Tel: 860-571-3602  |  info@hartfordtechnologies.com
Tel: 860-571-3602  |  info@hartfordtechnologies.com

Ball Size, Grade and Tolerance Definitions

ABMA Std-10

Grade Sphericity Dia. Tolerance per Container/Lot Diameter Tolerance per Shipment Surface Finish
Inches MM Inches MM Inches MM Arithmetic Average
10 0.00001 0.0002 0.00002 0.0005 ±0.0001 ±0.00254 1
15 0.00001 0.0004 0.00003 0.0007 ±0.0001 ±0.00254 1
25 0.000025 0.0006 0.00005 0.0013 ±0.0001 ±0.00254 2
50 0.00005 0.0013 0.0001 0.0025 ±0.0002 ±0.0050 3
100 0.0001 0.0025 0.0002 0.0050 ±0.0005 ±0.0127 5
200 0.0002 0.0051 0.0004 0.0102 ±0.0010 ±0.0254 8
300 0.0003 0.0076 0.0006 0.0152 ±0.0015 ±0.0381 n/a
500 0.0005 0.0127 0.001 0.025 ±0.002 ±0.050 n/a
1000 0.0010 0.0254 0.002 0.051 ±0.005 ±0.127 n/a
2000 n/a n/a 0.005 0.127 ±0.005 ±0.127 n/a
Burnishing n/a n/a n/a n/a ±0.005 ±0.127 n/a

ISO 3290

Grade Sphericity Variation of Ball Diameter Variation of Ball lot Diameter Surface Finish
μ meters μ meters μ meters Ra
3 .08 .08 .13 .010
5 .13 .13 .25 .014
10 .25 .25 .5 .020
16 .4 .4 .8 .025
20 .5 .5 1 .032
24 .6 .6 1.2 .040
28 .7 .7 1.4 .050
40 1 1 2 .060
60 1.5 1.5 3 .080
100 2.5 2.5 5 .100
200 5 5 10 .150

DIN 5401

Grade Sphericity Variation of Ball Diameter Variation of Ball lot Diameter Surface Roughness
μ meters μ meters μ meters Ra
3 .08 .08 .13 .010
5 .13 .13 .25 .014
10 .25 .25 .5 .020
16 .4 .4 .8 .025
20 .5 .5 1 .032
28 .7 .7 1.4 .050
40 1 1 2 .060
100 2.5 2.5 5 .125
200 5 5 10 .200
500 25 25 n/a n/a

Ball Grade/Size Material Capability

Smallest Standard Size Smallest Standard Size Largest Standard Size Largest Standard Size Best Standard Grade Least Standard Grade
Stainless Steels
302/304 1.5mm 1/16″ 50.8mm 2″ 50 1000
316 1.5mm 1/16″ 50.8mm 2″ 50 1000
420 1.5mm 1/16″ 50.8mm 2″ 25 1000
430 1.5mm 1/16″ 50.8mm 2″ 100 1000
440c 1mm 1/32″ 50.8mm 2″ 10 1000
Other Materials
Chrome 1mm 1/32″ 50.8mm  2″ 10 1000
Low Carbon 1mm 1/32″ 50.8mm 2″ 100 1000
Brass 1.5mm 1/16″ 25.4mm 1″ 100 1000
Tungsten Carbide 1.5mm 1/16″ 50.8mm 2″ 10 100
Borosilicate glass 2mm 3/32″ 31.75mm 1.25″ 100 1000
Soda Lime glass 2mm 3/32″ 31.75mm 1.25″ 100 1000
Plastic
Acetal (Delrin and Celcon) 1.5mm 1/16″ 25.4mm 1″ G0 G3
Nylon 1.5mm 1/16″ 25.4mm 1″ G0 G3
Polyethylene 1.5mm 1/16″ 25.4mm 1″ G0 G3
Polypropylene 1.5mm 1/16″ 25.4mm 1″ G0 G3
PTFE (Teflon) 1.5mm 1/16″ 25.4mm 1″ G0 G3