Century Drill Tool 74105 Lh Cobalt Stub Drill Bit Set 5pc

Product Description

The CENTURY DRILL TOOL CO INC 74105 is a 5-piece left hand cobalt stub drill bit set built for removing broken fasteners, extracting stripped screws, and reverse-drilling applications where standard right-hand bits are not effective. The set includes five sizes: 1/8 inch, 3/16 inch, 1/4 inch, 5/16 inch, and 3/8 inch. Each bit features a 135-degree split point for accurate starting without a center punch and a polished industrial finish. The stubby mechanics length provides increased rigidity compared to jobber-length bits, reducing deflection and improving control in tight access areas. These are cobalt steel construction throughout, not just a cobalt surface coating.

This set is suited for automotive, mechanical, and industrial work where left-hand rotation drilling is required. Common applications include extracting broken bolts, damaged studs, and seized fasteners on engines, exhaust systems, and machinery. The shorter stub length makes these practical in drill presses, lathes, and confined spaces where a full-length bit would be difficult to manage. Machinists, automotive technicians, and maintenance professionals will find this set covers the most common fractional sizes needed for fastener extraction work.

Key Features

• Left-hand flute geometry for reverse-rotation drilling and broken fastener extraction
• 135-degree split point starts on contact without center punching
• Stubby mechanics length increases rigidity and reduces deflection
• Cobalt steel construction resists heat buildup during hard-material drilling
• Industrial polished finish on all five bits
• Five-piece set covers 1/8 inch through 3/8 inch in fractional increments

Compatibility

Designed for use in any standard drill chuck or drill press accepting 1/8 inch through 3/8 inch shank sizes. Suitable for use with screw extractors and broken bolt removal kits as a companion left-hand drilling step.

Installation Notes

Left-hand drill bits are installed and operated with the drill set to reverse rotation. Secure the workpiece firmly before drilling to prevent movement. Use cutting fluid when drilling hardened steel or cast iron to extend bit life and reduce heat. Always wear appropriate eye protection when drilling.