3M PSA Diamond Cloth 5'' 1200 Mesh Adhesives rub a reference needle or

rub a reference needle or known gold sample beside the test streak

The Eschenbach 1645-4 is a 4X monocular replacement lens designed for use with compatible Eschenbach monocular frames

they are a reliable consumable for any jeweler's bench

Mild acid activator — removes oxides and micro-etches for strong adhesion of subsequent plates

SP 139) Number of Holes 31 Largest Hole 6 mm × 5

3M PSA Diamond Cloth 5'' 1200 Mesh Adhesives rub a reference needle orThe 3M PSA Diamond Cloth is a pressure sensitive adhesive wet dry abrasive designed specifically for working with materials rated harder than 7 on the Mohs scale. At 5 inches in diameter and rated at 1200 mesh, this diamond cloth features micron graded diamond particles affixed to a durable cloth backing using a tough resin bond. The result is a high performance abrasive that delivers consistent, refined results on hard gemstones, ceramics, carbide,