Self drilling screws

[BAGW]

Hi,

What is the maximum thickness the self drilling screws can be used for? Is it possible to drill in a 1/2" thick member?

Tried looking at some manufacturer, could not find any screws that can be drilled into a 1/2" thick member.

 

[azcats]

According to this ESR the big teks screws can get 1/2".

[URL unfurl="true"]http://www.itwbuildex.com/pdf/ESR-1976.pdf[/url]

 

[NorthCivil]

If you have any consideration for ease of installation or workability, any field drilling and screwing into steel thicker than a millimeter or two at the absolute maximum should be avoided. If the drilling needs to be done in the field by a man with a handheld drill, the level of labour and physical exertion to drill these holes is incredible. even young fit guys can only drill for so long before they need a break, and can only drill for so long within a working day.

This is coming from an engineer who in a previous life spent a lot of time drilling into steel.

It also depends a lot on the hardness of the steel. Harder steels will not be able to be penetrated with self drilling screws at all. Hard steels will burn out well oiled drillbits too. I've had jobs with 3mm hard steel that needed drilling, and I was burning through 1 well oiled specialty drillbit for every 2 or 3 holes drilled.

 

[JedClampett]

Is there a reason to not predrill? You'll break a lot of screws self drilling them. A lot. It will probably cost less once you figure the cost of all the broken ones and the labor to put them in twice or more.

 

[Tomfh]

I use a lot of self drilling screws. 2mm is fine into mild steel. 3-4mm and it starts getting harder. Half an inch? That’s some impressive screws.

If you’re prepared to pre drill it becomes easier, but even then you can end up breaking screws due to too much friction. At a certain point the screw prefers to shear off rather than keep biting into the metal. Then you have to stuff around and remove the stuck screw, and figure a way to make it work.

 

[dik]

I've not experienced a lot of TEKS 3 or TEKS 5, breaking... they seem to be pretty robust.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[canwesteng]

For this kind of fastening, I'd usually go to HILTI powder actuated fasteners, much faster. What's the specific application? Can also use blind bolts

 

[BAGW]

canwesteng,

It is for attaching an angle to a tube. The force is very minimal in range of 1000 lbs.

Can HILTI KWIK-FLEX SELF DRILLING SCREWS be used to steel to steel connection?

How to combine shear loads (Vertical and horizontal) on screws? Is it same as bolts sqrt of sum of squares and compare with the capacity of bolts?

Thanks