four spiral flutes and TiAlN coating translate to faster, cleaner holes and better heat resistance than standard step bits. It is a practical and versatile addition to a metalworker's kit, provided users respect proper speeds and feeds to avoid occasional tip damage.

Frequently Asked Questions

Can these bits cut stainless steel?
Yes, the M35 cobalt HSS and TiAlN coating are intended for cutting stainless steel sheet up to typical thin gauges like 1/8in or 3mm.

Will the bits work in an impact driver?
Yes, the 1/4in hex shank is designed to be impact ready and reduces slippage when used in drivers or impact drills.

What if a shank breaks?
The seller offers replacement for a snapped hex shank and a full refund or replacement if you are not satisfied, so contact customer support for warranty service.