Seeing what you put at the end of your other post use the shaper to cut each corner in turn.

J

I've quickly made various square spanners with a hacksaw to cut vees and arc welding the halves together Colin

to make a round hole square: the proper way.

Start with a nice hot coke fire. Take a piece of square carbon steel bar of the finished hole size, heat one end to bright red. WIth a 2 pound hammer, gently taper the end over your anvil so it will enter the round hole. Anneal and temper to straw, but for single use, just let it cool slowly.

Heat the spanner blank, drive the drift into the hole until sized correctly (multiple heats may be required for larger work). Dress off, cool, and you're done. Easy!.

(of course, the proper way to make the round hole in the first place is to punch it!).

-russ (sometime blacksmith..)

There is a technique using a triangular ended drill with a square guide bush (thin, made by filing).. Probably searching the ME index will find an article. The 'drill' is held in a flexible drive. Side of triangle = side of square.

I think there are some commercial versions of the above and I think films on Youtube.

The 'proper way to do it was with an Armag profiling head.

A square broach is another way. As well as the carefully made multistep broaches some blind hex and square holes are made just by wholloping a hardened tool into the hole. This method leaves teltale curles of the cut metal in the bottom of the hole. I expect the end of this tool is recessed and ground off when dead hard to leave a sharp edge.

On your Excell have you worked out what the hole half way along the over-arm is for?

As with Chris;

File a round hole square …basic apprentice hand tool excercise; same as making a 1" cube out of 2" round bar.. to tolerance, using only a hacksaw, set of files, Engineers square & feeler gauges, part of my first 6 mo. as apprentice, then onto scraping bedways / bearings (min 25points per sq inch or else you got your ears slapped..not pc now). no mechanical assistance back then, followed by using a lathe/mill/drill,.blah, blah! , all long gone expertise, for some!… its all CNC now!

enjoy.

As a temporary measure, and if you have a socket set with 12-cornered sockets (or some ring spanners likewise), see if any of them is a close fit. Not ideal, because the angles in the sockets/spanners are obtuse, so really heaving on them will round over the corners of the square bolt heads.

As an aside, I have a "four way" toolpost with square headed bolts which I use occasionally instead of my QCTP. I found that a plumber's four-armed spanner thingy with a different socket on the end of each arm has a square socket which is a perfect fit.

Andy

They have to draw a line somewhere Geoff. Me, I'd open it up and clean the switch with meths or a drop of servisol (if I still had some). It's probably only a slight build up of oxidation.

Neil

They have to draw a line somewhere Geoff. Me, I'd open it up and clean the switch with meths or a drop of servisol (if I still had some). It's probably only a slight build up of oxidation.

Neil

Geoff,

The excell is supposed ot take special filing machine files 4 in long with teeth in the opposite direction to normal files so they cut on the downstroke. They have a 1/4 or 1/8 round tang. They are no longer made and stocks all used up so it is luck to find some in a car boot sale. You will have to grind part of the file to adapt it. Since the files need to be parallel not tapered the only files that come near still in production are chain saw sharpening files – not suitable for our current job.

Search the web for die filer under the following mfr names as they are all the same basic design:
Oliver
Milwaukee Milwarkee
Harvey Butterfly
Harvey model B16