COMBALLS GROUP.
Qingdao ,266061, China
http://www.comballs.com
Phone: +86 532 88235086;Fax:+86 532 83883615
sales@comballs.com

Steel Balls ISO3290 Standard

GB308-84 ISO 3290 - 1975 (E) Standard

 
 
VDws
Sph
Ra
  
Grade
Maximum Diameter
mm
Ball Dia. Variation
μm
Deviation From Spherical Form
μm
Surface Roughness
μm
  
3
12
0.08
0.08
0.012
  
5
12
0.13
0.13
0.02
  
10
25
0.25
0.25
0.025
  
16
25
0.4
0.4
0.032
  
20
38
0.5
0.5
0.04
  
28
38
0.7
0.7
0.05
  
40
50
1
1
0.08
  
100
all
2.5
2.5
0.125
  
200
all
5
5
0.2
  
Grade
VDwL
Lot Dia. Variation
μm
Gauge
Interval
μm
Preferred Gauge
μm
Subgauge
Interval
μm
Subgauge
μm
3
0.13
0.5
-5,-4.5,...,1,-0.5,0,+0.5,+1,...,+4.5,+5
0.1
-0.2,-0.1,0,+0.1,+0.2
5
0.25
 
-8,-7,...,-2,-1,0,+1,+2,...,+7,+8
 
 
 
 
1
 
0.2
-0.4,-0.2,0,+0.2,+0.4
10
0.5
 
-10,-9,...,-2,-1,0,+1,+2,...,+9,+10
 
 
16
0.8
 
 
 
 
20
1
2
-16,-14,...,-4,-2,0,+2,+4,...,+14,+16
0.4
-0.8,-0.4,0,+0.4,+0.8
28
1.4
 
 
 
 
40
2
4
-20,-16,...,-8,-4,0,+4,+8,...,+16,+20
0.8
-1.6,-0.8,0,+0.8,+1.6
100
5
10
-40,-10,...,0,+10,...,+40
2
-4,-2,0,+2,+4
200
10
15
-60,-15,...,0,+15,...,+60
3
-6,-3,0,+3,+6