Black Flat Granite Lapping Plate Measuring Tools

High precision granite surface plates can provide an accurate reference plane for work inspection and for work layout. The high degree of flatness, quality and workmanship also make them ideal bases for mounting sophisticated mechanical, electronic and optical gauging systems.

 
The hardness and stability allow accuracies within millionths of an inch. Along with the high accuracies, granite is rust-proof, non-magnetic, abrasive resistant, non wedging, wrap-resistant and easily cleaned. The granite used for surface plates has an excellent distribution of hard quartz which provides a smooth, long-wearing working surface.
Granite surface plates meet or exceed Federal Specifications DIN/876. Final inspection and calibration of every surface plate is accomplished by use of the Auto-Collimeter

Repeatability:

• Grade "B" Toolroom ± 100 Millionths
• Grade "A" Inspection ± 50 Millionths

Our granite surface plate refers to the advanced standards of the leading countries, and its flatness tolerance is in accordance with the JB/T 7975-1999 Surface Plate:

Grade 000 =1x(1+d/1000)/μm

Grade 00 =2x(1+d/1000)/μm

Grade 0 =4x(1+d/1000)/μm

Grade 1 =8x(1+d/1000)/μm

(d is the length of the diagonal)