Self drilling screws query

[ecurran]

Hi folks

With regards to attaching boxes to steel gate posts etc I normally tap & screw however this can be tedious when doing many fixings. Lately I've been reading up on self drilling screws & my question is which type would suit my needs?

I install electronic security & my up & coming install is to attached Intercom entry panels to steel gate posts & I have seen the below screws which seem to suit the job;

http://www.screwfix.com/p/rawlplug-...el-screws-washer-5-5-x-32-x-3-2mm-pk100/92744

I have read that certain screws can drill up to 1-2mm & others 5mm steel, most steel posts that I encounter are mainly up to 3-4mm, would the above cover from 1-12m steel thickness?

Thank you
ecurran

 

[Norcon]

That will penetrate about 3mm mild steel.
4mm and its gets more difficult.

Drill a pilot hole for thicker steels.

 

[RF Lighting]

I use these all the time for fixing light fittings, conduit, switches etc to steel girders. You'll wonder how you ever managed without them.

Best to install them with an impact driver I've found, and you need you use proper Philips screwdriver bits, not pozi ones.


http://www.screwfix.com/p/timco-cla...-pan-head-screws-4-2-x-25-x-4-2mm-pk200/71172

 

[ecurran]

Thank you both for your replies.

RF Lighting, the ones you recommend do they screw straight into steel without the need for a pilot hole? I don't have an impact driver so I guess that will make the job more difficult without one?

 

[RF Lighting]

Yes no pilot hole required unless the steel is really thick but they seem ok upto about 6mm without.

You'll be ok with a normal drill driver on top speed it'll just take a bit longer to get them started.