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+--- Thread: How strong is a 10 mm Hex Key ? (/thread-3993.html)
How strong is a 10 mm Hex Key ? - awemawson - 01-31-2019
Today I re-aligned the tool disk on the turret of my CNC lathe, which involved unscrewing eight 10 mm socket cap screws with a 10 mm hex key.
They were so tight, it wasn't until I added a four foot long tube as a 'torque amplifier' and my not inconsiderable mass that things started to move.
I must have been very close to the shear strength of the key. it was a good quality 'Unbrako' one, but what sort of torque will they take before bits go flying and knuckles get bruised ?
RE: How strong is a 10 mm Hex Key ? - awemawson - 01-31-2019
quick correction - those cap screw were 12 MM !!!!!
RE: How strong is a 10 mm Hex Key ? - TomG - 01-31-2019
Good question Andrew. There are torque ratings for the cap screws themselves around 160 foot pounds for a 1/2" screw, but not much on the key itself, and those ratings are for the working strength, not ultimate strength. I suspect the screw itself would fail before the hex key.
Tom