# Deciding Between Bison & TMX 6-jaw chuck



## erikmannie (Jan 1, 2022)

Please help me decide on which brand, and let me know if I missing anything.

I currently own a few Bison & TMX chucks; I love them all. I am a little partial to TMX because the chucks are usually drop shipped directly from TMX in MA. As far as I know, Bison products *may be* drop shipped directly from OH.

The reason that I would like drop shipping is so that I don’t get somebody else’s problem/return/scratch & dent.

Anyway, I am either going to get a TMX 6-jaw chuck with a TMX adapter *or* a Bison 6-jaw chuck with a Bison adapter.

They are both the same diameter at 12” (bigger is better!). Weight is not a problem (I have a tool post crane). I need maximum gripping diameter. Price is less of a concern than, say, quality & specs.

Here is the TMX lineup:









						TMX 12" 6 Jaw Self Centering Manual Chuck Set Tru Plain Back 3-868-1200P
					

TMX 12" 6 Jaw Self Centering Manual Chuck Set Tru Plain Back 3-868-1200P




					www.smalltools.com
				




and









						TMX Set Tru D1-6 Adapter Plate 3-875-126P for 12" Chucks
					

TMX Set Tru D1-6 Adapter Plate 3-875-126P for 12" Chucks




					www.smalltools.com
				




To be continued…


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## erikmannie (Jan 1, 2022)

Here is the Bison lineup:









						Bison 12" 6 Jaw Self Centering Manual Chuck Set Tru Plain Back 7-868-1200
					

Bison 12" 6 Jaw Self Centering Manual Chuck Set Tru Plain Back 7-868-1200




					www.smalltools.com
				




and









						Bison Set Tru D1-6 Adapter Plate 7-875-126 for 12" Chuck
					

Bison Set Tru D1-6 Adapter Plate 7-875-126 for 12" Chuck




					www.smalltools.com


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## erikmannie (Jan 1, 2022)

Here is one side by side.

TMX:




Bison:


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## erikmannie (Jan 1, 2022)

Here is another side by side:

TMX:


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## erikmannie (Jan 1, 2022)

Bison:


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## erikmannie (Jan 1, 2022)

I see that the TMX max RPM is 1900, and the Bison max RPM is 1500.

For the TMX chuck, this link has more detailed info.





__





						3-868-1200P   - 6-Jaw(2Pc) SET-TRU™ Forged Steel,PB,12in - Toolmex Industrial Solutions
					

3-868-1200P 6-Jaw(2Pc) SET-TRU™ Forged Steel,PB,12in, Toolmex Industrial Solutions




					www.toolmex.com
				




Here are gripping ranges in inches for the TMX:


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## erikmannie (Jan 1, 2022)

I will be using this chuck mostly for making pipe welding coupons, and it is most efficient to maximize the diameter & thickness of the pipe (more room for welding deposit).

That is, a 1” Schedule 40 pipe welding coupon doesn’t take too long to use, but a 10 or 12 inch pipe welding coupon will keep a guy (or gal!) busy for awhile.


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## erikmannie (Jan 1, 2022)

Here is the manufacturer page for the Bison chuck:

Scroll down to the bottom:





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						Bison
					






					bison-america.com
				




and



			https://bison-america.com/pdf/Chapter_1/Specs_1_1.pdf


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## mikey (Jan 1, 2022)

If you're going with that much money on a 6 jaw, why not go for an SCA chuck? Probably one of the finest chucks made anywhere (SCA is made in Sweden), here is a new one on eBay. SCA chucks are on par with other top tier chucks like Pratt Burnerd and Rohm and I would definitely consider one.


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## erikmannie (Jan 1, 2022)

mikey said:


> If you're going with that much money on a 6 jaw, why not go for an SCA chuck? Probably one of the finest chucks made anywhere (SCA is made in Sweden), here is a new one on eBay. SCA chucks are on par with other top tier chucks like Pratt Burnerd and Rohm and I would definitely consider one.



Thanks, I checked it out. I can’t believe how many chucks that eBay seller has listed!

The 12” SCA chuck is a plain back. I could not find a D1-6 adapter on Google.


