Precision Twist Drill 5999837 Reduced Shank Drill Bit

Product Description

The PRECISION TWIST DRILL 5999837 is a reduced shank cobalt drill bit designed for drilling into ferrous metals and a wide range of secondary materials. The bit measures 55/64 inches (0.8594 inches decimal) in diameter with a 1/2-inch straight-cylindrical shank, allowing it to chuck into standard 1/2-inch capacity drill chucks even though the bit diameter exceeds that size. Overall length is 6 inches with a 3-inch flute length. The 118-degree split point reduces walking on entry and lowers thrust requirements, making it a practical choice for production and maintenance drilling in metal fabrication, mechanical, and HVAC service environments.

This bit is well suited for drilling ferrous metals including steel and iron, and is rated for secondary materials such as aluminum, copper, nickel, titanium, magnesium, and synthetic materials. The Series R56CO reduced shank design fits standard 1/2-inch drill chucks, making it compatible with common corded drills, drill presses, and magnetic base drills used in trade and light industrial settings. The right-hand spiral flute configuration handles the full 3-inch maximum drilling depth the flute length allows.

Key Features

• 55/64 inch diameter (0.8594 inches decimal) with 1/2-inch reduced straight-cylindrical shank
• Cobalt tool material for heat resistance and extended tool life in ferrous metals
• 118-degree split point for reduced walking and lower entry thrust
• 3-inch flute length supports up to 3 inches maximum drilling depth
• Bright/uncoated finish — no coating to flake or chip in high-heat applications
• Right-hand cut, regular spiral flute — compatible with standard drill press and handheld drill setups
• Meets ANSI standards

Compatibility

Designed as an OEM-style replacement and direct-use drill bit for any application requiring a reduced shank cobalt bit in the 55/64-inch diameter range. Fits any 1/2-inch drill chuck. Primary workpiece material is ferrous metal; secondary workpiece materials include aluminum, cermet, copper, magnesium, nickel, synthetic, and titanium per manufacturer specifications.

Installation Notes

Install the reduced shank fully and evenly into a 1/2-inch drill chuck and tighten securely before operation. Power down and de-energize any drill press or magnetic base drill before changing bits. When drilling ferrous metals at this diameter, use appropriate work-holding fixtures and eye protection per applicable shop safety standards. Coolant is not required for this bit per manufacturer specifications, but chip clearing and feed rate management are important at larger diameters to avoid bit deflection or breakage.