Chicago-latrobe 49010 Screw Machine Drill Bit 4.20 Mm Cobalt

Product Description

The CHICAGO-LATROBE 49010 is a screw machine length (stub length) cobalt drill bit designed for high-production drilling in tough ferrous materials. Built to DIN 1897 standards and produced in M42 cobalt high-speed steel, it measures 4.20 mm (0.1654 inches) in diameter with an overall length of 57.02 mm (2.245 inches). The 135-degree split point self-centers on contact and reduces thrust, making it well suited for hard materials where a standard 118-degree point would walk or wear prematurely. A straw oxide coating provides additional lubricity and heat resistance during cutting.

This bit is intended for production drilling in tool steel, alloyed steel, carbon steel, and cast iron. The stub-length body limits deflection and increases rigidity compared to jobber-length bits, making it a preferred choice for drill press work, CNC machining, and manual spindle operations where hole location accuracy and bit life matter. Maximum drilling depth is 0.5789 inches, consistent with screw machine length applications in sheet stock, plate, and short-depth through-holes.

Key Features

• M42 cobalt high-speed steel construction for extended tool life in hard and abrasive materials
• 135-degree split point self-centers and reduces walking on entry without a center punch
• Straw oxide coating adds lubricity and surface hardness
• Stub-length body increases rigidity and reduces deflection in close-tolerance work
• Right-hand cut, regular spiral flute design for standard CW spindle operation
• Built to DIN 1897 specification with diameter tolerance of +0.0000 to -0.0007 inches

Compatibility

Designed for drilling tool steel, alloyed steel, carbon steel, and cast iron. Compatible with any standard drill press, CNC machining center, or hand drill with a chuck accepting a 4.20 mm straight cylindrical shank.

Installation Notes

Secure the workpiece firmly before drilling and confirm the spindle speed is appropriate for the material and bit diameter. Always power down and de-energize the machine before changing bits or adjusting chuck position. Use cutting fluid or coolant when drilling deep into hard steel to manage heat buildup, as this bit does not support coolant-through delivery. Inspect the split point and cutting edges for chipping or wear before each use; cobalt bits subjected to overheating may lose temper and should be replaced.