K&T cat 40 tool holders

[Dave C]

My friend bought a K&T horizontal boring mill that supposedly has a Cat-40 spindle but cannot find tool holders that fit. He has bought several holders, but none of them will tighten up on a tool. I have not looked at it yet so wondering if anyone here knows if K&T has some secret means of getting the tool holder to hang onto a tool, or did he get some wrong info, and maybe the spindle is 50 taper? He also said there is a compression spring in the bottom of the socket, and no draw bar. I can't go there today, so fishing for ideas on what to look for. It's been years since I last ran anything that K&T made.

[Mcgyver]

If there is no drawbar that explains why they won't tighten up . A 50 taper looks massive compared to 40, will swallow it. A BT 40 is the same taper as the Cat but with metric thread.

I think we need some measurements

[tomato coupe]

My friend bought a K&T horizontal boring mill that supposedly has a Cat-40 spindle but cannot find tool holders that fit. He has bought several holders, but none of them will tighten up on a tool. I have not looked at it yet so wondering if anyone here knows if K&T has some secret means of getting the tool holder to hang onto a tool, or did he get some wrong info, and maybe the spindle is 50 taper? He also said there is a compression spring in the bottom of the socket, and no draw bar. I can't go there today, so fishing for ideas on what to look for. It's been years since I last ran anything that K&T made.

Your post is a bit confusing. It makes it sound like your friend expects a CAT40 tool holder to "squeeze" a tool like an R8 collet.

[Dave C]

There is no provision for a draw bar. The socket is a blind hole with a compression spring in the bottom. The more I thought about it, it would make sense that the spindle is equipped with a quick change socket, which may require compatible tool holders. I need to do some research.

[MattiJ]

Sounds like you need ”pull stud”

[Dave C]

Your post is a bit confusing. It makes it sound like your friend expects a CAT40 tool holder to "squeeze" a tool like an R8 collet.

Sorry for the confusion. I dashed off this post shortly after my friend called asking for help. He is not familiar with CAT 40 tooling, and his discription was not really clear. I should have waited until seeing the machine in person before posting the question.

[Mcgyver]

There is no provision for a draw bar. The socket is a blind hole with a compression spring in the bottom. The more I thought about it, it would make sense that the spindle is equipped with a quick change socket, which may require compatible tool holders. I need to do some research.

The modern standard quick change is via a pull stud installed in the drawbar threaded hole, but there are also an external quick change systems - i.e. Erickson quick change system. Perhaps its something like that