Self tappers into lintels

[Keitai]

Seem to be able to get self tappers into my Van's roof but I've struggled when going into a lintel. I believed it was metal I was going in to. SDS wouldn't go any further. I've snapped the bit etc.

Is it 3mm metal bit then the self drilling or normal self tappers ? Is it just patience, good metal bits and engineering oil?

 

[foxhole]

You need techfast screws,

Your van roofs about 1-2mm thick while a steel could be around 10mm , so no comparison.

 

[Burnerman]

A catnic type lintel is no problem, but H section not really....what thickness of steel are you talking about?
John

 

[Wayners]

I've done it with dewalt drill bit.
Go on a slow speed so drill bites and was easy to do. Took about 30 seconds to go through in a kitchen. I was fitting a blind.
I turned speed down on drill trigger

 

[Keitai]

A catnic type lintel is no problem, but H section not really....what thickness of steel are you talking about?
John

One attempt I failed was in this far corner of reveal

 

[foxhole]

The techfast screws will go straight into a 10mm H section steel with ease, fitted my patio doors with them (100mm screw)

 

[Keitai]

The techfast screws will go straight into a 10mm H section steel with ease, fitted my patio doors with them (100mm screw)

Is the above window reveal 10mm H section steel? Would you pilot hole first with a good 3mm drill bit despite being self drilling?

 

[foxhole]

Is the above window reveal 10mm H section steel? Would you pilot hole first with a good 3mm drill bit despite being self drilling?

No need, the screw provides the correct size hole.

 

[Deleted member 174758]

I've used several hundreds of the Hilti "self drilling" screws over the past 7 or 8 years, mostly into 5 to 10mm thick tubular UBs and RSJs - thicker steels invariably have to be pilot drilled unless you want an unacceptable number of burn-outs or breakages (even with an an impact driver which has a torque sensing TEK setting, and this is same advice that the Hilti reps give, too)

When drilling any metal it always helps if you "spot" the drilling point using a centre punch and hammer first - reduces the tendency of the drill to skate off. reduces the chanmces of injury and bit breakage, and starts the cutting process more easily. Also, if not already mentioned, metal drilling should be done at lower speed than wood (so 500 to 900 rpm)

 

[Keitai]

I've used several hundreds of the Hilti "self drilling" screws over the past 7 or 8 years, mostly into 5 to 10mm thick tubular UBs and RSJs - thicker steels invariably have to be pilot drilled unless you want an unacceptable number of burn-outs or breakages (even with an an impact driver which has a torque sensing TEK setting, and this is same advice that the Hilti reps give, too)

When drilling any metal it always helps if you "spot" the drilling point using a centre punch and hammer first - reduces the tendency of the drill to skate off. reduces the chanmces of injury and bit breakage, and starts the cutting process more easily. Also, if not already mentioned, metal drilling should be done at lower speed than wood (so 500 to 900 rpm)

View attachment 268013

Is it worth getting a set or just single one

 

[Burnerman]

My spring loaded punch lasted about 10 pops......solid ones every time now.
You need a good punch mark to get the drill to start.
John

 

[blup]

If you are fixing blinds or the like, self tapping should be fine. Drill pilot hole slightly smaller e.g. 3.2mm for a 3.5mm screw (Makita and Dewalt do them), and that helps get a tight fit whilst not making it impossible to drive the fixing in. Start with a smaller hss bit to help build up the hole diameter . It takes time but so long as you avoid overheating the bit, works well. Drive the screw home slowly.

Blup

 

[Deleted member 174758]

Is it worth getting a set or just single one

The spring loaded one which says "centre punch" isn't - it's a spring loaded marking punch which is used to set a point which you enlarge using a centre punch. You normally only need one or maybe two centre punches - the size depends on the drill sizes you imtend to use. Mine came in a general set with some taper and parallel punches

 

[Burnerman]

Mine still only lasted 10 pops
John

 

[Deleted member 174758]

I got marked down for mis-describing an automatic marking punch as a centre punch in a test paper when I was doing metalwork at school many decades ago - it still sticks in my mind. Centre punches aren't strong enough to mark a starter point for drilling in many cases - something must get lost in translation from English to Chinese an back again, or maybe they don't give two hoots

Mine still only lasted 10 pops

Should have bought a Moore & Wright one, then!