A series of Black Granite Base Comparators designed to meet the requirements of both the large and small shop. These granite bases are Inspection Grade (Grade A, .0001"), offer a smooth surface, are nonabrasive and extremely hard for an accurate reference plane for work inspection. All granite bases come with a Certificate of Accuracy, traceable to N.I.S.T..
These 12" x 18" x 4" granite bases are supplied with a 1.25" diameter, 12" tall column; an indicator arm (rigid or with a fine adjustment knob), and a group 3 size dial indicator, 1.0" travel, .001" graduation, 0-100 dial reading, with a left hand lifting lever included.
Indicator arms are available in lug or stem mount. Indicator arms have a throat depth of 4"-5" and can be raised to a height of 7.5"- 9.5" depending on the type of mount used.
