Would like some recommendations for high quality, domestic or european direct mount D1-3, 8", 4 indepedent jaw steel body chuck and D1-3, 6" set rite steel body (4000 RPM) chuck. Thanks!

Why would you want a set tru 4 jaw ?

I think he's asking about 2 different chucks - an 8" 4-jaw and a 6" 3 or 6 jaw scroll, adjustable.

I've had a lot of luck with the Bison brand chucks (Toolmex is the importer). Good quality out of the box, more expensive than 10 years ago but still very good value, decent price on the top jaws for the 3 jaw chucks. I haven't bought any of the direct mount 4 jaws but if they have the same quality as the 3 and 6 they'd be good value.

The only objection I have to the adjus-true feature on the Bison chucks is that the adjusting screws aren't in a 90-90-90-90 pattern but instead 60-120-60-120 (or something like that). There's always a little movement on the other pair when you move a set. (I'm not sure if that's a problem with the 6 jaw only, or the 3 and 6).

If you're not in a hurry you can find decent chucks on eBay. It's a little bit of a crapshoot but you'd likely be able to buy 3 chucks for the new price from a distributor. A bunch of 10EE tooling was sold last week, you should see most of it appear on eBay in the next couple of weeks.

Yes I was asking about two different D1-3 style chucks, 6" set true (which has a backing plate) and a 4 independent jaw 8" direct mount. Also would you suggest more than 3 jaws on a 6" set true if that was your only self centering chuck. Also could you give your opinions on quality, Bison, Pratt-Bernerd, Rohm & BTC. Any other quality chucks you might suggest looking at. Thanks

I've good experience with Pratt-Burnerd and Rohm, the chucks compare well with Bison, maybe a bit better. I've bought replacement parts from Rohm and found their US distributor (in Atlanta?) easy to deal with and the parts priced nicely. Pratt-Burnerd I haven't as much experience with and the parts I have obtained were not cheap.

I don't have any direct experience with BTC.

Plenty of other good chucks out there if you're looking at used stuff - most everyone likes Buck (before they moved production to Taiwan, mixed reviews after). Kalamazoo seems to be making chucks to the old Buck patterns. Kitagawa and Northfield make very nice chucks but out of my league and price range. If you can find a Cushman in good shape they're nice, the low scroll rate give you a good hold - but they're getting old now and showing their age.

As to a 6 jaw vs. a 3 jaw - a 6 jaw is nice if you're not going to use collets, it can be used to distribute gripping force. Nice when you're boring something thinwalled and don't want to end up with a trichordal hole.

In a 3 or 6 jaw chuck I like master jaws with top jaws - you can replace a mangled top jaw or bore out soft jaws for finicky work. They can also have a longer gripping area than regular jaws, that can be a plus or a minus. The master jaws are usually made for one direction only and so can take more clamping force than reversable plain jaws.

Don't be afraid to buy a 3 or 6 jaw chucks with any back on it, then find a D1-3 later and mate them up. You're going to have to face the backplate anyway to make sure that everything is good to go on your lathe and it's possible that you can find a great deal on a chuck with an oddball back and 'fix' it with a $75 backplate.

I got a direct-mount Cushman 6-jaw with my lathe, and have been very happy with it, regardless of its 70 years. I also bought an old american 8" direct mount with 2-piece jaws that I use only with soft jaws whenever I need precision or difficult holding.

My 8" 4-jaw is probably a Cushman, although any labels are long-gone. I don't see a good reason to spend a lot of money on a 4-jaw.

As you might be aware, the 4000 RPM requirement narrows the field of suitable chucks in the sizes you are seeking. Whatever make you get if you are going to use them at that speed a manufacturer's pedigree to that RPM is prudent. Many chucks in those sizes from quality makers are not rated to 4000 RPM.

If shopping for used chucks it becomes more difficult to be certain what one is getting.

The more-or-less standard EE chucks are:

1) Cushman 6" forged steel three-jaw scroll chuck with two sets of jaws (a variation with reversible top jaws is quite rare, in my experience), and

2) Skinner 8" forged steel four-jaw independent chuck, and also, later,

3) Buck (or someone's) 6" cast semi-steel three-jaw scroll chuck with adjust-true feature,

all in direct D1-3" mounts.

I find it useful to have two of the first, one of which is installed with inside jaws and the other of which is installed with outside jaws.

The direct mount D1-3 makes a shorter chuck protrustion from the spindle. But you can't have a Set-Tru with direct mount, it will have a back plate. The cushman 8" 4 jaw I believe reading was rated for 4K, not sure I'd be the operator at that speed. The Bison 6" 6 jaw cast body is 2500rpm, the forged is 3500 rpm. Best price new was from NE Brass and Tool, where these were purchased. I have an 8" 3 jaw Bison as well. Having taken both apart, the machining was nice, but a 10" Rohm was really nice, the scroll threads were polished, all bearing surfaces were glass smooth, the Bison had none of that. But the price is also not close.

"But you can't have a Set-Tru with direct mount, it will have a back plate."

True, but it is a purpose-built back, which is intended only for use with the parent chuck.

The Buck Set-True chucks have a back which is retained by the six outer cap screws which run all the way from front to back, on the outside of the chuck.

The front and intermediate halves are retained together by six cap screws which run from the front to the intermediate halves on the inside of the chuck.

In operation, you loosen only the six outer cap screws, then you operate the adjusters which are largish pistons which bear against the cylindrical boss which projects from the back into the intermediate half.

This concept can be implemented on some import chucks, particularly those which have front-loaded retention screws.

From what I have kicked around, I have had no noticeable problems with 8" 4 jaw chucks with back plates. I make my own back plates.
I have modified many plain back chucks, by front drilling them, makes for a nice clean installation.
The best 4 jaw chucks I have found are old ones with little use. My favorites are Skinner, Union, Cushman, ect.