Yoke/crane Alignment Tool Brownells.
.0005" Tolerances For Ultimate Accuracy
Because both Ruger® and S&W's lock at the front and rear of the extractor rod, even a slightly bent one can cause difficulty in lockup and will impair smooth operation, especially for double-action shooting. These tools will enable the gunsmith to more easily and precisely align the crane in a matter of minutes without "guesswork". Precision ground and hardened to within .0005" on all critical dimensions to assure the ultimate in accuracy. Full instructions with each tool. Hardened to Rc 52-54 to maintain exact specs.
Big Book Catalog, Issue:71, Page:479
Big Book Catalog, Issue:71, Page:480
SPECS: J - 2.6" (6.6cm) long; K - 3.17" (8cm) long; Ruger® - 3.025" (7.6cm) long. #1 for S&W "J" Frame (centerfire only); #2 for S&W "K", "L" or "N" Frame; #3 for Ruger® Speed-Six® and Security Six®. Shorten knurled end to fit 2½" barrel revolvers.