Allen Keys ,Torx And hex Bolts

Allen and Torx bolts are female fittings where the tool goes into the bolt rather than over it. That leads to particular problems you need to be aware of.

1) Always make sure the recess is clear of mud, corrosion and debris. Have a good scrape round inside with a small screwdriver before fitting the allen key.

2) Make sure the allen key is fully engaged. It's much harder to be sure an allen key is fully inside its bolt than it is to be sure a socket is fully over a hex bolt where you can see what is going on. If you try to undo a stuck allen bolt and the key is only partly engaged then you'll round off the bolt or the key. Make sure the recess is clear then tap the key in with a hammer.

3) Allen keys get worn at the ends after much use. Grind the key shorter to remove the rounded ends and expose new sharp edges or buy new ones if yours are looking worse for wear. Use top quality allen keys. Unbrako is a good name.

4) If the bolt is starting to round off then you can hammer an oversize key in. A 1/4" key will normally remove a worn 6mm bolt. A 10mm key will remove a worn 3/8" one.

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