Thread: 4 jaw self centering is it worth buying ?

I haven't used one but they say they hold better because of the opposing jaws. And it sounds high quality so if the price was right, I'd go for it.

If the price is right then yes...

Apart from the possable holding advantage,what other benifit can you yourself see in it compared to a 3 jaw .

Originally Posted by pipeclay

Apart from the possable holding advantage,what other benifit can you yourself see in it compared to a 3 jaw .

well .another benifit I can see is that it can hold the work pieces that 3 jaws can't .
Cheers
Peter

So that would be square.
Wouldnt a 4 jaw serve the same purpose.

Peter, remember that a 3 jaw chuck will always grip apart, even if the material is slightly out of round but a 4 jaw self centring will only grip a part completely if it is perfectly round (or square) and the jaws are perfectly adjusted too. If you were gripping something soft or that would deform like tube this would not matter but if you had some black steel in it in a lathe you may find that one pair of jaws will grip but the other pair will not, resulting in the material clattering around in the chuck. Worse still, under cutting forces the material may start walking out of the chuck.
On a rotary table things would be slightly better but you would still not be holding material rigidly so chatter or movement could result.
Unless you were always going to be machining materials supplied to close geometry specifications or materials that would conform to the jaws I'd be going the three jaw route.

Michael

The only real advantage that I can see with a S/C 4 jaw is the increased gripping power of it over the S/C 3 jaw.

If I had a choice of only one chuck out of 3 jaw S/C, 4 jaw S/C and 4 jaw independant I would pick the 4 jaw independant everytime. They have the advantage of gripping power, versitility of holding various shapes and minutely adjustable for precision work.

It's just my opinion though. You might have a specific use for the 4 jaw S/C chuck.

I would buy it, My theory is you can't have too many tools..

Originally Posted by Michael G

Peter, remember that a 3 jaw chuck will always grip apart, even if the material is slightly out of round but a 4 jaw self centring will only grip a part completely if it is perfectly round (or square) and the jaws are perfectly adjusted too. If you were gripping something soft or that would deform like tube this would not matter but if you had some black steel in it in a lathe you may find that one pair of jaws will grip but the other pair will not, resulting in the material clattering around in the chuck. Worse still, under cutting forces the material may start walking out of the chuck.
On a rotary table things would be slightly better but you would still not be holding material rigidly so chatter or movement could result.
Unless you were always going to be machining materials supplied to close geometry specifications or materials that would conform to the jaws I'd be going the three jaw route.

Michael

Thanks Micheal and all other .
I think your explain is make a lot sense . I will pass this .
Cheers
Peter

I would not buy it. A self centering 4 jaw chuck is only used for holding precision ground round material. They are used where rigidity of the work piece is an absolute necessity. Look around and see how many workshops have one of these chucks. If the workpiece is not ground (perfectly round) then it will never hold in the chuck with all four jaws touching the job. One jaw will always be loose or not gripping. This does nothing for accurate work or good finishes. Don't buy it! It will become a white elephant very quickly.

Hi guy.
I decide to go for it ,so got it installed . so far I like it .
here is some pictures .
cheers
Peter