1/4in (6.35mm) Left Hand Drill Bit Carded – Cobalt Series

• For the removal of damaged bolts (stud) and screws 
• 8% cobalt 

Technical data:

• Diametre: 1/4″, 6.35mm 
• Overall length: 64mm
• Flute length: 34mm 

Directions for use: 

1. If possible, grind or flatten the head of the damaged bolt or screw.

2. Use a heavy hammer and centre punch to mark the centre of the bolt or screw. This will prevent the drill from wandering.

3. Drill into the bolt or screw in reverse using a small size left-hand drill with a variable speed reversible drill.

4. If the bolt does not reverse out, use the small hole as a pilot hole and change to a larger size left-hand drill. Most bolts come out before the hole drilling operation is finished.

5. The drill will grab the bolt when breaking through the backside. Typically, this is the stage when the broken fastener will spin out of the threaded hole. When drilling through the broken bolt, vibration will help to break the bolt free.

Note: If this drilling operation has not removed the broken stud or bolt, the hole drilled will form a pilot hole for a screw extractor.