MACXCOIP 5/16 in Cobalt Drill Bit Set — 10pc M35 HSS Jobber-Length, 135° Split-Point

MACXCOIP 5/16" M35 cobalt drill bit set (10 pieces) is a jobber-length HSS kit engineered for reliable drilling in hard metals and general workshop use.

This compact pack contains ten identical 5/16" (approx. 7.94 mm) jobber-length bits forged from M35 high-speed steel with cobalt alloying for extra heat resistance and toughness. Designed with a 135° split-point tip and a conventional twist flute, these bits balance aggressive cutting with improved centering and chip evacuation, making them a practical choice for stainless steel, cast iron, aluminum, copper and common workshop materials, as well as wood and plastics when needed.

How do these M35 cobalt bits perform on stainless steel and other hard metals?

The M35 composition adds 5% cobalt to HSS, boosting hardness at high temperatures so the bits maintain cutting edges longer when machining hard metals. The 135° tip reduces walking at startup, and the jobber length provides reach without excessive flex for most bench and hand drilling tasks.

• Material: M35 HSS with cobalt for elevated heat resistance and wear life
• Tip geometry: 135° split-point for self-centering and reduced skidding
• Length: jobber length for a balance of reach and rigidity
• Applications: stainless steel, cast iron, aluminum, copper, plastics, wood

What makes this 10-piece single-size set useful for workshops and professionals?

Supplying ten identical 5/16" bits eliminates the need to swap sizes repeatedly during a repeat-drill job, saving time on production runs and maintenance tasks. The uniformity is useful for fabricators, mechanics, and tradespeople who frequently drill the same diameter for fasteners or dowels.

• Quantity: 10 identical 5/16" bits for repetitive drilling jobs
• Packaging: compact, sturdy case for organized storage and transport
• Consistency: identical geometry across the set for repeatable hole quality
• Compatibility: fits standard drill chucks and drill presses

How should I use and maintain these cobalt jobber drills for best life?

Use moderate feed rates and appropriate cutting speeds for the metal you're drilling; cobalt HSS tolerates higher speeds but still benefits from cooling or pecking when cutting thick or stainless workpieces. Keep flutes clear of chips and store the set in its case to avoid nicking tips during transport.

• Drill speed: adjust lower for stainless steel, higher for softer metals
• Cooling: apply cutting fluid or use pecking cycles for long holes
• Chip clearance: clear chips frequently to prevent heat buildup
• Storage: keep bits in the provided case to protect cutting edges

What size and tool compatibility should I expect from this 5/16" set?

Each bit measures 5/16" (imperial) jobber length and is compatible with standard three-jaw chucks found on drills and drill presses. The single-size format simplifies tooling choices when your project consistently requires that diameter.

• Diameter: 5/16" (approx. 7.94 mm)
• Length: jobber length for general-purpose use
• Chuck fit: usable in standard keyed and keyless chucks
• Suitability: ideal for pilot holes, bolt/fastener holes, and general fabrication

Who is this for? This MACXCOIP M35 5/16" 10-piece set is aimed at hobbyists, metalworkers, maintenance technicians and professionals who need a reliable single-diameter solution for repetitive drilling in metals and general materials. If you routinely drill 5/16" holes in tougher alloys or want a robust backup set for a busy shop, this kit provides durable cutting edges, consistent hole quality and convenient storage.