|2495 forum posts|
What’s the point of the JT2 S (short) taper? One of my chucks has it but I can’t find anyone that actually makes an arbor for it! Even Jacobs themselves don’t seem to make one. Yes I know a JT2 fits but it’s not very elegant and wastes space.
|Michael Gilligan||26/09/2019 16:45:06|
15482 forum posts
I think you may have answered your own question, Vic
The purpose of a short taper is to minimise the space occupied,
|Clive Foster||26/09/2019 17:36:07|
|2157 forum posts|
I'd always understood that the JT2 S was primarily intended as as male taper for drilling machines. Presumably exploiting the shorter body and shorter taper in the design of the machine to gave a greater distance between drill and table for the given overall size.
The slightly smaller diameter allows a 14 mm Ø spindle to be used whilst the full size version needs either 9/16" or 15 mm Ø.
Overall it seems an awful faff to save 1/8" in length. But sizing of Jacobs, like Morse, tapers is somewhat less than logical.
However according to Yukiwa Seiko, a Japanese maker of drill chucks and other tooling, **LINK** :-
JT2S is a short type of Jacobs taper No.2. The taper angle is the same as JT2, but the taper length is a little shorter than JT2. As the difference is just the taper length only, it is possible to mount a JT2S drill chuck on a JT2 arbor. Generally, JT2S taper is usually used in Japan while JT2 is popular in U.S.
So the preference may be largely geographical these days.
|2495 forum posts|
Thanks Clive. I won’t be going to Japan to get an Arbor!
It still begs the question, why do manufacturers make chucks you can’t get the correct arbor for.
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