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## Beckerkumm (Jan 1, 2022)

When I talked to the guy at Ajax tool he said the two chucks were generally fairly equal and interchangeable.  The Bison backplate can be used with a TMX and vice versa.  His take was that Bison quality was slightly more consistent than TMX but didn't recommend a clear winner.  He was willing to discount the Bison backplate a little more so the pricing was close enough I went that route ( I had found a NOS Bison set Tru for a good deal so I only needed the backplate ).

I don't know if the centering lugs are the same on both.  The Bison 6" has set screws that are not equally spaced.  I don't know about the 12" or TMX but equally spaced screws are easier to adjust.  Dave


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## Badabinski (Jan 1, 2022)

I'll add that I've been absolutely pleased with my 8" Bison 6 jaw chuck. The sucker has some gravity, but the runout is fantastic. I managed to find a brand new Bison chuck for less than a TMX which is why I went that way.


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## erikmannie (Jan 1, 2022)

@Beckerkumm 

@Badabinski 

How are you guys finding new Bison chucks at a discounted rate?!


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## Badabinski (Jan 1, 2022)

I guess I must've just gotten lucky on the EvilBay. It looks like I bought my Bison chuck from Ajax Tool, and from what I recall it was like $200 cheaper than the TMX 6 jaws listed on KBC. Still not a cheap chuck (I paid $1500 for it), but it's been a joy to use. Had to machine my own backplate because there are no set-tru compatible backplates for 1¾"-8 threaded spindles, so I didn't have to buy an expensive D1 adapter (instead, I got to spend like 12 hours turning down a massively oversized piece of ductile iron).


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## mksj (Jan 1, 2022)

I also spoke to Ajax Tool when I purchased my set-tru 5C from them, similar discussion to above, specific to the 5C chucks I feel the Bison is a bit better as to minor issues. That being the case, when you get into the higher end forged steel body chucks they tend to be comparable between Bison/TMX, many of the chucks dimensionally are the same and the back plates are interchangeable (and also with some of the Gator back plates which are copies of the Bison). One other chuck to through into the mix is PBA, the ones still made in the UK not the lower priced ones under the Atlas branding that are now made in China.
PBA 12" 6 Jaw SETRITE Lathe Chuck 1226300


			PBA 12" 6 Jaw SETRITE Lathe Chuck 1226300
		


Close up pictures of the Bison 12" 6-Jaw SET-TRU Scorll Forged Steel Lathe Chuck








						Bison 12" 6-Jaw SET-TRU Scorll Forged Steel Lathe Chuck-.0004" TIR, w/Fine Adj.  | eBay
					

Find many great new & used options and get the best deals for Bison 12" 6-Jaw SET-TRU Scorll Forged Steel Lathe Chuck-.0004" TIR, w/Fine Adj. at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




I own the 6.3" PBA, it is very nice, but in this range I do not feel their is a best chuck among those we are discussing, they are all very good. I own two Bison and the PBA, all are top notch. Another individual I know bought the TMX 12" off of eBay as NOS and it was beautiful. Personally I would not want to be spinning this size chuck above 1500 RPM, if you are doing large diameter work you should be well below this. Also the TMX chuck is listed as 1500 RPM maximum on the chuck.

I would probably be in the Bison or PBA camp, as opposed to TMX. I just find the fit an finish a little better, but performance wise no difference.


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## erikmannie (Jan 1, 2022)

@mksj 

I was looking at PBA (4J) chucks awhile back, & one chuck I looked at was made in Spain! I have nothing against Spain, of course. I studied there & my wife’s family is from Spain, but I thought it was odd that an English company would outsource manufacturing to the mainland. 

I’m sure the quality control is up to spec & all that. I would imagine that the labor is cheaper.

My 5C collets are made in India by Crawford (an English company). Apparently the labor costs in the UK have the manufacturers looking elsewhere for workers.

In any case, I would be proud to own a PBA chuck.

As for the finish of TMX chucks, when I got my brand new, factory direct 12” 4J, I was surprised as to how poor the finish was. I remember saying to myself, “I hope that I never deliver a product like that to a customer!” They are obviously made for function and not beauty.


