Before using it, be sure to check the stone plane for defects (surface curvature) in 6 places.
Lapping stone made of gabbro-diabase *. It is used for lapping the soles of planers, abrasive stones and other surfaces. Has a perfectly flat surface.
When working, use only abrasives for wet sanding on a paper or self-adhesive backing. Approximate dimensions: 280x150x25mm. The error is within +/- 0.07mm per 200mm.
Rubankov production (Russia)
Gabbro-diabase is a fine-grained full-crystalline volcanic rock, which, in its chemical and mineral composition, is quite close to basalt and most often has a black color. A characteristic feature of this stone is its high hardness and significant compressive strength. One of the distinguishing features of this natural stone is its relatively low silica content (about 45-52%). The color of the mineral can vary. There are specimens that are black, dark gray and even greenish-black in color. The stone has a diabase (also called ophite) structure, which is formed by chaotically located and elongated plagioclase crystals, the entire space between which is occupied by augite.