Large Step Drill Bit for Steel 1-5/8in Pro - Heavy Duty M35 Cobalt

In this review the Large Step Drill Bit for Steel 1-5/8in Pro is judged as a specialist option for tradespeople and serious DIYers who need a single, heavy duty step bit that tackles thick metal. The bottom line: this is a purpose-built, extra-heavy duty M35 cobalt step bit that excels when drilling a range of hole sizes in stainless steel and other hard metals, offering long wear and fast cutting for sheet and plate work where a standard HSS bit struggles.

Key Features

• Large 13-step range: the bit covers incremental sizes from 3/16in up to 1-5/8in so a single tool handles many hole diameters without swapping bits.
• M35 cobalt steel: the 7% cobalt alloy is designed for extra hardness and heat resistance, giving longer life when cutting stainless and other hard metals.
• Extra-heavy duty design: the thick stepped profile and spiral flutes are built to clear chips fast and resist grabbing when cutting through plate and tubing.
• 3/8in tri-flat shank: the tri-shank reduces slippage in the chuck for high-torque drilling and better control on larger holes.
• Two-spiral flute: flutes are shaped to evacuate chips quickly, improving feed and reducing heat buildup on continuous cuts.
• Broad material compatibility: suitable for stainless steel, galvanized steel, aluminum, wood, PVC and copper for versatile shop and field use.

Who It's For

This bit is aimed at metalworkers, fabricators, landscapers, agricultural maintenance crews and anyone who frequently drills through stainless plate, cold-rolled steel or heavy sheet metal. It is a good fit when you need many hole sizes quickly without changing bits, such as when fitting grommets, mounting hardware or enlarging holes in metal panels.

Those who should look elsewhere include casual users who only drill small holes occasionally with a cordless driver, or people who need extremely long-term edge retention for high-production CNC work; in those cases dedicated solid carbide tooling or job-specific twist bits may be a better match.

Pros & Cons

Pros

• Durable M35 cobalt construction for improved life and cutting speed on hard metals.
• Wide 13-step diameter range eliminates multiple bit changes for many common hole sizes.
• Tri-flat shank and spiral flutes provide positive grip and efficient chip clearing during heavy work.
• Versatile across metals, plastics and wood for mixed-job sites.

Cons

• Some users report mixed results on very aggressive structural purlins; technique and feed control matter.
• Because it is large and heavy duty, it requires a powerful drill and steady setup for best results.

Specifications

Material	M35 cobalt steel (about 7% cobalt)
Size range	13 steps: 3/16in to 1-5/8in
Shank	3/8in tri-flat shank
Flute type	2-spiral-flute for faster chip clearing
Intended use	Stainless steel, hard metal, aluminum, wood, PVC, copper
Grade	Industrial extra-heavy duty

Our Verdict

The Large Step Drill Bit 1-5/8in Pro is a sensible buy for professionals and serious DIYers who need a single, durable step bit to handle multiple hole sizes in stainless and other hard metals. Its M35 cobalt build and chip-clearing flutes deliver good value where fewer bit changes and robust cutting are priorities, though it benefits from a strong drill and correct feed technique.

Frequently Asked Questions

Will this bit cut stainless steel?
Yes. The M35 cobalt composition and heavy-duty geometry make it suitable for stainless sheet and plate when used with steady feed and proper speeds.

What drill is needed?
A high-torque drill or drill press is recommended to maintain control and avoid breakage when cutting larger diameters with this heavy step bit.

What sizes does it cover?
The bit covers 13 steps from 3/16in up to 1-5/8in, allowing many hole sizes without changing bits.