Question about drill press chucks

[JeffG78]

My drill press is heavy duty and works well, but the chuck is a piece of crap and I would like to replace it. My question is about the taper. The drill press has an info plate on the front as shown.

I know the JT means Jacobs Taper, but what is the 2-1/2? I found a JT chart on the web and they list 0, 1, 2, 2 short, 3, 4, 5, 6, and 33. The only thing I can figure is that the tag means JT2 and 1/2" capacity, but it has a separate line on the tag for capacity and the JT and 2 are separated. I could always remove the chuck and take it in, but I'm curious about the info tag. The drill press is about 25-30 years old. It is a Majestic Tool Corp drill press, but internet searches reveal nothing about the company. I'm guessing it was a generic import brand name.

[Tom Slick]

I think you are correct, it should be JT2. it could mean 1/2" straight shank arbor to JT2. JT2 is very common and more then likely that is the chuck you need.

[Popeye]

I"m not a machinist but I've in buying drill chucks for my drill press and lathe I found out that both use an arbor with two tapers, one for the chuck and one for the spindle. Looking at the Grizzly site it appears that probably JT2 is the short taper on the drill press arbor, the long taper if you seperate the two is probably gonna be a MT. I'd take it out and take it into a machine shop and have them tell me. Pat http://www.grizzlyindustrial.com/pro...=drill%20chuck

[LCHIEN]

its a bit of a puzzle. The JT and 2 being separated seems like no accident, so it might not be a JT2. Maybe it means a Jacobs taper and a 2.5" stroke?

If you have calipers maybe you could measure the amount of taper. I'm sure there'a a table somewhere. Ah, here:
http://www.newmantools.com/tech/taper.htm

more useful info
http://www.beautifuliron.com/jacobs.htm

[JeffG78]

Update

Well, I finally had a few minutes tonight, so I removed the chuck and measued the taper. First, the drill appears to have a fixed male spindle, but how can I tell if it comes out? The chuck popped off without the spindle and the remaining part of the spindle has a collar just above the taper. The collar is tight against the drill press head telling me that there is no taper on the top of the spindle otherwise the collar would hit the head before the spindle would wedge in. Does this sound like the right thinking? The chart stated that some drill presses have fixed spindles and when fixed, they are usually JT-33.

Now on to the spindle taper... After measuring the spindle, the closest one is JT-6. Both the small end and the big end are slightly undersized when measured at the smallest point and at the top of the shiny witness mark and the length of the shiny part of the taper is 1.00" which matches the chart. When I adjust and lock the calipers to the JT-6 dimensions, both fit the spindle if I slide the calipers up about 1/8" from both the smallest point and from the top of the witness mark. No other taper on the chart is close to what the spindle measures.

Now I have to search to see if a JT-6 chuck is common or rare. If rare, it will likely be expensive and I will stick with what I have. I was hoping to find a keyless Jacobs chuck like what Woodcraft sells for less than $30.

Thanks all for your help.

[LCHIEN]

http://grizzly.com/products/G8582 $70

http://cgi.ebay.com/1-32-1-2-Heavy-D...QQcmdZViewItem ebay $25

keyed chuck
http://www.amazon.com/JT6-drill-chuc.../dp/B000HRZT70 amazon $30