Self taping screws for steel

[marsaday]

I have some strap over joist hangers which will go over my steel. I need to drill the steel and screw some screws in to hold the joist hanger from the top.

Any idea what size screw to use and what sort of screw. do i just ask for "self taping". Will 6mm thickness be ok.

 

[^woody^]

Will they "self tap" into such a thick steel section?

Can't you Hilti nail a section of 4x1 or 4x2 to the top of the beam and then just nail the hangers as normal. Then you don't need lots of holes in the beam

 

[mointainwalker]

woody is right.

Self-tappers are designed to hold in sheet-steel . They will not cut a thread in an RSJ.

 

[marsaday]

ok, so self taping is out. I can use normal screws to go through into the joist then.

Cant add a timber plate as this will reduce the height of the room.

 

[^woody^]

If you have inserted a timber within the web of the steel, then you could use some of the various face fix hangers and nail these into the timber

 

[marsaday]

This is what i am using - speedy ones. but they bend over to fix into the top as well.

So they are face fixed, but i thought i needed to fix from the top as well.

 

[^woody^]

No, speedy hangers are different

Face fix are normally thicker steel, and only as deep as the joist, and do not bend like the thin speedy hangers