Tek screws

[suffolksmallholder]

You should be fine with the correct Tek screws as others have posted.
If not try one of these:

VersaDrive® Impacta DrillTaps - Metric Coarse (301125)

VersaDrive®ÃŠ Heavy Duty Impacta-Drill Taps are an industrial metalwork or fabrication tool for drilling and tapping heavy steel in one easy operation. Order today!

holemaker-technology.com

I will acquire one of these at my earliest possible convenience. Job done!
SS

 

[Kidds]

I have used these to fasten to the girders in my shed.

Easydrive Flange Self-Drilling Screws 5.5mm x 38mm 100 Pack - Screwfix

Order online at Screwfix.com. BZP. For fixing corrugated sheet metal to steel constructions. Excellent quality for general exterior construction. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[Zippy768]

Looking for some advice.
Our house uses heavy RSJs as lintels across large bi folding doors.
I need to attach a screen to the underside of the lintel as I dare not put too much weight into the bi fold structure
I am having issues fixing to this , have got some tek screws but they keep shearing. So far I have got 3 holes and 3 sheared screws and a distinctly underimpressed wife☹
The weight is not great , about 4 kg but worry that grandson may choose to swing on it and do sone damage to the door frame.
Can anyone explain to a simplton like me about the correct tek screws for putting into the RSJ

Just to be curious and nosy , what exactly are you trying to do? What do you mean by "screen"?

 

[sodbuster2]

TechFast Sheet to Steel Heavy Duty Self Drilling Hex Roof Screw

www.toolstation.com

These are for fixing to beams etc and unlikely to shear

 

[Exfarmer]

Just to be curious and nosy , what exactly are you trying to do? What do you mean by "screen"?

Its justa chain fly screen. We already have one elsewhere , which is just literally screwed to the top of the frame but this new screen. Is very much heavier and stronger. It is to go over the opening section of a 5 section bi fold door and I am not at all sure if there is any load carrying capacity when the door is fully open.
I would be a little unhappy if grandson decides to do a tarzan swing and break the wooden frame. It does not look very strong. Hence my desire to screw into the RSJ above.
Think I may investigate the idea of tapping further

 

[simmy_bull]

TechFast Sheet to Steel Heavy Duty Self Drilling Hex Roof Screw

www.toolstation.com

These are for fixing to beams etc and unlikely to shear

These are the ones I’d try.

 

[bobk]

TechFast Sheet to Steel Heavy Duty Self Drilling Hex Roof Screw

www.toolstation.com

These are for fixing to beams etc and unlikely to shear

I used them , they're w4nk .

 

[michael N123]

The problem with Tek screws is you end up fixing everything you shouldn’t with them as it’s fast

 

[Tinman Steels Ltd]

The reason for them shearing is because they are trying to cut and screw at the same time.

General rule is:

Stitcher fix - 6.3mm x 22mm stitcher is designed to cut and screw 2 x 0.7mm sheets of steel.

Light steel fix - 5.5mm x 25mm, 32mm ect...light steel fix is designed to cut and screw into 1.5mm - 3.5mm steel. Most of the drill tips are around 4mm - 5mm and then the thread hence why these would be shearing.

Heavy steel fix - 5.5mm x 38mm, 60mm ect.... heavy steel fixing is designed to cut and screw into 5mm - 12.5mm steel. Most of the drill tips are around 14mm - 15mm and then the thread. This allows the fixings to cut upto the 12.5mm steel and then start to screw once it gets to the thread.

You will always find some fixings are better than others, I've always found i-fix or drillitt are good brands for heavy steel.