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## mksj (Jan 1, 2022)

These days many of the major brand machine names (as well as others) have out sourced production and/or offer a less expensive line, so one needs to be very careful in reviewing the details in any kind of purchase at this level. I still would recommend the Bison as a known quantity, I know multiple other people that have purchased chucks from them and they all worked great and fit/finish was very good. Granted chucks are made to work and last, not look pretty. Rohm is a brand that is uncommon in the US, but I do know of another person that bought their 6J set-tru style and thought very highly of it. He was able to get it *with a back plate* at less than 1/2 new NOS on eBay. The big issue with Rohm is that they are stupidly expensive, the back plates cost several times more than those from Bison/TMX, and nobody seems to carry their lathe chucks/back plate. So unless this eBay seller can hook you up with a back plate, I would pass. FYI, the Rohm is rated to 2300 RPM, scary....
Rohm 12.5" 6 jaw Self Centering adjustable lathe chuck 163774 ZSU HI-TRU








						Rohm 12.5" 6 jaw Self Centering adjustable lathe chuck 163774 ZSU HI-TRU $6580  | eBay
					

Find many great new & used options and get the best deals for Rohm 12.5" 6 jaw Self Centering adjustable lathe chuck 163774 ZSU HI-TRU $6580 at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




Also you need to look at the jaw types and width, I use a 4J 8" combination and the jaws are 0.2" at the tip so I can hold a wide range of stock. A 6J scroll is a matter of preference, they are more limited to thin stock as opposed to a daily driver, they also seem to be a bit worse with swarf/cleaning. Very expensive chuck if you only would use it infrequently. A friend in Tucson with the same lathe as yours went with the Bison combination chuck. Otherwise the Bison Set-Tru 6J if you can get a good price with a back plate. Probably call Small Tools and Ajax and see what they recommend and pricing. All my Bison chucks were sent from the US distribution center for Bison.


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## Janderso (Jan 1, 2022)

If all else is equal between the TMX and Bison, I would go with the Bison.
Consistency is a big deal.


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## Beckerkumm (Jan 1, 2022)

What are your reasons for the 6 jaw set tru vs a 4 jaw combination chuck in the 12" size?  I found a deal on a 6 jaw Bison and use it a lot but also found an old Union combo chuck and it is very handy.  My chucks are 6" so maybe not comparable.   Dave


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## erikmannie (Jan 1, 2022)

Beckerkumm said:


> What are your reasons for the 6 jaw set tru vs a 4 jaw combination chuck in the 12" size?  I found a deal on a 6 jaw Bison and use it a lot but also found an old Union combo chuck and it is very handy.  My chucks are 6" so maybe not comparable.   Dave



While making (4-10”) pipe welding coupons out of Schedule 40 pipe, my 4J independent deforms the pipe, as does my 3J scroll.


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## erikmannie (Jan 1, 2022)

@mksj 

I Googled “Bison combination chuck”, and I found something that said:

“Combine the advantages of a scroll chuck with those of an independent chuck”.

I will Google now how that would work.

I am going to guess a 4J scroll chuck that is Set-Tru.

Edit: My guess was wrong.

Here it is:






It has a scroll + you can adjust each jaw individually.


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## mksj (Jan 2, 2022)

The combination chuck is a bit of a strange duck for production type work, but they are more of a fusion of a scroll and a 4J independent. The scroll moves 4 bases for the jaws and then each jaw has an adjustment like an independent chuck. The scroll repeats to about 0.001", the independent allows a wide range of adjustment, and is great if you do odd shape size work or rectangular stock that I was doing the other day. It is very quick to change stock and dial down the TIR, and you do not have big knarly jaws like on 2 piece jaws. A set-true style will repeat a bit better, but is only designed for a very limited adjustment range (Like +/- 0.005") and is more a set and forget process. They take up extra depth and they are heavy, but they take a more standard back plate which is less expensive.


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## matthewsx (Jan 2, 2022)

erikmannie said:


> Thanks, I checked it out. I can’t believe how many chucks that eBay seller has listed!
> 
> The 12” SCA chuck is a plain back. I could not find a D1-6 adapter on Google.


I’ve bought from them before, definitely a legit operation.

