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Machine Screw To Replace Rivet

Tall_Order

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Tight access area- had to drive 470AD4 rivets using an offset on fuselage internal rib structure. Long story short, it looks like I will have to go up a size of hole on the next try. Reluctant to go with #5 rivets as I think a similar result may happen again in this location.

Supposing I increase the hole size to 5/32", is it common practice to use a structural machine screw with appropriate grip length such as the MS27039? If so, what about using a "nylon lock nut" vs "metal stop nut" vs a "Hi-Lok Collar" on the machine screw.

Alternatively, if I use a Hi-Lok pin instead of a structural machine screw, how much undersize drill/tap should I use as it looks like there is a risk of the pin spinning in the hole if I drill the hole wrong.
 
AN509-8

I too had a AD4 rivet that had me use some inappropriate words after a couple tries...


I increased the hole size to #8 and installed a AN509 (MS24694) screw with a Nylock. I believe it's this one on the photo...

I'm not a structural engineer so this advice is worth what you paid for.


A metal lock nut would normally be used in high temperature environment like Firewall Forward.
 

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Somewhere I heard that different types of fasteners carry and transmit loads differently. I'd run it by Van's before substituting a screw or bolt where a rivet was supposed to go. If it were me, I'd be looking at a CherryMax rivet. Either an oversize -4 or a -5.
 
CherryMax

Somewhere I heard that different types of fasteners carry and transmit loads differently. I'd run it by Van's before substituting a screw or bolt where a rivet was supposed to go. If it were me, I'd be looking at a CherryMax rivet. Either an oversize -4 or a -5.

Agree. Ask Vans first. CherryMax has intermediate sizes so you may not have to go to #5.
 
Appreciated

Thanks all, for sharing some ideas to consider. Due to tight access and the need to pull straight, would have to pick up a swivel riveting tool if I opt for cherrymax in this location.

Aside from this particular spot, I do have a general interest in learning more about the various threaded/alternative structural fasteners available. This interest grows after "strike 1" on a difficult location rivet install... :)
 
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