Hi Martyn tab washers are there to prevent a nut or similar unscrewing and if they are too soft they would not do their job or may break if hardened wrongly. I don't know the results of a nut coming undone have you thought of wireing the nuts instead it can be easier to access and does the same job.

David

Don't make them from aluminium; the tab will break off too easily. Cut them out of sheet steel with tin snips. 1mm thick should do the job but a bit thicker would be better. Machining a bar and cutting slices as you suggest would have the grain of the metal going the wrong way and be very weak and prone to tab snapping off.

I can't visualize your exact application without pic but one trick is to slightly bend the tab up a little (30 – 45 deg?) before installation so you can then get a screwdriver or plier jaw in behind it when installed in situ.

The best method to bend up the tab, if there is access, is to use a pair of slip joint pliers (aka multi-grips, parrot nose pliers or water pump pliers depending on side of the pond etc) with one jaw on the far side of the nut and one on the tab, with the the pliers oriented so the longitudinal axis of the plier jaws is in line with the longitudinal axis of the bolt. You then use a levering action on the pliers rather than a squeezing one to bend the tab up.

I suppose for tiny model size stuff you could use fine long nose pliers in the same way.

And you won't soften steel tabs by quenching. Heat to cherry red and allow to cool slowly to anneal. But I really don't think that is your problem. There is no reason a lock tag would be particularly hard other than perhaps an insignificant area on the very edge where it was punched out of flat sheet.

Edited By Hopper on 07/04/2019 02:28:30

Edited By Hopper on 07/04/2019 02:32:18

You don't want to quench anything to make it easier to bend. Heat to red heat and then allow to cool slowly, job done.

I get them laser cut on a tree and break them off.