Taper Identification

[Andrew TinsleyParticipant @andrewtinsley63637]

I was sorting out the tooling that came with my Clarkson tool and cutter grinder. There was the normal 4MT  tool holder and a couple more taper toolholders. A quick measure, showed that the two tapers were identical and the toolholder was 4″ long. A 4MT taper would enter for about 0.5″! So I assumed it was a 3MT taper, wrong again, as the 3MT fell through the workholder!!

A quick calculation determined that the full taper angle was 1.03 degrees. Looking up standard tapers in Machinery Handbook showed that tapers were measured in taper per foot. Converting my measurements to the required taper per foot, showed clearly that the unidentified taper was neither Smart and Brown nor Jarno assuming I have not made an arithmetical error

So any ideas what the taper in the two workholders might be? This is really curiosity on my part as I will probably bore out the holders as needed.

Andrew.

P.S. The major diameter was 1.068″ and the minor diameter was 0.996″ length of workholder was 4″

[Chris CrewParticipant @chriscrew66644]

I also have a taper in the workhead of a J&S 1310 grinder that I have failed to identify, even through this site. It looks similar to a 30int but it certainly is not. I can’t recall the dimensions now having lost my notes but if anyone happens to know, or can confirm that J&S used ‘in house’ specials on their machines, it would satisfy my curiosity.

[old martParticipant @oldmart]

Are you aware that every Morse taper is a different angle? So much for inches per foot. There are many obsolete tapers out there waiting to confuse you. I was given a boxed set of die and tap holders with a MT3 taper and turned the taper into the biggest parallel shaft that I could manage so that both mills and both lathes could make use of them. They were donated by one of our volunteers to the machine shop.

[BazyleParticipant @bazyle]

I have a badly repaired and remachined Int30 that I took to be Int20 ‘cos it was so far below correct spec. In my research about 10 years ago I found reference to some T&C grinder being the only thing in common use that used an Int20, though it seemed a bit pointless to use that.

[Andrew TinsleyParticipant @andrewtinsley63637]

Hello Old Mart,

Yes I am certainly aware in the difference in taper angles, between the various Morse tapers. I was interested if anyone recognised the taper that I have, it certainly is an oddball, not one of the usual tapers that are relatively common. Like you I shall probably modify the tapers when I need something special. They are certainly of no use to me as is, I was just curious to see if anyone recognised the taper.

Andrew.

[Oily RagParticipant @oilyrag]

Could it be a Thiel or Deckel taper?

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