AMOOLO Cobalt Drill Bit Set 31Pcs 1/16in-1/2in - M35 High Speed Steel

In this review the AMOOLO Cobalt Drill Bit Set 31Pcs is evaluated for metalworkers and hobbyists who need a wide range of sizes in a single kit. The set stands out because it uses M35 cobalt high speed steel with 5% cobalt, which delivers greater wear resistance and hotter-cutting capability than standard HSS bits; that is the single biggest reason a buyer focused on drilling hardened metal should consider it. The kit's jobber length assortment and plastic case make it a practical choice for shop or garage use, though users should mind speed and heat control when drilling tough alloys.

Key Features

• M35 cobalt steel: The 5% cobalt content increases heat resistance and hardness for longer life when cutting stainless steel and hardened metals.
• Wide size range: Thirty-one jobber length bits cover common sizes from 1/16in to 1/2in, letting the user avoid frequent trips to buy a single size.
• Split point design: The 135 split point reduces walking so holes start cleanly without a center punch in most cases.
• Spiral flute geometry: Fully ground spiral grooves evacuate chips quickly and reduce friction and heat during drilling.
• Compact storage case: The portable plastic case keeps bits organized and easy to transport between jobs or around the shop.

Who It's For

This set is best for DIYers, metal fabricators and mechanics who frequently drill into stainless steel, steel, cast iron and other harder metals and want a broad selection of sizes without buying individual bits. It is also useful for any workshop that needs reliable jobber length bits for general purpose cutting through aluminum, plastic and wood.

Those who primarily drill very thin sheet metal or need extreme precision on delicate parts may want a different specialty bit or a smaller-diameter premium bit; similarly, heavy production shops that demand maximum tool life under continuous high-volume use might prefer industrial-bonded or coated tool bits designed for CNC or high-feed applications.

Pros & Cons

Pros

• Good value: offers 31 sizes and a storage case for a price that compares well with pricier cobalt sets.
• Effective on hard metals: M35 composition and split point produce clean starts and cut through stainless and mild steel well.
• Fast chip evacuation: fully ground spiral flutes reduce heat buildup for cooler drilling.

Cons

• Mixed durability reports: some users report breakage when pushing through very thin tough sheet metal, so careful feed and speed control are important.

Specifications

Our Verdict

The AMOOLO 31-piece M35 cobalt set is a solid, cost-effective kit for hobbyists and small shops that need a full range of jobber length sizes and the ability to cut harder metals. It delivers strong drilling performance thanks to its M35 cobalt construction and split point design, though users should control speed and pressure to avoid breakage on thin gauge steel. Overall it represents good value for those who want versatile, durable bits without buying singles.

Frequently Asked Questions

Can these bits drill stainless steel?
Yes. The M35 cobalt composition and 135 split point make them suitable for drilling stainless steel with proper speed and coolant where needed.

Do I need a center punch with these bits?
Usually not; the 135 split point helps prevent walking so a center punch is often unnecessary for general work.

What sizes are included?
The set includes 31 jobber length sizes covering commonly used diameters from 1/16in through 1/2in stored in a plastic case.