Strong headed screws

Sandtree

I dont know if there is something wrong with my technique but of late most the screws I've needed to put in mangle their heads / screwdriver slots exceptionally easily even when using a standard manual screwdriver. Is there something to look for when buying screws to not have them made of butter?

Removed a double socket yesterday with a view to either putting a spur off of it and/or a new plate with USB built in. Only just removed the screws before they were totally mangled. The backbox in question is tiny and has a fair amount of spare flex in there which wont push out. Trying to put the face plate back on and it takes a bit of force to push the plate back in place. Used new screws and they were slightly better but still slightly deformed and one of the screws wont go the last 5-7mm in.

nofoollikeold

The screws for electrical boxes are usually made of brass, which is soft.  
Check that the screw holes in the back box are clear.  They often get blocked with plaster.  If you have run, run a 3.5 mm tap through the screw holes, otherwise use a screw to clear the threads.  
By flex I assume you mean cable.  Back boxes shouldn't have any flexible wires in them.  

stuart45

I've found that the screws you get with anything made in China are useless, often the heads snap off when tightening up. When using an impact driver check the bit's not worn, or that can spin and damage the screw.

FreeBear

If you are mangling simple machine screws on socket face plates, you are doing something wrong. Either the screws have been cross threaded, or you're using metric screws with an old imperial back box. Either that, or using a screw that is way too long.

Use one of these to clean up the threads in the back boxes - https://www.screwfix.com/p/c-k-re-threading-tool-m3-5-x-0-6mm/59312

Sandtree

Just unscrewing the original ones mangled those ones. I didn't install the faceplates so no idea if they were put in wrong to start with. It could be that the backbox is imperial for the screws I attempted to replace with but the first went in with only modest pain just the second which won't. Are imperial metal backboxes still a thing or did they go out of fashion at any point?

nofoollikeold said:

By flex I assume you mean cable.  Back boxes shouldn't have any flexible wires in them.  

It has 2 runs of 2.5mm cable entering the top punch hole with about 2-3cm into the box. The outer insulation is then removed and there's several inches of the inner cable exposed (you can move the faceplate a good 5" away). The backbox is very shallow (dot and dab walls with backbox surface mounted on the structural blockwork) and so all the cable makes it a tight fit.

Not sure the absolute difference between flex and cable... though adding a spot light on 1.5mm cable the other day noticed the original cable is massively more flexible than what I bought for the new spot (though both are solid core and the same diameter) 

Le_Kirk

nofoollikeold said:

The screws for electrical boxes are usually made of brass, which is soft.  
Check that the screw holes in the back box are clear.  They often get blocked with plaster.  If you have run, run a 3.5 mm tap through the screw holes, otherwise use a screw to clear the threads.  
By flex I assume you mean cable.  Back boxes shouldn't have any flexible wires in them.  

I would agree with the comment but when/if you go to buy a tool such as above, don't go to an electrical wholesalers and ask for a tap, they will send you to the plumbing store next door.  Being an engineer I asked for a tap, only to get the stock answer and was told the proper word is a re-threader!

FreeBear

Sandtree said:Are imperial metal backboxes still a thing or did they go out of fashion at any point?

Imperial threaded back boxes went out when the UK adopted the metric system back in the 70s. They can still be found in older houses that haven't had a rewire to current standards.

coffeehound

Screwdriver wrong size or rounded off?  Giving them a quick buzz on a grinder can clean up the blade tip

Ganga

Also make sure you are using a good quality screwdriver as some cheap ones have blades that bend at the tip and can damage the screws .

Sandtree

FreeBear said:

Sandtree said:Are imperial metal backboxes still a thing or did they go out of fashion at any point?

Imperial threaded back boxes went out when the UK adopted the metric system back in the 70s. They can still be found in older houses that haven't had a rewire to current standards.

Property was built circa 2005 so we can rule that one out probably. A previous owner was a big DIY fan but their skill didn't necessarily match their interest... fortunately minimal storage so unlikely to have been carting around large amounts of old materials from the 70s.

On an unrelated problem... the hole cut for one light switch is notably bigger than either the backbox or switch on two sides. The chap had lightly screwed the switch in and used caulk (or some form of hard rubbery stuff) to fill the gaps. What'd be the better solution? Its an internal wall so there is a void behind the plasterboard thats been cut back too far.

Ganga

Le_Kirk said:

nofoollikeold said:

The screws for electrical boxes are usually made of brass, which is soft.  
Check that the screw holes in the back box are clear.  They often get blocked with plaster.  If you have run, run a 3.5 mm tap through the screw holes, otherwise use a screw to clear the threads.  
By flex I assume you mean cable.  Back boxes shouldn't have any flexible wires in them.  

I would agree with the comment but when/if you go to buy a tool such as above, don't go to an electrical wholesalers and ask for a tap, they will send you to the plumbing store next door.  Being an engineer I asked for a tap, only to get the stock answer and was told the proper word is a re-threader!

Never heard them called that ,i worked in engineering for over 50 years and they were always taps and dies .