hi,im building a small extension,se has specd tec screwing wall ties to a 5mm thick vertical steel post,i dont have a tec driver,so could i predrill the steel and screw in with a socket,or use a normal cordless with a nut driver,any ideas/experiences,thanks
Cordless driver with a socket bit. Although I would use a corded drill as it more than likely will knock the guts out of your batteries.
Tec screw's do the job of both drilling and screwing at the same time making it more efficient time wise.
so i dont need a fancy driver,just a corded/cordless drill with a socket driver,thanks all
The latter - probably depends on the screws a bit (makes and models) but a regular drill driver and either a hex driver or an adaptor and a socket should be fine. Generally the fast you get the screw spinning the better - impact drivers work really well. You'll probably find the screw makes quicker progress drilling the steel than you would with a drill bit.
The screws come in different lengths, the thing to make sure of is that there is plenty of the drill part of the screw to get clear through the 5mm before the threaded part starts to bite, but not so much screw that you hit the other side of the post
Make sure you use something with a ratchet (drill driver) rather than a corded standard drill without a ratchet. Once the drill tip goes through the steel and the threads catch, they wind in pretty quick and if you don't stop in time, and without a ratchet, you'll snap a head off.
Oh, and with 5mm steel, make sure you go for fine thread Tek, otherwise you'll again going to snap the head off with a coarse thread.
Pre drill with 4,2 mm cobalt bits! Then use a decent cordless which'll piss thro the remaining steel. We fix all the brackets in this manner at work prior to starting on the brickwork superstructure.