Screw Extractor

How do I get a broken screw out again? Our recommendation: please use a left-hand screw extractor. The left-hand extractor, also called screw extractor, is used when the screw head is defective and the original extracting tool (screwdriver, Allen key) no longer grips and can therefore no longer be used.

Construction of a screw extractor

The screw extractor has a square according to DIN 10, a cylindrical shaft and a rolled tapered extracting part (precision taper thread), which can be shaped differently depending on the extracting type. In any case, this taper thread has a left-hand twist. The tool is hardened. The square is used for holding in an adjustable tap wrench or a tool holder.

Instructions for the use of a screw extractor

How does a left-hand screw extractor work? The basic idea is as follows: A small hole is drilled into the screw to be loosened so that the precision taper thread can grip there. However, the hole must not be set at an angle or even predrilled too large. The thread of the screw can then be spread. This will considerably worsen the initial situation. Therefore, observe the information in the following table exactly and do not drill too large or too deep. 

One more tip on the use of the left-hand boring tool:

Often the heads of the screw are torn out because the screw has "seized" or rusted. Our tip in this case: penetrating oil. This so-called penetrating oil infiltrates rust layers and dirt. The oil can thus help to loosen rusted screws and thus facilitate unscrewing to prevent the screw extractor from breaking off. 

It's best to buy a screw extractor set. That you are well equipped for all incidents.

How do I use screw extractors on rusted screws?

Which screw extractor should I use?

Video Tutorial: Screw extractor - The correct use