Drill Chuck Key Specification/Sizing

The only standard I know of is the Jacobs numbers. In the far left column of the chart below:

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=1703&PMCTLG=00

The chuck key for the 3/4 Jacobs chucks like the 18N or the 36 series is a K4. Good chance your Cardinal chuck uses the same key. Cost you about 10 bucks. MSC has them. $9.31 Picture from the online catalog at the bottom of this reply. Their retail arm, Enco, probably has it in their online catalog. Might be a different Enco part number but the Jacobs designation, "K4" will still apply.

http://www1.mscdirect.com/CGI/GSDRVSM?PACACHE=000000156551833

If you go to a business that sells supplies and tooling for machine shops an show them your chuck they will likely have a key that fits and if you have the chuck right there you can check it directly.

Ed Weldon

Ed, Thanks for all the info - will take some measurements when I get home... problem with the 'taking to a shop' option is that I live in Cyprus - there are some gems of specialist shops there who will dig out the most obscure part from their stores (if you are lucky) there just aren't very many of them and I've been to my favourites already...

Thanks for your help.

chosceng --- Try McMaster-Carr. They have a long history of serving a worldwide customer base for hardware not available in remote places and are highly experienced in the matters of currency and customs transactions for most nations.

http://www.mcmaster.com/#

In recent years they have bolstered their USA business in response to the disappearance of local industrial hardware businesses here as America has dismantled its industrial base. They have an excellent website they developed in large measure to serve the US customer base which supplements their hard to find hard copy catalog. My son, an engineer with a local company, reports that they are highly responsive to his orders for all kinds of stuff he needs for his projects. Email them to see what the shipping costs to Cyprus might be. You might be pleasantly surprised at the cost of sending such a small item.

Below is McMaster Carr's catalog page for chuck keys.

http://www.mcmaster.com/#drill-chuck-keys/=95rdeg

You may want to go through an effort to measure your drill chuck starting with the pin hole diameter and distance to the varying pitch line of the bevel gear. A Machinery's Handbook will be helpful in determining how to best measure the miter gear teeth on the chuck. Perhaps a cast replica will help. I strongly suspect the people at McMaster Carr will be ready to work with you on finding the right key once you show them the measuring effort you've gone through. They are that kind of company.

Good luck with this and if you can please tell us your experience with them; successful or not.

Ed Weldon

Most manufacturers seem to use there own standard for their chucks , sometimes you can find ones that are interchangeable, but on the whole it is pot luck, I even have a 1" Jacobs chuck with a Jacobs key that does not seem to work as well as it should.