File buttons

[thehomeengineer]

Hi All
This is a method I use whenever possible as it is quick easy and accurate to file a radius on a component. I have a tin of these I have made over the last 30 years all types and sizes. Sometimes I get lucky and find a pair of buttons I have previously made. The photos below show the method taken to put two radius on a key. The holes in the end of the key are, drilled 3mm to be a close fit on the clamping bolt. Once the radius are, filed to shape, these holes will then, be opened up to 3.3mm and tapped M4. The reason for this is, if I ever need to remove the key, I can use these M4 threads as jacking points.

Turning and drilling silver steel rod


Parted off and faced both end square



Heating the silver steel to harden, I do not bother tempering as I feel there is no need.


The harden buttons, are clamped in place with a M3 socket cap screw, which is a snug fit in the holes of both the key and the buttons (good engineering term lol)




Held in a vice and just file down until the file is in contact with the buttons.




Finished radius.


Key fitted with no additional fitting. Nice tight snug fit


Thank you for taking the time to view
The Home engineer