Real newbie question about ISO40 SK40 tapers

This question was raised last night as I disassembled and cleaned a boring head that came with my milling machine, my first milling machine, that I have never even run yet:



Never heard of the brand Magnadyne by the way, can't even find any info on it. But it raises some questions, how is this supposed to work without a draw bar?

I also went and looked at other tooling I had that came with the machine (an unknown collet holder and an ER collet holder). I note they have got draw bars so they can be held tight against the taper... But shouldn't they have some kind of matching drive lug to the machine spindles? The machine spindle looks like this (not my machine, but same style):





There are cutouts on both sides, I would assume a drive lug of some kind is meant to mate with that, I don't think the friction generated by a SK-40 taper is enough on it's own? But the other tooling instead has matching cutouts, basically they're both female. Is friction alone enough to lock it? Or should there be some kind of drive lug that goes in between the spindle and tool holder?

Or are these cutout meant for something else, like a spanner / wrench to help tighten the draw bar?

It would help if you posted the maker of your mill. Looking at your other threads I see that it is a Deckel FP2. To answer your questions:

Yes, in some instances the taper itself is enough to hold the tool. Deckel has a whole set of collets that do not use the lugs, just the taper. In instances where engaging the spindle lugs is necessary or desired there is a drive ring that connects the drive lugs on the tool holder with the spindle lugs.

Singer Werkzeugmaschinen GmbH

I made my own rather than pay that price, although I am sure it is quite nice.

What you are calling a draw bar is actually a pull stud. You can buy those from Singer as well, from the link above.

Teryk

Yes I wrote a bit shabbily in retrospect and yes it's an FP2 but I didn't think the brand was relevant, I googled SK40 tooling and most of them where like what I had, almost all "female".

Still, there is no way to fit a pull stud to the taper in question, the top has no provision for anything, there is only a small hole on the top that I don't know what it's for, maybe an old centering hole from when it was made.

I could probably modify it to accept a pull stud, I believe it is just an M16 thread. But curiously it did not come from factory set up for it. I wonder how they intended it to work?

Ah, a drive ring. I think I will make my own as well.
Mitnehmerring 1 mm NEU z.B. fur Deckel Frasmaschine | eBay

Is there anyone who might know what kind of taper the tool in my first picture is? It is not SK40 and I haven't found any indication of what it might be. No pull stud and no provision to fit one, no way to utilize a deckel drive ring, only a flat on two sides.

I am starting to wonder if this did belong ot the machine. It came with and was as dirty as anything else with the machine but I cannot understand how it would have been used.

I am thinking that to use this I will have to make a provision for a pull stud, but that should be doable on the lathe.

There are several 40 taper varieties in use. In all cases the taper is the same. The main difference is the draw bar provision and secondarily, the presence or absence of the drive lugs. The manual mill varieties have a short threaded neck. The Imperial version is called NMNT40 and uses a 5/8-11 thread. The Metric variety is called ISO40 and it has the neck threaded in M16. They are inter=changeable. The remaining varieties are meant for CNC machines with automatic tool changers. These types use pull studs. Similar varieties also exist in both 30 and 50 taper spindles. In all cases, it is the taper itself that provides the drive, not the lugs.

Well one piece of success, found the drive ring. It was in a box with an ER-32 collet holder. Though the drive ring does not fit over the ER-32 collet holder. It fits over all the other tooling that it says SK-40 on however. I have another collet holder with similar looking but shorter collets as well, the drive ring fits there too.