amoolo 5/16-inch Cobalt Drill Bit Set - 10 pcs, M35 HSS for Hard Metals

Durable, versatile drill bits for hard metals

Meet the amoolo 5/16-inch cobalt drill bit set, a compact collection designed to handle tough materials with precision. Each bit features a robust M35 cobalt alloy and a straight shank, ensuring compatibility with a wide range of power drills you already own. The 3-inch flute length helps chip removal and smoother progress, letting you tackle stainless steel, cast iron, and other hard metals with more control and confidence.

Crafted for reliable performance, this 10-piece bundle blends hard-wearing construction with thoughtful geometry. The 135-degree split point reduces wandering at start, providing a clean, accurate entry point. Fully ground with a spiral groove design helps clear particles quickly, reducing heat and friction for more consistent drilling under demanding conditions.

Not just for metal, these bits also tackle plastics, aluminum alloys, and softer materials when you adjust speed and feed. From workshop projects to professional tasks, you’ll notice that material choice and drilling approach matter. Use steady pressure, moderate speed, and adequate lubrication to optimize results and extend tool life.

What you get

• Ten 5/16-inch cobalt drill bits with durable M35 high speed steel construction
• Fully ground tips with 135° split points for starting accuracy
• Spiral grooves designed for efficient chip evacuation and cooler operation
• Straight shank for broad compatibility with most power drills
• Boxed packaging keeps all pieces organized for easy storage

Key benefits and suitability

• Enhanced wear resistance makes these bits well suited to stainless steel and other hard metals
• 135° split point helps you start cleanly without center punching
• Effective debris clearance supports smoother drilling and cooler operation
• Versatile enough for plastics, aluminum, and wood with appropriate parameters

Usage tips and care

• Drill at moderate speed with steady, controlled pressure; avoid excessive heat
• Use cutting oil or coolant when drilling metals to extend bit life
• Inspect bits for wear and replace if edge integrity declines

Warranty

Enjoy peace of mind with a 90-day warranty offering refund or replacement if you’re not fully satisfied.