ISO3290

The steel balls produced by Zhongrui comply with a number of international standards (ISO 3290, DIN 5401, JIS B1501). In addition to manufacturing according to international standards, we can also develop and manufacture products that are most suitable for customers according to customers' special requirements.

Noun description

series	The precision of the steel ball is represented by numbers, the smaller the number, the more precise
Basic diameter	A number used to distinguish the size of a steel ball. The basic diameter is obtained by measuring the distance between two planes in parallel contact with the steel ball
The average diameter	The arithmetic average of the maximum diameter and minimum diameter of a steel ball
Average batch diameter	The arithmetic average of the average diameter of the largest steel ball and the average diameter of the smallest steel ball in the same production batch
Batch diameter tolerance	The difference between the average diameter of the largest steel ball and the average diameter of the smallest steel ball in the same production batch
Diameter tolerance	The difference between the maximum and minimum diameters of a single ball
Roundness	The maximum value of the difference between the radius of the smallest spherical surface on the surface of the steel ball and the radius of each point on the surface of the steel ball is the roundness of the steel ball
Surface roughness	Different grades of steel balls have different surface roughness ranges, please refer to the attached table of grades and tolerances
hardness	It can be divided into two testing methods, spherical hardness and flat hardness, please refer to the attached table of hardness and crushing value
carburization	The distance from the surface of the steel ball to the point where the hardness of the center is RC 50 is the carburizing depth, which is only suitable for heat-treatable steel

Series and tolerance

unit	VDS	W	VDL	Ra
3	0.08	0.08	0.16	0.010
5	0.13	0.13	0.25	0.014
10	0.25	0.25	0.50	0.020
20	0.5	0.5	1.0	0.032
40	1.0	1.0	2.0	0.06
60	1.5	1.5	3.0	0.08
80	2.0	2.0	4.0	0.1
100	2.5	2.5	5.0	0.1
200	5.0	5.0	10	0.15
300	7.5	7.5	15	×
500	12.5	12.5	25	×
800	20	20	40	×
1000	25	25	50	×
2000	50	50	100	×