John


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## erikmannie (Jan 2, 2022)

This web page shows 2400 RPM max for the Bison 12”:






						7-868-1200 Bison 12" 6-jaw Set-Tru Scroll chuck
					

Bison 12 1/2" 6-jaw forged steel body Set-Tru Scroll chuck, 2 pc. jaws, fine adjustment screws



					bisonchucksonline.com
				







My lathe doesn’t go that high.


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## Beckerkumm (Jan 2, 2022)

Sounds like the OP needs the six jaw but for those considering a combo 4 jaw, as Mark says, they are heavy and deep so the stock is held far from the spindle bearings.  You generally don't want to size those chucks at maximum swing as they are harder on the machine and the braking and clutch systems.  Dave


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## will.mcray (Jan 14, 2022)

Look at the weights as well. When I was looking at the 6 inch chucks, the Bison weighed 23lbs and the TMX is 29lbs. 


Sent from my iPhone using Tapatalk


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## erikmannie (Jan 16, 2022)

will.mcray said:


> Look at the weights as well. When I was looking at the 6 inch chucks, the Bison weighed 23lbs and the TMX is 29lbs.
> 
> 
> Sent from my iPhone using Tapatalk



Is a higher weight better?


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## mksj (Jan 16, 2022)

I do not see that weight would make one better than another, just easier to lift and get on the lathe. If you are only going to use the chuck infrequently, then you might consider a less expensive alternative and/or a 10" six jaw chuck. You will be limited with a 12" chuck as to the opening distance of the jaws, and may need to remove the gap, the through hole capacity is limited more by the D1-6 mount/spindle bore. 

A 12" Bison/TMX 6J is going to run you over 3K with back plate.  A 10" Bison/TMX 6J would be about 1K less, and going with something like the Shar's 10" 6J Set-tru would be 2K less. I recall a few other individuals that bought the new higher end Shar's 6J and they were very satisfied with it performance and accuracy. You can review the specs. below they have them in 10" and 12", they are semi-steel so the max RPM will be slightly lower, but if you are doing larger diameter work you would be nowhere near the maximum speed ratings. They are Set-Tru style so the TIR can be adjusted withing 0.0005", and more often the issue is clamping with 6J the diameter of the work piece will be out out of round more than that.

Somewhat in ascending cost, they will all hold stock pretty much the same. Bison 12.5" with back plate will be about $500 more than the TMX. Just would be a hard swallow spending so much on chuck, unless it was your primary chuck for the type of work you do. A 12.5" chuck on a 16" swing is a bit too big, and only advantage would be the chuck through holes is just over 3" vs. ~2.9" and you are still limited by the D1-6 back plate/spindle bore. I just picked the eBay sites, on Shar's often shipping is less through eBay, otherwise I would go directly to Small Tools or Ajax Ind.
Shar's 10" 6 Jaw SET-TRU Lathe Chuck .0005" with Fine Adjustment








						10" 6 Jaw SET-TRU Lathe Chuck .0005" with Fine Adjustment + TIR Certificate R[  | eBay
					

Find many great new & used options and get the best deals for 10" 6 Jaw SET-TRU Lathe Chuck .0005" with Fine Adjustment + TIR Certificate R[ at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




10" Bison 6 Jaw "Set Tru" Lathe Chuck + Adapter Plate








						10" Bison 6 Jaw "Set Tru" Lathe Chuck + Adapter Plate  | eBay
					

Find many great new & used options and get the best deals for 10" Bison 6 Jaw "Set Tru" Lathe Chuck + Adapter Plate at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




12-1/2" GATOR Lathe Chuck 6 Jaw TRU ADJUSTABLE FORGED +ADAPTER 1-103-1200








						12-1/2" GATOR Lathe Chuck 6 Jaw TRU ADJUSTABLE FORGED +ADAPTER 1-103-1200   | eBay
					

Find many great new & used options and get the best deals for 12-1/2" GATOR Lathe Chuck 6 Jaw TRU ADJUSTABLE FORGED +ADAPTER 1-103-1200  at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




Toolmex 12" Set Tru 6 jaw Lathe Chuck Made In Poland








						Toolmex 12" Set Tru 6 jaw Lathe Chuck Made In Poland  | eBay
					

Made In Poland Part # 3-868-1200P.



