self tapping screw or ali rivet?

[Relax]

I am also looking to install mast steps at some point in the next year or so and have looked at options - pressed stainless, cast alloy or nylon/glass composite - there does not appear to be much difference in cost between them?

I discarded the possibility of rivnuts because as stated above for a 5mm setscrew you require an 8mm hole - and that leaves little material between several of the holes - essentially you have created a much larger hole.

My personal take and what I hope to use FWIW is monel rivets 5 or 6mm as appropriate. I do have a concern in using these on composite steps in regard to the crush required to "pop" the rivet - this could potentially damage a composite step I would think?

 

[TiggerToo]

..he used rivet nuts, being of the opinion they were the safest option. I think he used M5 ss bolts, so the rivets need an 8mm hole IIRC...

what were the rivet inserts made of Alu or SS? the SS inserts are hard to deform and require a hefty instrument

 

[emandvee44]

Rivets

They were aluminium/alloy IIRC - I will try to find the article although I may have donated the mag. to the marina book exchange. Point taken about the hole size required, and it depends on the steps model viv a vis distance apart of the holes required.

In the interests of everyone, attached images of a rivet nut kit, and a typical alloy csk rivet.

Michael.