Century Drill & Tool 24220 — 5/16-inch x 4-1/2-inch black oxide drill bit, made from high-speed steel and designed for jobber length applications:

Key Features

• High-Speed Steel (HSS):
  • Durable and heat-resistant
  • Suitable for repeated use
• Black Oxide Finish:
  • Enhances wear resistance
  • Retains lubricants for smoother drilling
  • Offers up to 6–8x longer life than standard 118° bits 
• 135° Quick-Cut Point:
  • Self-centering for precise starts
  • Reduces pressure needed to drill
• Jobber Length:
  • Standard length for handheld drills and drill presses

Specifications

• Size: 5/16 inch (Decimal Equivalent: 0.313 inch)
• Overall Length: 4-1/2 inches (114.3 mm)
• Material: Industrial-grade high-speed steel (HSS)
• Finish: Black oxide
• Point Angle: 135° Quick-Cut Point
• Shank Type: Straight
• Flute Type: Quick Cut
• Standard: Aerospace NAS 907-B
• Made in: USA

Applications

This drill bit is designed for general-purpose drilling in:

• Metals:
  • Mild steel
  • Flat bar
  • Angle iron
  • Tubing
• Wood:
  • Softwood and hardwood
• Plastics:
  • PVC
  • Acrylic
  • Polycarbonate

No center punch needed — the Quick-Cut Point is self-centering and penetrates faster with less pressure, preventing walking or wandering on the surface.