Rivets

Needing to use rivets (Iron & copper in various sizes) for the first time in years - is there anywhere a chart of how much to leave protruding so it hammers neatly into a countersink with a small amount to be removed by filing?

Too much is extra work to remove and too little needs filling or replacing depending on the shortfall.

Thanks,

Nick

If you click on the type of rivit you have they give the setting allowance, it can vary a bit but use the chart as a starting

Thanks Jason - Just what I needed.

(If I had been aware of the term 'setting allowance' I might have found it myself!)

Nick

If the application is critical, then I recommend testing first with a replica setup.

Don't sweat the numbers, it's only a starting point. The actual allowance is heavily dependent upon the rivet snap and the fit of the rivet in the hole. Before I riveted the wheels on my traction engines I formed a lot of practice rivets, varying the allowance to see what worked:

This was particularly useful as I was using home made snaps. For consistent heads it's best to aim for better than ±5thou on length. Since I had to shorten hundreds of rivets I made a top hat split sleeve and shortened the shanks in the repetition lathe which gave excellent consistency. It's better to be slightly under rather than over on length.

All rivets are 3/16" steel.

Andrew

Edit: Ooopsie, just noticed the OP was asking about countersunk holes. The theoretical answer is pretty simple maths, cylinders and truncated cones. But it's best to experiment. More is better than too little. There needs to be enough metal moved to the outer edge to completely seal the edge of the countersink. One won't get the formed rivet head perfectly flat, so best to get used to filing! Leaving the formed head proud will also ensure that filing removes all hammer marks.

Edited By Andrew Johnston on 05/01/2021 09:55:24

For larger sizes old car push rods cut down to a suitable length work well. Noel