Standard Jaws are supplied with all Standard Jaw Vicmarc Chuck, but also available to purchase separately.
 
The sizes indicated on the drawing are when the jaws form a perfect circle.  VM120 and VM150 chucks provide approx. 48mm of expansion beyond these specified sizes. The Standard Jaws have an internal dovetail angle of 10 degrees for clamping and an external dovetail angle of 14 degrees for expanding.