Proper Rivet Height

Hello all

I have noticed a difference when I use flush vs non flush rivets as far as the rivet measuring tool.

On flush rivets the shank of the rivet when Vans calls for a 3-3 for instance is the correct height if I am measuring from the flat part of the skin. If I measure from the top of the dimple it is consistently short.

Going up one half size makes it correct and when driven seems to have better dimensions.

Everything I have seen always shows non flush rivets in the examples on correct formed head dimensions. Is there something I am missing on flush rivets that they can be shorter?

Are you sure your dimples are properly nesting? No space between top and bottom pieces?
And yes, sometimes, if the correct rivet length is between sizes, Vans will specify one that's a bit short - especially if the load is in shear. This is a builder judgement call - if 1/2 length extra looks better, and can be driven without bending it over, then used it and move on.

BobTurner said:

Are you sure your dimples are properly nesting? No space between top and bottom pieces?
And yes, sometimes, if the correct rivet length is between sizes, Vans will specify one that's a bit short - especially if the load is in shear. This is a builder judgement call - if 1/2 length extra looks better, and can be driven without bending it over, then used it and move on.

Click to expand...

Aloha Bob

Yes the dimples nest well together. Using Substructure dimples inside and normal on the skin.

Sent a question to Vans also, will post the reply here.

From Sterling at Van's

When a shorter than optimal rivet will still produce a satisfactory rivet head we will typically error on the short side, section 5 describes this in more detail. Ultimately you should measure from the face of the dimple and not the flat sheet. In some cases you may find a buildup of tolerances that may result in a rivet being short and not meeting mil-spec but this is rare.

Dimpled skins require longer rivets



Dimpled material next to shop head requires longer rivets than countersunk.

Finn

Thanks FinnFlyer

That's what I have been seeing. Just wanted to make sure I was using the gauge as intended.