Made of well selected marble stone. Good quality and high accuracy with very competitive price. Standard size in stock

Black Granite Straight Edge

Fot inspecting the straightness and flatness.black granite straight edge

Granite straightedges purpose:

Measurement the workpiece of straightness and flatness and equipment installation,workface of the machine tools ,guide and the straightness and flatness of work precision.The material is the Jinan Black Granite,the granite straightedges is black shine,compact structure,uniform texture,good stability,high strengh and hardness,the granite straightedges of precision standard tools is made by natural stone,it's good standard to the instrument,precision tools,inspection of machine parts,especially use in measurement of high precision.

the granite straightedges character and advantage:

1.The rock through natural time,uniform texture,swell factor is so small,Internal stress disappear completely,no change shape,so it's high precision

2.Good rigidity,high hardness,strong wear resistance.

3.no Afraid of acid and alkaline liquid material erosion, and will not rust, do not need oiling, no easy to stick dust, maintenance, easy maintenance, long service life.

4.No scratches, no be prevented by constant temperature,it can keep precision measurement in constant temperature.

5.no magnetization ,can move when measuring,no dull sense,no wet influence,good flatness.

Precision:according to the national standards measurement examination regulations execution:

Beeline tolerance of working surface (μm)		Parallelism tolerance between the upper and lower measuring surfaces (μm)		Perpendicularity between side & measuring surface(μm)
grade00	grade0	grade00	grade0	grade00	Grade00	Grade0
400×60×25	1.6	1.6	2.4	3.9	8	13
630×100×35	2.1	3.5	3.2	5.3	10.5	18
1000×160×50	3.0	5.0	4.5	7.5	15	25
1600×250×80	4.4	7.4	6.6	11.1	22	37
2000×300×100	5.4	9.0	8.1	13.5	27	45