Granite Machine Parts with high precision

Granite Surface Plates are used for precision gauging, inspection, layout and marking purposes. They are preferred by Precision Tool Rooms, Engineering Industries and Research Laboratories because of their following outstanding advantages.

No rust, no corrosion, relatively warp-free, no compensating hump when nicked, longer wear, smoother action, greater precision, non magnetic, less care after commissioning, lower co-efficient of thermal expansion and non glaring surface.

Salient Features :

Made from close-grained Granite having uniform color and texture having hardness between 5.6 to 7 on Moh's scale, sound and free from flaws fissures and large inclusions of softer minerals.
Made generally as per GB117-2015. Also available on request conforming to DIN-876-1972, BS-817-1988, JIS -B-7513 and US Federal specification GGG-P-463-C.
metallic threaded inserts, metallic T-slots, Plates with two or four ledges also can be supplied against specific request at extra cost.
Rexine cover provided for top working surface with each Plate.
steel stand with leveling screws are available on request at extra cost.
Granite Lapping Plates square and rectangular available on request.
Also available in Grade 00 as per DIN 876.
Sizes offered from 200x300mm to 8000x2000mm
Other sizes are also offered on request.

Physical Property of Jinan Black Granite:

Specific Gravity: 3.03 g/cm3
Shore Hardness: > 70Hs-80Hs
Tensile strength: 211Kg/cm2
Compressive Strength: 245-254Mpa
Linear Expansion Coefficient: 4.61´10--6/°C
Elastic Modulus: 30-50Gpa
Water Absorptivity: ≤0.13%

Product Application:

Mainly used to measure parallel and equal altitude of precision instrument, precision tool, mechanical component in modern industry and scientific research institutes.
We are able to manufacture the Granite Surface Plate with the good and stable flatness according to standard of DIN/JIS/GB.

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)