Material hidurax, 1 6a/13a to dtd 900/4805, elliott bros. Ltd; o/a lg 1.615 to 1.635 in.; largest shoulder diameter 0.990 to 1.010 in. Flatted two places to a w. Of 0.875 in.; internal thd end diameter 0.4056 to 0.4059 in., thds 1/4-20 unc-2b; external thd end diameter 1/2-20 unf-2a, w/ctr drilled hole bs3
