An odd grub

[Gary WoodingParticipant @garywooding25363]

[Gary WoodingParticipant @garywooding25363]

Has this grub screw got a special name, and any idea where I can get another?

It's thread size is M6 with a standard 3mm hex Allen socket.

[Mike PooleParticipant @mikepoole82104]

It looks like it is a special, if you have a lathe I would buy a standard grub screw and turn to match the one you have. Allen screws are not so hard they cannot be turned even with HSS tools. They are rather tough and getting a good finish may be a challenge.

Mike

[David George 1Participant @davidgeorge1]

I have seen similar but with a flat instead of a point but they were made from a standard grub screw just turned held in a holder in a chuck. The holder was taped and had a 4mm hole in the back to put an Allen key through and a shoulder on the outside to give stability and position when putting in to the chuck or collet.

David

Edited By David George 1 on 26/02/2018 16:05:35

[Clive Brown 1Participant @clivebrown1]

The flat ended type is called a dog-pointed grub screw. As said , this one looks like a special.

[Brian HParticipant @brianh50089]

The flat ended ones come in 2 flavours, known as dog and half dog.

Brian

[Gary WoodingParticipant @garywooding25363]

Thanks for the confirmation that it's most likely a special.

I'll have to machine a standard one.

[Neil WyattModerator @neilwyatt]

Looks like one for transferring hole positions.

http://www.arceurotrade.co.uk/Catalogue/Measurement/Punches-Scribes/Transfer-Screws

Neil

[MuzzerParticipant @muzzer]

M6 dog point grub screws here. You'd have to sharpen the point!

Murray

[OldironParticipant @oldiron]

Probably a special. A transfer screw normally has the pointy end machined onto a hexagon to facilitate insertion.

As here **LINK**

regards

[davebParticipant @daveb17630]

Posted by BDH on 26/02/2018 18:07:04:

The flat ended ones come in 2 flavours, known as dog and half dog.

Brian

WOOF WO

[Clive FosterParticipant @clivefoster55965]

There may be commercial sources for some sizes.

Back in the day at RARDE / DERA / DRA we used similar screws for adjustment / alignment purposes on internal workshop built lab, demo and prototype kit. These were fully blacked suggesting commercial made and there was a box or two of the supplied sizes keep in the section workshop so replacements were immediately available should one get dropped or lost.

Don't recall ever seeing the box(es) so I don't know if they were true off the shelf purchases or whether some genius had ordered several lifetimes worth from a commercial supplier to create a stash. Possibly a military thing. Being a MoD research establishment we would have access to such and been able to draw on military stores if needed.

Surprising amounts of specialist, low production but still commercial, stuff out there if you know the names, suppliers and the correct masonic handshake to get in.

Clive.

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