rivet forming tools ?

[RichardT10829]

I had a chat with Martyn regarding making my own forms, i believe he used Moyle point chisels cut down and heated up and hammered over a ball bearing to create a cup. I was going to do similar but wondered if i harden a rivet first by heating it up then quenching in oil, let it cool and use it as a form. then heat the bar up form the end over the hardened rivet and again quench the bar in the oil..... as i say i was wondering if they could be puchased. all my top armour will be done so no worries about mix and match, plus all the rivets i have got are imperial the supplier can even do them countersunk all be it i will be using normal dome heads unless i find a way to countersink all my holes 45 deg with sufficient depth.

cheers guys i will keep you all posted on this front.

[tankbarrell]

You won't harden a rivet using the method you describe unless it is a high carbon rivet. Most rivets are mild steel and cannot be hardened to any great extent.

I have had success with the ball bearing method or using a ball end slot drill.

[Michael Hughes]

You will find it difficult to harden a rivet due to the stock they are made from.
If you keep the rivet head cold i.e. quenching as you go you should have no problems making the tools. The trick is to keep the tool steel red hot when forming it over the rivet.
Then there is a trick to hardening the tools as you need to quench at the correct temp for the tool steel you are using. You can easily make it too brittle.
If you contact a local Blacksmith Guild they should be able to help you in making the tools.

[RichardT10829]

thats great thanks Michael. I know Martyn had issues with the tool wearing out quickly but i dont believe he had re hardened it after heating. just saves me re forming the tool again. I will make enquirie cheers gang.

[Ron Pier]

I am interested in the comments made about the hardening of rivets. I'm no engineer!! When I restored my 2 pounder field gun I had to remove a few rivets from the shield. These were small dome head and countersunk. I could not drill them with even the highest quality drill bits. I could not grind the heads off as they are countersunk. The only way I could remove them was to cut the dome off and heat them with an acetylene torch till they were red hot and drive them out with a slim drift. Does this mean they were of a different steel that hardens when hot. Ron

[tankbarrell]

Ron, it's possible that AT gun shields used high carbon rivets as these would harden to a degree when formed.

We had no problem drilling out the Ram tank hull rivets.

[RichardT10829]

i have had similar issues with my carrier rivets specifiaclly the gunners side rear compartment armour. which is countersunk on both sides. i used a slitting disc to take the heads off then as you say Ron heated up the remains and punched them out.

[cantankrs]

Originally Posted by tankbarrell

We had no problem drilling out the Ram tank hull rivets.

Hi Adrian,

Were they 3/4" rivets? Presume you used a mag base drill. Did you remove the head from one side first? And did you use drills or annular cutters (Rotobroach)? Just wondering cos with my Grant hull out in the bush I used Oxy to slice off a head and we pushed some out with a pneumatic Rivet Buster when cooled when we had two people (and enough PSI). But then for the rest I needed to get out I cut the other head off too and used a packet of 3/16" drills and an air drill coupled to a modified drill press with some suds to drill the centres and then Oxy'd a "Y" so they'd collapse and then pushed the remains out with a hammer and punch while still hot. Tiny bit of damage to the plate or angle where I wasn't precise with the oxy. Interestingly 3/16" was the minimum drill size that would allow clear oxy penetration through the length of the rivet.

Regards

Alex