Self tapping screws for stainless steel

[reb78]

I need to fasten some composite decking to stainless steel steps. Is there a particular type of self tapper I should look for? Needs to have a nice looking head that will sink flush into the composite. Some sort of hex or allen head might be nice and save me rounding them off. The stainless is prob 1-1.5mm thick.

 

[frank horton]

pilot drill then drive a norm screw in first....take it out then put ur st/steel screw in.....well worth the effort...
as an add on, I only use Hss with cobalt dril's for st/st....
the st/steel screws are really soft.....
I use them a lot in wood.....unless I do the above the screws will often snap esp when taking them out....

and for norm st/st nuts and bolts go slow with the nut gun as threads gaulup quite easy....

 

[500e]

50 Brindle difference in nut /bolt hardness will help to stop galling.
We used a lot of SS fasteners re building Morgan cars, cheap stainless can gall even with hand tool.
@Hood could be the man to advise

 

[8ob]

I would be wary of altering the rising unless all steps inc the floor/landing were exactly the same,6mm difference is enough to cause a trip hazard.

Bob

 

[reb78]

I would be wary of altering the rising unless all steps inc the floor/landing were exactly the same,6mm difference is enough to cause a trip hazard.

Bob

All taken into account Bob. This is to secure the riser. We used CT1 adhesive but its already coming unstuck in places so needs a screw. The tread is already secured with screws into batons but I cant use a baton behind the riser.