When I bought my Bison 6 1/4" 4 jaw chuck about 15 years ago, they told me there were two grades, production and precision. The precision grade was about 20 percent higher cost. I bought the higher grade and am quite happy with it. You might want to ask them about this.
I like the 4 jaw since you can put round or odd shaped parts in it. Also, you can eliminate the runout on round parts which you can't on a 3 jaw scroll chuck. |