					www.ebay.com


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## erikmannie (Jan 17, 2022)

mksj said:


> I do not see that weight would make one better than another, just easier to lift and get on the lathe. If you are only going to use the chuck infrequently, then you might consider a less expensive alternative and/or a 10" six jaw chuck. You will be limited with a 12" chuck as to the opening distance of the jaws, and may need to remove the gap, the through hole capacity is limited more by the D1-6 mount/spindle bore.
> 
> A 12" Bison/TMX 6J is going to run you over 3K with back plate.  A 10" Bison/TMX 6J would be about 1K less, and going with something like the Shar's 10" 6J Set-tru would be 2K less. I recall a few other individuals that bought the new higher end Shar's 6J and they were very satisfied with it performance and accuracy. You can review the specs. below they have them in 10" and 12", they are semi-steel so the max RPM will be slightly lower, but if you are doing larger diameter work you would be nowhere near the maximum speed ratings. They are Set-Tru style so the TIR can be adjusted withing 0.0005", and more often the issue is clamping with 6J the diameter of the work piece will be out out of round more than that.
> 
> ...



Thanks for all the info, Mark! I am still shying away from mainland Chinese stuff, at least with welding & machining equipment.

I am getting closer to this purchase. Hopefully I will be pulling the trigger in February. I have some time off in March so it would be nice to spend some quality time with the new 6J.


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## erikmannie (Jan 28, 2022)

I ended up buying the TMX chuck & TMX adapter.

I have been checking on the internet every few days to see if there were any deals, and today I saw the chuck on eBay for $455.00 less than any price I had ever seen before. I jumped on it!

Sadly, there were no deals to be found on the adapter. Small Tools had the best price by far, & they did not charge me sales tax.


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## Watchwatch (Jan 29, 2022)

You will love that chuck. I have the 6”.

It’s been off my PM 1236T a handful of times in 2 years. I pulled it off a few weeks ago for cleaning and when I put back on, it was within .0002 TIR on a gage pin with no adjustments.

Tighten all 3 scrolls every time. My method is pressure on 2 scrolls and snug at a the 0 mark. You can fine tune TIR about .0005 by varying pressure on scrolls when needed.


Sent from my iPhone using Tapatalk


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## erikmannie (Feb 8, 2022)

I received the TMX 6J scroll chuck today via FedEx Freight. The only small issue that I had is that I need a 15mm hex key (or a hex key socket) to mount the chuck to the adapter plate. 

The box was a little damaged (see picture below). The FedEx Freight driver was very patient and professional in letting me inspect the merchandise. The chuck does has a small scratch (see photo), but I’m not worried about it.

I will post a picture of the chuck once I get my hex key here, and I can finish mounting it to the backing plate.

The adapter plate was delivered via UPS, and there was no issue.

I think the whole assembly (i.e. chuck + adapter) is 170 pounds.


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## woodchucker (Feb 8, 2022)

erikmannie said:


> I received the TMX 6J scroll chuck today via FedEx Freight. The only small issue that I had is that I need a 15mm hex key (or a hex key socket) to mount the chuck to the adapter plate.
> 
> T*he box was a little damaged (see picture below). The Fe*dEx Freight driver was very patient and professional in letting me inspect the merchandise. The chuck does has a small scratch (see photo), but I’m not worried about it.
> 
> ...


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## erikmannie (Feb 8, 2022)

Here is as far as I got without the hex key socket. Everything is such a mess because I am getting over a terrible flu bug!


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## erikmannie (Feb 9, 2022)

I had always been curious about how a Set-Tru chuck would float for the fine adjustment while bolted to the adapter plate. This link and document solves that mystery:



			https://www.toolmex.com/customer/docs/techdocs/Adj_set-tru_runout.pdf
		





Also beginning at the 3:30 mark in this video:


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## erikmannie (Feb 19, 2022)

I received this TMX 6-jaw chuck about  2 weeks ago, but I just got a chance to put it on today.

it is shown here with a length of 8” Schedule 40 on it:


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## erikmannie (Feb 19, 2022)

Here is a view from the side:


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