Phil,

Rotagrip sell spare square headed set screws for the Dixon tool holders.

Barry

I'm pretty sure I got some from a UK supplier of spares for multifix but they were not cheap.

However create tools in China do the cloned multifix tool posts. There is a thread on here with contact details for Nina Wang who was very helpful in supplying tools. There was no problem buying from China so drop them a line.

Regards Mick

One US supplier here

Typical far eastern supplier but probably need to buy qty

I'd just get the spin indexer out.

Have a look at

http://www.nssocketscrews.com/index.php/html/standard/square-head-set-screws

This gives relevant DIN standards, which are useful as search terms.

Long time ago, I bought M8 ones from Nu-Screw in Neasdon, about £40 per hundred, but I cannot find their website any longer.

What is wrong with dog point hex. grubscrews in your application? I like them better than traditional sqaure head as they are cheap, you can pick a length to suit the tool being clamped so they do not poke up so much that swarf wraps around them.

Never found socket heads filling up with swarf to be an issue for me, apart from two holders that I use for one off tooling the rest just stays in the holder and the screws never get touched which is the idea of a QCTP apart from the boring bar ones that may get adjusted for length but that's at the start of the job before the swarf gets produced, just tip upside down when you take them off and swarf will come out the screw heads..

Tee shaped key hex or sq socket means you can spin the screws in and out easier than with a spanner on a square headed screw

Holders

But if you read on

"I am now making an additional four toolholders each having three screws"

Also early on Multifix holders were mentioned by the OP, they use square heads on the holder both the set screws for gripping the tool and also the height adjuster, none on the actual toolpost.

Finally you also mentioned them needing machining at "the holding end"

Edited By JasonB on 27/06/2019 14:46:19

I bought my Colchester several years ago at a government auction and my lathe came from a batch of machines from a prison, the Dickson wrenches and the saddle lock spanner were heavily etched with a number ID and all the square headed screws were missing from the Dickson tool holders ,no doubt they were held in secure storage as they may have been useful to the inmates,it cost a fortune to get replacement screws as they were whit or unc . One tip with Dickson tool holders all of mine have 3/8 square heads so I have adapted the 3/8 drive extensions from socket spanner sets , the socket fits over the square screw head and at the other end I have drilled a cross hole to take a silver steel tommy bar to make a T wrench ,a lot quicker to use than the dickson wrench. This T wrench also fits the locking screws for the top slide of my Myford Super 7 and makes access to the right hand screw a lot easier.

Why bother with sq hd screws if they cost so much ? Hex Hd will work just as well.

The (normally four) holes in the holder are so close together that the points of standard hex. screws would clash.