Northfield Precision Inst. ST-1-6-1 Steel Jaws For Series 600 Chucks
.950" X 2.912" X .990" high
(4) .198" bolt holes on 1/2" centers
(3) 1/8" dia. pin holes on 1/2" centers
These jaws have been machined, see Pix.
1st step is .788"
2nd step is .897"
3rd step is .933"
4th step is .991"