Self Drilling/Tapping Screws Dilemma

[Ken Massingale]

We just had a metal shelter built for the Kubota and stuff. The frame is 12 guage galvanized steel. The erectors, Carolina Carports (great folks and products), used self drilling screws to assemble the frame, roof etc. They left several dozen for me, and I used several to install some shelf brackets. No problem, I used the Bosch PS40 impact driver and a Ridgid cordless driver and with minimal pressure the screws went in easily.

Yesterday I started to install 1/4" pegboard on 2 interior metal studs. It took much pressure to get the screws to drill, I mean a lot. After the screws bottomed out, the holes are bigger than the screws, the darn screws can be pulled out by hand. Same thing with the impact driver or drill. I did several, making sure I held the driver/drill steady and straight.

Any ideas? This has me puzzled. :dontknow::help:

Thanks, please tell me where I am causing this.

Ken

 

[ehpoole]

Do the screws still have full and complete threads? Harder steel can strip the threads, especially if the screws were overdriven (such as with an impact driver). Sometimes it is better to predrill the hole and drive the screw either by hand or with a more torque limited tool such as a drill equipped with a torque limiting clutch.

HTH

 

[steviegwood]

I have the same type of building and if the screws happen to have been used before this can happen. also I had some screws that the drill part was bigger than the thread part. Steve

 

[Joe Scharle]

Ken, this may help.

http://www.mcfeelys.com/icatalog/spring/f/40

 

[Gofor]

Having used these before, I found two things help:

1. Slow down the drill speed. Too fast will melt the self-tapping tip.

2. For peg board, try drilling through it first, and then use the self-tap. Peg-board and sometimes a knot in plywood will gum up on the tip, again causing friction and ruining the self-tap feature.

They sell them at Lowe's if you need more.

Go

 

[CaptnA]

How thick is the metal interior stud and how coarse the thread? Is there enough metal once drilled for the thread to catch in?
I've used self tapping metal screws and had problems in very thin metal. Just a thought