HSS jobber drills will work nicely, preferably nice sharp 'new' ones......I get through loads and Screwfix' Titan ones are just fine but there are many others. Start with a small diameter and work up to the size required. A good drench of WD40 will help too, and bring the drill out from time to time if the hole is deep to clear the swarf.
John
Thanks John that's really good advice and I really appreciate it. Previous owners fitted a wooden lintel over a set of 3 meter bi-fold doors and I'm having the beam replaced as it's just not safe at all. How on earth people get away with it I don't know. Once the new RSJ is in position would you find a few good fixing from the top of the frame and screw it to the plate that's on the new RSJ?
Thanks John that's really good advice and I really appreciate it. Previous owners fitted a wooden lintel over a set of 3 meter bi-fold doors and I'm having the beam replaced as it's just not safe at all. How on earth people get away with it I don't know. Once the new RSJ is in position would you find a few good fixing from the top of the frame and screw it to the plate that's on the new RSJ?
Got you, that makes sense. Structural engineer has specified a 203x102UB23 with a 250x6 Plate intermittent 6FW to UB (75 weld 100 gap) sat on pad stones/blues.
Doesn't mean much to me though other than paying for the calcs and the cost of the beam and labour to fit it
With this in place, drilling and screwing the tops of the bi-folds in should be ok shouldn't it?
What sort of fixing would you use to do this?
So it's been pre-drilled along the "web" and the "flange" but the plate along the bottom cannot be drilled until it lines up with the bi-folds so therefore need drilling once it's in situ. I could be wrong but that's what I went for.
12mm x 8mm took about 5 minutes using my sorry collection of rubbish drill bits:
Start with a 1mm and work up a few mm at a time (it takes me longer because I have to keep trying till I find a sharp one). I find a bit of spit or even cooking oil will lubricate it enough. Eye protection essential and be wary of the small bits snapping in the hole - they often won't come out and you'll need to drill elsewhere.
In terms of fixing, unless you have a tap and die set you'll need self tapping screws - there are roofing screws designed for thick steel but think about the (bolt type) heads being on view in your frame. Can you fix timber above the steel to screw into?
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