Coach screws for radiator bracket

[Jupiter01]

Can I use M8 coach screws with a “standard” radiator bracket? Wanted to check if the screw holes are likely to be wide enough.

Thanks in advance.

 

[muggles]

There's no such thing as a standard radiator bracket. Each manufacturer has their own design, and "universal" ones can be different again. Buy the radiator and measure the bracket if you really want to use coach screws.

 

[Madrab]

Worst case, you can always use an 8mm HSS drill to widen the holes.

 

[Jupiter01]

Thanks guys. You've got me out of a "hole" so may times! Really appreciate it.
Excuse the naivety of this question, I appreciate that a 8mm hole in the bracket will allow a M8 bolt to thread through it but what size drill bit and plug should I use in the wall please? Is there a definitive guide for these questions anywhere?

 

[denso13]

Can I use M8 coach screws

Why so large?

 

[Jupiter01]

I've packed out a wall with 50mm insulation and a layer of plasterboard. The plasterboard has a reasonably chunk of "dabbing" to get the wall plumb. I want to ensure that I get a reasonable amount of the screw into the wall. I will probably go for M8x170'ish

 

[muggles]

You'll need 10mm plugs for that

https://www.screwfix.com/p/fischer-high-performance-universal-plugs-ux10-10mm-50-pack/92197

 

[Jupiter01]

This states 6mm screw diameter. How would I know that this is what I require for M8 bolts? Just for future.

 

[denso13]

https://www.screwfix.com/p/fischer-sx-nylon-plugs-12mm-25-pack/71996

 

[Jupiter01]

https://www.screwfix.com/p/fischer-sx-nylon-plugs-12mm-25-pack/71996

Thanks. I can see that this states 8mm screw which I assume is the same as an M8 coach screw. Is it okay if the coach screw pierces the end of this? I'm aware that the drill hole will need to be deeper than the length of the plug

 

[denso13]

Is it okay if the coach screw pierces the end of this?

Yes, but don't over-tighten it or you'll pull the plasterboard inwards. M8 still seems a bit of overkill.

 

[Madrab]

Yeah, must agree, you shouldn't need anything larger than 6mm coach screw to secure the rads properly. If the brick/block is around 65mm in from the plasterboard then 120mm screws will be more than enough to hold a rad (size dependent) but you can get up to a 140mm length.

You can use a blue Rawlplug using a long 8mm bit, pop the plug on the end of the screw and hammer through till inserted into the brick then tighten.

 

[Jupiter01]

is there also value in inserting a second rawlplug flush with the plasterboard so that the screw is tight here too? Perhaps with the end of the rawlplug chopped off?

 

[denso13]

is there also value in inserting a second rawlplug flush with the plasterboard so that the screw is tight here too?

No, not at all, it will just push in or turn.

 

[bsr]

The Kudox rads I use always come with M6 coach screws and 8mm plugs and they seem more than strong enough.