Undoing a castellated nut!

Well a little different to the title. I am dismantling and refurbishing an old Herbert High speed drill. There is a brass cover over the top of the top quill bearing. It is mounted on a brass flange, which has 4 neat squares cut out and which are distributed at 90 degrees to each other. Hence my very poor description of it as a castellated nut!

Now I am assuming these squares are to take a form of spanner rather like a C spanner, but with square rather than round pins. I am curious as to what such a spanner would be called, or do C spanners come with square as well as round pins?

I am assuming that this dome needs to unscrew to get at the bearing hence my query. There is no problem with fabricating a "spanner" to fit, Not sure if I should make a C spanner type tool or to make a socket to match and use a Tommy bar.

Andrew.

If you have the space to use it ... I would make the spanner as a plate with pins, and with a square hole at the centre, to match your favourite socket-set drive.

MichaelG.

I hope you can see whether the thread is left or right handed. Both of the mills I have dismantled had left hand threads.

Depending on the access, if you can reach it from above, then a tube with simple cutouts at the end would do.

A photo would help?

Normally a Castle nut socket would be used for what you're describing

Yes - the sort that looks like a hook with either a little square tang to fit rectangular slots as on your drill, or a pin to engage radial holes, is called a C-spanner.

The sort used on angle-grinders is more often called a Pin-spanner.

The tubular spanner Old Mart suggests, with square tangs left by cutting away the intervening steel, is a well tried-and-tested alternative for where the face of the nut is fully accessible. Usually, its top end is cross-drilled for a tommy-bar.

Hi there!

I think the nut Andrew is describing is classed as a lock nut (We also called them SKF nuts) which were widely used on our machinery at work. We made our own box spanners from steel tube to tighten/loosen them. They used a tab washer to lock them.

https://www.skf.com/webpim/0901d1968080a151/png/0901d1968080a151.png

As opposed to a castellated nut.

https://www.modeltford.com/i/d/2931491l.jpg

Pete

I think what Morty is describing is more likely than a castle nut, you'll need an axial lock nut socket if he's correct, easy to make your own.

Pics. We need pics.

Could use a regular C spanner if there is access. Or cut tangs in a socket or tube spanner as suggested. Or hammer and brass drift. All depends on exactly what it is and where it is located.e

(I'm usually the next bloke over on the far right going "It's a football, only hot and steamy and a bit sort of squishy."

Edited By Hopper on 11/03/2021 03:10:58

FYI elephants have internal testicles

Martin C

Hi Martin, thanks, I really wanted to know that!

Regards Nick.

a simple pin spanner will work in round holes as well a square cut outs,the advantage of square cut outs is the pins do not have to be very accurate regarding pitch. For the butcherand bodgers a square cut out is a lot easier to hit with a punch than trying to punch a round hole.