Square-headed coach screws - how do I solve a problem?

[Handyman]

OK, I know that square-headed coach bolts and coach screws have been around for yonks, and that hex headed ones are now widely available. But I've got a job coming up where I've got to insert the best part of 100 square-headed coach screws. Where can I get a socket or nut-driver head which will fit these?

Some of these screw heads will pull below the surface of the wood - even with a washer, once they are tightened, so a spanner is no good. When I ask local suppliers how to overcome this problem, they look at me as if I'm stupid. Am I the only person in the world whose coach-screw heads bite into the surface of the wood?

Help!

 

[david and julie]

I thought ordinary sockets fitted them. There are 12 segments inside the socket. Instead of the head sitting on every other segment it sits on every third one. I have undone them like this but to be honest I have had to tap the socket on .

 

[Handyman]

D&J, I know this is possible, but these things have been around probably longer than every other mechanical screw fixing. Surely someone has thought that a purpose-made socket for these things might be useful?

 

[david and julie]

Yes I know they've been around for donkey's, but to be fair nut runners and the like haven't.

As you know, the correct way of fitting these is to bore a hole first and then bore a larger hole, part way, to suit the washer, these washers were quite large to stop the wood splitting. This also lets you get a spanner on the nut. (in a fashion)

Square box keys used to be available but I've not seen one for years, perhaps they were superceded by sockets and thats why most have 12 segments and not 6?

Presuming you don't find what you are looking for, you may need bigger washers, such as penny washers(or thicker) to suit the larger socket size required.

I guess years ago time was not an issue, if our forefathers saw a nut runner or drill driver they would probably wonder what it is!

 

[david and julie]

Forgot to say, have you seen those converters/adapters that go in a drill driver to fit sockets? I got a set of 3 to suit 1/4,3/8 and 1/2 drive sockets.
They were about a fiver or so and are really useful.

 

[masona]

Can you not use a square plate washer ?

Overtighten screw into wood can split long term, is it because you want to hide the screw head ?

 

[Handyman]

is it because you want to hide the screw head ?

Well, sort of. It's because I want to fix some 6x2 on top of, and at right angles to, another piece of 6x2. I want to counterbore the upper piece and use 4" or 5" screws and Form A washers (I know what these are, now ) to bolt the two pieces together. This I can do with hex headed screws, but not with square headed.

 

[BR]

what about the likes of this?

 

[Antwerpman]

A normal socket will definately drive a square headed coach bolt, but if you dont like the idea of this why not switch to hex head coach bolts?? I cant see that there is any disadvantage to doing this and you can be sure your socket will fit

 

[david and julie]

About 3 years ago I did some decking and screwed some logs about 8" in diameter around the bottom for a decorative effect.

I used an American made, type of screw but unfortunately I can't remember the name.

They came in many lengths, mine were a foot long! were black hardened steel, the thread was only on the first couple of inches, like a very course woodscrew and was wider than the rest of the bolt. They were designed to replace coach bolts and needed no pre drilling or countersinking and did not split the wood even when close to the edge. They had a waxy coating(maybe ptfe)to help insertion. They also came with their own socket about 10mm x 3/8 drive and went in damp logs no problem with a good drill driver.

Sorry I can't remember the name but I got them from Arnold Lavers.

Perhaps someone will recognise my description and know the name. They were a bit pricey but very fast and easy in use.

 

[Handyman]

Ah, now BR seems to have found the answer.

I could change to hex headed, but all the suppliers around here only sell square headed, and say stupid things like "I've not seen hex headed before", or "I don't think you can get those around here".

Anyway, thanks BR. I sense a solution in the offing.

 

[Studders]

Ah, now BR seems to have found the answer.

I could change to hex headed, but all the suppliers around here only sell square headed, and say stupid things like "I've not seen hex headed before", or "I don't think you can get those around here".

Anyway, thanks BR. I sense a solution in the offing.

I just had the same sort of problem. I couldn't get access with a spanner to tighten them enough so I tried a socket. It worked after banging it on but I couldn't get the b*gg*r off again. So I unscrewed it and had a close look at square headed bolt and socket (the type with many angles - not a six sided one). It's the very corners of the bolts that stop the socket (11/16")slipping straight on so, I took a tiny bit off each corner with a bench grinder and hey presto a perfect fit. A bit tedious grinding all the bolts but you gain by being able to do them up with a socket and ratchet.

HTH

 

[blindmal]

hi all
im constructing a four poster bed for my wife for the most part this will be held together by square headed coach bolts with the heads proud of the wood for effect can anybody please tell me where i can buy these (squareheaded) about 60mm long and half inch diameter can i buy them in black also
anyones help would be much appreciated also could you suggest any cast iron or black metal embellishments i could use on the bed cheers.
malc.

 

[Hitachimad]

A Bi-hexagonal socket, or 12point socket fits square heads.


Something like this aswell...

http://www.screwfix.com/search.do;j...OSFFA?_dyncharset=UTF-8&fh_search=black+studs

 

[Sandy Beech]

If you are lucky the head of the bolt could well coincide with the drive end of a standard socket - 3/8, 1/2 or 3/4. If so you can make a female to female adapter out of a piece of hexagonal bar to drive the socket.