Starrett 657AA Magnetic Base Complete Set with Base, Upright Post, Rod, Attachment, and Two Snugs

Starrett 657AA Magnetic Base indicator holder is an all-inclusive kit for use with all Starrett test, back-plunger, dial, AGD, and miniature-dial indicators, as well as similar indicators from other manufacturers. The set includes a Starrett 657P magnetic base, a 657G upright base post, a 657S snug, a 657X rod, a 657Y indicator attachment, and a PT18724 snug. The 657P magnetic base is 1-15/16” x 1-5/8” x 1-7/8” (50 x 40 x 48 mm) and has a push-button on/off switch for one-handed operation. The base has three precision-ground, magnetic contact points to grip horizontally, vertically, and upside-down. The V-step holds the base to arbores, shafts, and other cylindrical items. The base has an additional 1/4-20 tapped hole on one side for mounting the post. The magnetic base has a non-skid, black wrinkle finish on all non-working surfaces. The base post is 3/8” (9.5 mm) in diameter and 7-7/16” (190 mm) long. The Starrett 57S and 58S snugs may also be used with this post (sold separately). The 657S snug has two 1/4” (6.3-mm) diameter holes and adapts the 196, 650, and 651 series dial indicators and the 657Y indicator attachment to the 657X rod. The 657X rod is 1/4” (6.3 mm) in diameter and 6” (150 mm) long. It accommodates the Starrett 708, 709, 811, and 711F series dial test indicators. The 657Y indicator attachment has a 1/4” (6.3-mm) outer diameter hole on one end, while the other end is threaded to fit the backs of all AGD indicators (Starrett series 81, 25, 655, and 656) and series 80 miniature indicators. The PT18724 snug has a 3/8” (9.5 mm) diameter post hole and a 1/4” (6.3-mm) diameter gripping hole to accommodate the 657X rod.