Screw extractors can be driven by either manual or power tools.
Adjustable spanners
An adjustable spanner is a spanner with an adjustable ‘jaw’ which allows the tool to be used with different sizes of fastener heads such as nut, bolts, etc.
The knurled adjustable screw is used to change the jaw width.
The size of an adjustable spanner refers to the maximum jaw width. These are:
5/16 – 8mm
3/8 – 10mm
7/16 – 11mm
1/2 – 13mm
9/16 – 14mm
5/8 – 16mm
11/16 – 17mm
3/4 – 19mm
Tap wrenches
There are two main types of tap wrench: bar type (double-end) and T-handle.
T-handle design
A tap wrench is used by hand to turn taps or other small tools such as screw extractors. The T-handle tap wrench uses a chuck to secure the tool by forming a clamp around the object to hold it in place.
Because of it’s lengthy design, it’s useful in confined spaces or where extra reach is needed.
T-handle tap wrenches have a chuck width of:
1.5 – 3mm
2 – 5mm
2.5 – 5mm
4 – 6.8mm
4.6 – 8mm
8 – 12mm
Bar-type design
A bar type (double-end) tap wrench has a threaded handle which is attached to one of the clamps and is used to open and close it.
The tool is inserted and secured against the tool, using the handle.
Bar type tap wrenches have a clamp width of:
2.50 – 12mm
4.25 – 14.4mm
4.25 – 17.7mm
6.80 – 23.2mm
M4 – M8 – 4 – 8mm thread
M4 – M14 – 4 – 14mm thread
M7 – M27 – 7 – 27mm thread
Drills
Some screw extractors can be used in drills. The extractor is held securely in the drill’s chuck and rotated whilst being pressed against the target material.
Screw extractors have an end diameter of 10mm (3/8” approx.), so will require a chuck with the same capacity in order for them to be used.
Mole grip pliers
Mole grip pliers are hand tools that can be locked into position in order to turn the extractor or remover manually.