Hope you can help

I fitted a hammock in the campervan this weekend

the screws that came in the fixing kit were only fit for the bin cheap nasty self tapping screws. I used a rivet to secure the bracket (no. 4 size), is this going to be strong enough ? My friend who is an engineer reckons not due to movement on the rivet etc.

Last thing I want is it collapsing whilst my son is asleep on it !

Many thanks

its a hard one to call.

personally i would be going with a self tapper

also i would be using epoxy resin behind it then screwing it tight.

There isn’t a right answer as a well fitted screw is better than a poorly fitted rivet and vice-versa. Personally I’d use screws but more for the ability to take it off or move it at a later date. Either should be fine if done well.

many thanks so far

The right answer would be rivnuts, as used on bottle cage mounts on bike frames.
A self tapper is stronger than a rivet, for a given diameter of fastener, because it is solid steel, not hollow aluminium.
However, car body panels are pretty thin, which doesn’t give a self tapper much to bite in to, so I’d guess that screws pulling out is more of a risk than rivets shearing, so I’d go for rivets.

As above, rivnuts are the solution, but failing that I’d choose a coarse thread self-tapper for this application over a rivet.

What you need is a “nutsert” or “threaded insert”:

Although they need a tool to set them, you can do it with an old bolt + nut + couple of washers.

These will correctly spread the loads into the thin panel, and not come loose over time.

That’s a rivnut…

FWIW, I’d go with a rivnut (or rivet) rather than a selftapper in a car – panels are thin so a self tapper isn’t going to have much contact (1 thread really, most likely). If I could get a nut in behind it then maybe I’d go with that (with some decent sized washers too) but I expect that’s not an option.

Depends on the metal used in the rivet

But Maxtorque has a good answer

Maxtorque, that’s what I meant by rivnut, same thing, different name.

Another option would be bigger rivets.
Most pop rivets are 1/8″ or 3/16″ (3.2mm or 4.8mm). We use bigger 1/4″ ones at work which need an air tool to set them and are much better suited for structural applications.
If you’re anywhere near Kidderminster and want to drill all the holes ready, I could put a few in for you.

If you are sticking the bracket to the door pillar I would be tempted to sand down to bare metal and use the strongest epoxy you can get, with rivets.

Rivnuts are good in applictions where you might want to remove and re-use the fixing via the screw. If its a one-time fixing then there is no real benefit over the right blind rivet. I’d prefer the rivet over the self-tapping screw in any applicaiton. I hate self tapping screws into sheet metal with a passion.

The main issue with clinchnuts… Is the hole size required which may limit the space ( you’ll need at least two to stop it spinning). Also the kit required for a one off job may be a bit much!