Self-drilling screw into 3/8" steel?
#1
Self-drilling screw into 3/8" steel?
The "self-drilling" (2 1/2" long with 3/16" shank) screw pictured below is the type that was used (among several others like it) to secure the top plate of a wood-framed wall to the bottom flange of a steel I-beam of 3/8" thickness. My inquiry here is whether once these screws have been used, as just described, if they could be expected to be re-used and the tip would still be sharp enough to drill through into the steel again or are the tips pretty much spent after one such use and I'd need to use new ones. Also would I necessarily need a power drill stronger than mine which happens to be an 18-Volt, 380-Watt motor cordless?
#2
That type screw will still require a pilot hole, as it is self tapping, but not self starting. I would not re use the screws, as the shank has been compromised due to torque on the original install. They can't be that expensive. It is also better to use an impact driver for such installation.
#3
Another reason not to reuse the screw is that you can see the starting threads are worn flat.
#4
I have had some success using self-tappers into 1/4" steel posts but not 3/8". Here is the method I have used:
Use a drill bit the same size of the self-tapping end of the screw to drill a pilot hole through the 3/8 steel. Then run the screw through the wood and into the steel.
Another option is to shoot nails through the wood into the steel using a powder actuated nail gun. That is how I see commercial carpenters attach steel studs and track to steel building structure. Although they are using very short pins as the steel studs are only 24 ga. Just make sure to wear hearing protection!
Is this at home or at your work? If it is at work, I am wondering why you are not using steel framing?
Use a drill bit the same size of the self-tapping end of the screw to drill a pilot hole through the 3/8 steel. Then run the screw through the wood and into the steel.
Another option is to shoot nails through the wood into the steel using a powder actuated nail gun. That is how I see commercial carpenters attach steel studs and track to steel building structure. Although they are using very short pins as the steel studs are only 24 ga. Just make sure to wear hearing protection!
Is this at home or at your work? If it is at work, I am wondering why you are not using steel framing?
#5
That type screw will still require a pilot hole, as it is self tapping, but not self starting.
It is also better to use an impact driver for such installation.
thanks
#6
Another reason not to reuse the screw is that you can see the starting threads are worn flat.
Not that I will be attempting now on trying to re-use the screw(s) (per chandler's advice), but just sayin'....
#7
Use a drill bit the same size of the self-tapping end of the screw to drill a pilot hole through the 3/8 steel.
Is this at home or at your work? If it is at work, I am wondering why you are not using steel framing?
#8
Member
I would use screws that have a standard SAE thread and diameter, I would purchase a thread tap (for SAE screw), a tap drill for the steel and a clearance drill for the plywood. Drilling 8 holes in steel and plywood with a battery powered drill should not be a problem. Have the plywood in place when drilling the holes in the plywood so the clearance drill marks the tap hole location in the steel. Use engine oil on the drill and tap when drilling and tapping the steel. Good luck
#9
"Cobalt" is just a come on name, to make you think it is made of Kryptonite or something. Likewise with "Titanium". You can drill 3/16" pilots, but buy a few bits just to be on the safe side. Metal is tough on today's bits.
Your drill will bottom out or stop spinning when a certain torque is reached. An impact driver does not stop spinning, adds impact and added torque per hit to assist in putting the screws in place.
Your drill will bottom out or stop spinning when a certain torque is reached. An impact driver does not stop spinning, adds impact and added torque per hit to assist in putting the screws in place.
#12
The reason I asked, around here carpenters are mostly required to use steel framing or wood framing that has been fire treated in commercial spaces.