Starrett 659A Heavy-Duty Magnetic Base Assembly Set, With Upright Post, Snug, Gauge Rod With Clamp, Fine Adjust, Thread Adaptor, Without Case

The Starrett 659A magnetic base assembly set is used to mount dial indicators for taking precise and repeatable measurements. The base has an on/off switch that releases the magnetic field when positioning the base. When turned on, the magnetic base has a holding power of 100 to 150 lb. The v-shaped base attaches to flat surfaces or round surfaces up to 5"/125mm in diameter. A threaded adapter on the base makes it possible to use Starrett Series 657 magnetic base posts and attachments. Both the upright post and gage rod are approximately 9-3/8" (238mm) long and 3/4" (19mm) in diameter. The post snug has two 3/4"/19mm holes that position the dial indicator at any height and vertical angle, and provides 360-degree rotation of the gage rod. The arm assembly can be finely adjusted to position the indicator as required. The set includes the magnetic base, upright base post, gage-holding rod with clamp assembly and fine adjustment, and a swivel post snug. Magnetic bases are magnetic fixtures commonly used in metalworking to hold dial indicators, and are also used in other fields, such as optics. Magnetic bases can assist the user with setting up a work piece in a milling machine, surface grinder, or other machine tool. The vertical post and rod in a magnetic base connect using swivelling connectors, or snugs. This allows free motion of the arm so that the dial indicator can be moved into position on the work piece. Many magnetic bases have a V-step, which is a V-shaped notch in the base for holding the base to arbores, shafts, and other cylindrical items. The magnetic base has a circular hole through the centre. A round permanent magnet is inserted into this hole, and a handle or button is attached to allow the user to rotate the magnet.