Precision Twist Drill 5995960 M40CO 3/4 in Cobalt Screw Machine Length Drill Bit 135° Split Point

The Precision Twist Drill M40CO 5995960 is a 3/4 inch (0.750 in) heavy-duty screw machine length drill bit engineered for demanding applications in hard and abrasive materials. Built from high-speed cobalt steel (HSS-E) with a distinctive bronze (gold) oxide finish, this drill bit delivers superior heat and wear resistance compared to standard HSS tooling.

Key Features:

• Series: M40CO — Heavy-Duty Screw Machine (Stub) Length
• Drill Size: 3/4 in (0.750 in) fractional
• Point Angle: 135° split point / self-centering for fast starts without center-punching
• Construction: High-Speed Cobalt Steel (HSS-E) for extended tool life in tough materials
• Finish: Bronze (gold) oxide — a low-temperature heat treatment that reduces grinding stress and identifies cobalt tooling
• Flute Style: Type N spiral flute (regular helix, 21°–34°) for efficient chip evacuation
• Shank: Straight round shank, diameter matching drill size
• Cutting Depth: Up to 2.5× the drill diameter
• Cut Direction: Right-hand cutting

Recommended Materials:

• Hardened and tempered alloy steel
• Stainless steel (free-machining, ferritic, austenitic, martensitic)
• Nodular graphite and malleable cast iron
• Titanium and nickel alloys
• Plain carbon and structural steel

The shorter screw machine (stub) length provides increased rigidity and reduced deflection, making the M40CO ideal for precision drilling in CNC machining centers, drill presses, and production environments. Also known as: PTD 046048, DORM40CO3/4.