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New Jaws for Lathe Chuck

Don Kinzer

Cast Iron
Joined
Mar 18, 2002
Location
Portland, OR USA
I have a line on a used plain back lathe 3-jaw scroll chuck from a well-known and respected manufacturer, the type that has reversible jaws. The downside is that the jaws that come with it are special purpose jaws (soft jaws, I think, machined for a specific job). I suspect that installing new step-type jaws to the base piece is not as simple as bolting them in place.

Has anyone fitted new jaws to a chuck? What is involved in doing so?

3-jaw_chuck.jpg
 
A few years ago I purchased a set of hard top jaws for my 8" 6 jaw from Wholesale Tool (wttool.com) for a little over $300. You might try them. If it is an 8" chuck you have you might be able to use the jaws I removed from the 6 jaw. As I recall only 1 or 2 of the top jaws were damaged from a crash.
 
I purchased a set of hard top jaws for my 8" 6 jaw from Wholesale Tool [...]
Thanks for the tip. I was surprised (and pleased) to see that the top jaws are somewhat standard among several manufacturers including "Bergman, Bison, Buck, Cushman, Huron, Rohm, Forkhardt, Pratt Burnerd America, SCA, SP, W&S, Nobel and Yuasa".

Western Tool Standard Reversible Hard Jaws
Standard Reversible Hard Jaws

It is interesting that they call them "hard jaws" even though the description says that they are made from "1018 mild steel".

The chuck that I'm looking at is a 10" Bison.
 
The jaws/chuck you show in the first post are what's called "American" standard. I believe they are particular to the size of the chuck, with those for 6" a bit different (smaller) than those for an 8" chuck. If you buy top jaws in "American" for the size chuck you have they should fit fine.

The other standard is what I call the "Metric" standard and they have a serrated or v-notched interface which was never found on older US chucks.

Pete
 
The other standard is what I call the "Metric" standard and they have a serrated or v-notched interface which was never found on older US chucks.
Thanks. I have never seen that type. A search turned up this image of top jaws for a Kitagawa chuck. That seems to match your description.

serrated-top-jaws.jpg
 
Bison Lathe Chuck Hard Top Jaw for Scroll 1 in 3-Jaw 3 Piece Set 7-883-31 | eBay

that's about the best deal you will find for new hard top jaws.
It would have to be a pretty nice chuck to justify it.

The same company on their actual website has generic replacements for a little less, but if you are going to do it might as well get the real ones.

OTOH- if this is a typical used chuck with wear and you can get it cheap, here is another strategy....

BUy a cheap 3 jaw and steal the hard jaws off it to put on the Bison, then bolt soft jaws on the cheap chuck and use it for large diameter short work.
SHARS 1" 3 JAW LATHE CHUCK SELF CENTERING HARDENED FOR ATLAS NEW | eBay
 
Keep your eyes out on ebay for hard jaws. I've managed to pick up two sets for maybe $25 or less.

I would keep a set or two of soft jaws around, because they can be SO useful when having to do something repetitive.

A friend asked me to drill out some stamped sheet metal caps. I just bored the soft jaws out to the needed diameter with a shoulder to hold it straight so that it didn't wobble and parts change was about five seconds with the part dead nuts on.

US Shop Tools has good prices on soft jaws:
CHUCK JAWS - SOFT CHUCK JAWS, ROUND JAWS, HARD JAWS


Steve
 








 
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