Square screw extractors feature four sided sharp undercut edges to provide a solid grip and will not expand damaged fastener during extraction.
They are ideally suited for removing broken bolts, studs & socket screws from medium to hard metals.
Typically the required screw extractor will be approx. 2/3 the diameter of the fixing you are extracting.
Use a centre punch to mark the centre of the fixing before drilling to prevent the drill bit wandering.
Select a drill bit that is suitable for drilling into the specific material - typically HSS or HSS-Co5. Ideally the drill should be “Left Hand" which will prevent further tightening of the fixing during drilling.
When using left hand drills ENSURE THE DRILL IS SET TO REVERSE.
Drill pilot hole in centre of broken bolt, screw or stud.
Lightly tap screw extractor into hole and turn anti-clockwise with a tap wrench or spanner.
Damaged bolt, screw or stud will unwind out of the hole.
Avoid excessive lateral loads - breakage could result.
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