What Jacob's Taper Drill Chuck To Purchase?

[Pmedic828]

I am the wife of one of your members and I want to purchase a new Drill Chuck for my husband's mini mill / lathe because the old Chinese chuck won't always tighten and the key is very sloppy. I would like to get a keyless chuck and a machinery place has an ad for "any Jacob's chuck for $95" They list hat they had a JT2, JT33, JT6 chuck but the specs were all the same - 1/32 to 1/2 holding capacity. My question is if they sell these 3 different types of mount chucks, which one would be better. Are they all the same chuck but just have different tapers or is one type of chuck better than another - I will be ordering 2 chucks, one for R8, and one for MT3. Your help would be appreciated and thanks for teaching my husband machining - something he always wanted to try and now can enjoy as he is disabled and retired.

 

[dlane]

Pretty sure Jacobs chucks are all made in China nowadays , hard to say which Chuck would fit his needs the best. Personally I would want one that closes smaller than 1/8" on a mini mill.
the JT taper mounts Chuck to arbor , the MT taper mounts Chuck and arbor to machine
Sorry I couldn't be more help

 

[royesses]

The standard chuck on the Sieg/Harbor Freight R8 mini mill is a Jacobs JT-33 taper on an R8 arbor. The The 3MT mini mill uses a JT-33 Taper on a 3MT arbor. The chuck range is 7/64 to 1/2 inch capacity, as per the mini mill operators manual.

 

[joshua43214]

I don't think one mount is better than the others. Never understood why they have so many tapers for the same size chuck. I believe JT33 and JT6 are the most common for chuck under 3/4". I seem to have more JT33 than any other.

 

[RJSakowski]

Select the 3MT and R8 adapter first, then get chucks to fit. The JT6 and JT33 are very similar in size and will work well with a 1/2" chuck. The JT2 is slightly smaller and better suited to a 3/8" chuck.

 

[mksj]

I prefer to get ones with the chuck and shank are integral (1 piece), seem to be more accurate. Not impressed with the newer Jacob's chucks sourced from China.
Something like the Shar's premium line are similarly priced with an integrated R-8 or MT-3 shank, although I have not used them.
http://www.shars.com/company/online-catalog?p=124

I use a Z-live integral MT3 5/8" chuck on my lathe and am very happy with it. I only see the 1/2" listed at the site, but can call them if 5/8" is available.
http://zlivecenter.com/drill-chuck/...drill-chuck-morse-taper-3-integral-shank.html
http://zlivecenter.com/drill-chuck/...-2-keyless-drill-chuck-r8-integral-shank.html

 

[mikey]

Mrs. Pmedic, you are the first wife I've seen come here looking for advice about a gift for her husband! I'll let the others give the advice but wanted to tell you that this is a truly wonderful thing you're doing. It says a great deal about you, and him!

 

[oldboy1950]

+1 what mikey said, good luck to you and your husband.
Dan

 

[Tozguy]

If the objective is to replace the 'old' chuck with a new one, why not just get one with the same taper as the old?

When a chuck is listed as having a choice of tapers, it is basically the same chuck. The choice of tapers is to allow us to pick one that will fit on the equipment that we already have.

To mount the Jacobs chuck on a lathe or mill which has an R8 or MT3 spindle, an adapter is required with a R8 taper on one end and a JT taper on the other to take the chuck. If you are buying both an adapter and chuck then the choice of Jacobs taper is yours. M. Sakowski summed those up very well in post no. 5.

If the Jacobs chuck comes already with an integral MT3 or R8 mount as mentioned in post no. 6 then adapters and JT tapers don't apply.

 

[maker of things]

Sorry the pictures are not to scale. If you want to buy the adapter and drill chuck separate, just make sure the JT # is the same on both the adapter and chuck and they will fit together.

R8-JT__ adapter Or MT3-JT__ adapter



Keyless drill chuck with JT__ taper