Chicago-latrobe 50913 Cobalt Screw Machine Drill Bit 0.042 in

Product Description

The CHICAGO-LATROBE 50913 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials including cast iron and steel. Built to Series 559 specifications, it features a 135-degree split point and web-thinned construction that reduces walking and cutting force on entry. The bit measures 0.042 inches in diameter (Wire Size 58) with an overall length of 1.375 inches and a flute length of 0.5 inches. Two spiral flutes clear chips efficiently during short-hole operations. Right-hand cutting direction and a straight cylindrical shank make it compatible with standard drill chucks. This is a heavy-duty grade M42 cobalt bit suited for production and maintenance machining environments.

Screw machine length drill bits are shorter than jobber-length bits, providing greater rigidity and reduced deflection in CNC machining centers, turret lathes, screw machines, and drill presses. The 50913 is particularly well-suited for drilling cast iron and steel workpieces where heat buildup and wear resistance are primary concerns. M42 cobalt construction retains hardness at elevated cutting temperatures, extending tool life compared to standard high-speed steel bits. Machinists, tool-and-die technicians, and maintenance mechanics working in metalworking and fabrication shops will find this bit appropriate for close-tolerance, repetitive drilling tasks.

Key Features

• M42 cobalt construction for heat resistance and extended tool life in ferrous metals
• 135-degree split point reduces thrust force and eliminates center punch requirement
• Web-thinned, parallel web design lowers cutting resistance on entry
• Screw machine length body provides added rigidity and reduced deflection versus jobber bits
• Right-hand spiral flutes promote efficient chip evacuation in blind and through holes
• Diameter tolerance held to +0.0000 to -0.0005 inches for consistent fitment

Compatibility

Designed for use in standard drill chucks accepting straight cylindrical shanks. Primary workpiece materials are cast iron and steel. Suitable for use in CNC machining centers, turret lathes, screw machines, and manual drill presses where screw machine length tooling is specified.

Installation Notes

Secure the shank fully in the drill chuck and verify runout before beginning a drilling cycle. Small-diameter cobalt bits are brittle under lateral load — avoid side pressure and use appropriate feed rates for the workpiece material. Coolant or cutting fluid is recommended when drilling steel to extend bit life, though this bit is not rated for coolant-through delivery. Follow shop safety protocols and applicable OSHA standards when operating rotary cutting tools.