4-jaw chuck needs some kind of tool to adjust

[LittleWatchShop]

Here is a 4-jaw chuck I recently acquired as part of a lot.  The jaws need a tool that has a square socket and small diameter to fit in the hole.  What would you call this tool?  Where would I find it.  I guess I could try to make it.  But, I dont want to. The chuck is made by HB Dale.

[HectorLooi]

I simply used a Philips screwdriver and ground the tip flat. Works quite well.

[LittleWatchShop]

Just now, HectorLooi said:

I simply used a Philips screwdriver and ground the tip flat. Works quite well.

Hmm, I am having a hard time visualizing that. The tool needs to have a square recessed region to go around the square post, no?

[HectorLooi]

[Kalanag]

You seem to need a „square key“. What are the dimensions of the square?

 

Edited April 21 by Kalanag

[Michael1962]

The key is quite simply called a chuck key. As you can see above, they can be either male or female.

Mostly male on larger industrial lathes.

[oldhippy]

You could use a clock key if you cant find the correct chuck key

[LittleWatchShop]

7 hours ago, HectorLooi said:

Ahhh. Yours is a girl, mine is a boy.

The square post is 3mm x 3mm. The body of the tool must have a diameter less than 5mm...maybe less.

Clock key is a good idea.  However, the body will be too big, so I will have to turn it down.

[oldhippy]

Google chuck square keys female then images.