4 jaw self centering chucks

[David S Newman]

In the 1960s I purchased a Rohm (German) 4 jaw self centering chuck and over the years have found this so convenient as it will accurately hold both square and round stock, why are these 4 jaw chucks so scarce as to me they are so much better? Don't know if they are still available, I don't think the extra jaw would put the price out of bounds.

This chuck of mine has been in constant use and still runs to a couple of thou. if I were starting a home shop again I would definately invest in another. David

[uncle pete]

Dave,
Bison makes them as do a lot of other manufacturers, Agree about how usefull they are.

Pete

[philbur]

http://www.workholding.com/FINDSELFCENTERINGCHUCK.HTM

Phil

[David S Newman]

So other than price why would anyone buy a three jaw in preferance to a four jaw ? David

[airsmith282]

So other than price why would anyone buy a three jaw in preferance to a four jaw ? David

my lathe came with a 3 jaw and i like it but i now have to have a 4 jaw do to the stuff ill be getting into next but it is possible to hold square in a 3 jaw but a 4 jaw is the best to use self centering is ideal if you need dead on center but other wise independent is the better way to go so i have been told so ill be getting both and use the one i need first the most and then use the other as needed,

[David S Newman]

my lathe came with a 3 jaw and i like it but i now have to have a 4 jaw do to the stuff ill be getting into next but it is possible to hold square in a 3 jaw but a 4 jaw is the best to use self centering is ideal if you need dead on center but other wise independent is the better way to go so i have been told so ill be getting both and use the one i need first the most and then use the other as needed,

Really don't see how you could hold square stock in a three jaw chuck to run concentric ?? Dvid

[Limy Sami]

Really don't see how you could hold square stock in a three jaw chuck to run concentric ?? Dvid

Make a split bush with an ID of across corners measurement of stock.

Re 4 jaw and round bar ;- it's the milking stool principle, not all 4J self centering chucks close that accurately

[philbur]

It seems to me that a worn or badly made 3 jaw SCC will always hold on all 3 jaws. But a 4 jaw SCC of the same condition might not hold on all 4 jaws. It's the 3 leg table versus 4 legs principle.

If this is correct then buying a cheap 4 jaw SCC might not be such a good idea.

Just a thought
Phil

So other than price why would anyone buy a three jaw in preferance to a four jaw ? David

[SDL]

So other than price why would anyone buy a three jaw in preferance to a four jaw ? David

To hold Hexagon?

Steve Larner

[gary hart]

Other then real small hex stock a 4 jaw self centering chuck will hold hex stock centered.