Chassis rivet size?

[Howard Wright]

Hi All

I'm going to be riveting the various parts of the chassis together in the not too distant future.  I can't seem to find anywhere that will tell me what size rivets to use.

I guess most rivets are 1/4" although the brake cross shaft holes seem smaller.  How long do the rivets need to be before being hot hammered down.

Thanks in advance

Howard

[Greig Smith]

Howard I've done this exercise several times, the tail or protrusion of the rivet needs to be as long as the other side flattened head is wide.
Over the years Dad has gathered a large selection of 'stuff' so we've never actually bought rivets, just sorted out the ones we want from the box. You will need 2 people or three if you have some mates that owe you a favour...

Once you have the rivet cut to length and in place you need to place the existing head onto a suitable anvil - in our case a few hefty bits of heavy steel with suitable size holes countersunk into them to locate the head neatly. You will need two of these, one in the vice below and one to whack on from the top.

Clamp the bottom one securely in a heavy vice then fit the rivet into the hole, pick up the chassis & locate the rivet onto the countersunk hole in your new special anvil. Using an acetylene torch quickly heat the stub end of the rivet red hot and then using your top anvil and heavy hammer clout the red hot end hard. A few practice tries and you will soon get the hang of hot riveting. You will need to cool the hand held anvil off periodically.

Aye
Greig

[Chris KC]

Hi Howard,

The clearance of the rivet in the hole is important in a structural joint. The hole diameter should be 17/16 x the rivet diameter (i.e. d + 1/16d)

You should be able to work that backwards to the correct rivet size if you know the hole size.

The length of the rivet protruding from the surface before forming should be 1.5 x the hole diameter (1.5D).

Greig's method sounds about right but you may form a better head shape if you invest in a pair of snaps & sets.

[Howard Wright]

Excellent Greig

Thanks that is just what I needed.  I hope to make up a static snap for below and an SDS fitment for my hammer drill, as Parazine demonstrated in his excellent thread. 

Yep I'll be organising a rivet party in due course.

Cheers

Howard

PS putting box section inside the rails is a good solution but I aim to run as "standard" in VSCC trials and that might just raise too many eyebrows!!

[Ian Williams]

You can grind a drill bit so that it is ball nosed and produce a hollow in your anvil with that, Chris is bang on with his suggestion of a 1.5 x diameter protrusion

[Parazine]

Rivet diameters seemed to vary when we hot rivetted our chassis. Some were 1/4", most were 5/16" and the diameters varied for the same location on a '26 and '29 chassis! The brake cross-shaft ones were 3/16" on both. All available on eBay. We did spend a lot of time getting them cut to the right length, which was critical.

I made up the most of the snaps we used although some of these broke due to faulty heat treatment! A reground twist drill made an excellent form tool to make the semi-spherical indent in the snap. I used silver steel as the base material.

[Bob Kneale]

I made up the most of the snaps we used although some of these broke due to faulty heat treatment! A reground twist drill made an excellent form tool to make the semi-spherical indent in the snap. I used silver steel as the base material.

Another way to make the hemispherical indent in the snap is to hammer a suitable sized ball bearing into the snap (we've all got lots of scrap ballraces around).
Heat treat the finished snap and it will serve you well!

Good luck.

[Chris KC]

Oh yes, and if you are going to use a 2lb hammer and the girlfriend is holding the snap for you be sure to aim well.

As they say, 'don't ask me how I know this'...

[Howard Wright]

Thanks Everyone

I now have a pretty good idea....

Hammer the wife with riveting A7 trivia 'til she snaps!!!

Cheers

Howard