12pcs 3/8 in M35 Cobalt Drill Bits - Durable Metal & Stainless Steel

In this review of the 12pcs 3/8 in cobalt drill bits from Pro Edge Technology, the bottom line is straightforward: this set is for users who need a cost-effective supply of tough, heat-resistant bits for drilling hard metals. The biggest reason to buy is the M35 cobalt composition that holds hardness at high temperatures, making these bits reliable for repeated work in stainless steel, cast iron and other demanding materials. This review looks at performance, materials and real user notes to help decide if the set fits a shop or serious DIY needs.

Key Features

• Quantity: Twelve 3/8 in bits provide a practical pack that meets extended cutting needs without constant reordering.
• Material: Made from M35 cobalt high-speed steel with about 5% cobalt for improved wear resistance and hot hardness.
• Heat treatment: Hardened to a high Rockwell range so the bits retain cutting edge and resist wear during hot, high-speed drilling.
• Tip design: 135-degree split point tip helps the bit self-center, reduces walking and improves drilling accuracy in metal.
• Versatility: Suitable for metal, stainless steel, cast iron, wood and plastic so the set covers common industrial and shop tasks.
• Compatibility: Standard jobber geometry fits any standard drill for straightforward use in hand drills and drill presses.

Who It's For

This set is best for mechanics, fabricators and serious DIYers who frequently drill hard materials and want a supply of robust 3/8 in bits without paying a premium for individual specialty sizes. The M35 composition and split point tip make them a practical choice where heat and wear are concerns.

Those who only drill soft materials occasionally or who require ultra-long-life carbide tooling for production volumes should look elsewhere; the bits perform well for heavy use but are jobber-length cobalt bits intended for general shop work rather than dedicated production carbide tooling.

Pros & Cons

Pros

• High-temperature hardness from M35 cobalt keeps edges firmer under heat compared with ordinary HSS.
• 135-degree split point reduces walking and improves centering for cleaner holes in stainless steel and alloy steel.
• A twelve-piece pack delivers good value and reduces downtime from replacing bits frequently.
• Suitable across materials including metal, wood and plastic for flexible use in the shop.

Cons

• Some users report the bits can dull with heavy use, so coolant and careful feed rates are recommended to extend life.
• As jobber-length bits, they are not optimized for deep-hole drilling or specialized carbide performance in high-volume production.

Specifications

Brand	Pro Edge Technology
Material	M35 cobalt high-speed steel (approx. 5% cobalt)
Size	3/8 in (diameter)
Quantity	12 pieces
Tip	135-degree split point
Applications	Stainless steel, alloy steel, cast iron, wood, plastic

Our Verdict

The 12pcs 3/8 in M35 cobalt drill bit set is a sensible buy for workshops that need durable bits for hard metals without overspending. With heat-resistant M35 steel and a self-centering split point, the set balances performance and value for maintenance shops, hobbyists and light industrial use; proper cooling and feed rates will help avoid premature dulling.

Frequently Asked Questions

Are these suitable for stainless steel?
Yes. The M35 cobalt composition and 135-degree split point make them effective for drilling stainless steel when used with appropriate coolant.

Do they fit standard drills?
Yes. These are jobber-style bits compatible with any standard drill chuck.

How can I extend bit life?
Use coolant or cutting fluid, moderate the feed rate, and check wear regularly; replace bits that show excessive dulling.