Available Grades and Tolerances

The following standard grades and tolerances conform to the International Standard as set forth by the ABMA/ANSI/ISO-3290
*Note Allowable Ball Grade Deviations High & Low are for reference only.

 

Standard ABMA/ANSI/ISO-3290 Grade Specifications

Grades Sphericity (Roundness) Allowable Lot Diameter Variation Allowable Ball Grade Deviations High & Low Max Markings Increments Surface Roughness (Ra)
  Inch µm Inch µm Inch µm Inch µm µ" µm
3 .000003 0.076 .000006 0.13 +/-.000030" .75 / -.75 .000010 0.25 0.39 0.010
5 .000005 0.127 .000010 0.25 +.000050 / -.000040" 1.25 / -1 .000010 0.25 0.55 0.014
10 .000010 0.253 .000020 0.5 +.000050 / -.000040" 1.25 / -1 .000010 0.25 0.78 0.020
15/16 .000016 0.406 .000032 0.8 +.000050 / -.000040" 1.25 / -1 .000010 0.25 0.98 0.025
20 .000020 0.507 .000040 1 +.000050 / -.000040" 1.25 / -1 .000010 0.25 1.25 0.032
24/25 .000024 0.609 .000048 1.2 +/- .000100" 2.5 / -2.5 .000010 0.25 1.57 0.040
40 .000040 1.01 .000080 2 +/- .000100" 2.5 / -2.5 .000010 0.25 2.36 0.060
48/50 .000048 1.22 .000096 2.5 +/- .000200" 5.0 / -5.0 .000050 1.25 2.76 0.070
60 .000060 1.52 .000120 3 +/- .000200" 5.0 / -5.0 .000050 1.25 3.14 0.080
100 .000100 2.54 .000200 5 +/- .000500" 12.7 / -12.7 * * 3.93 0.100
200 .000200 5.08 .000400 10 +/- .001000" 25.4 / -25.4 * * 5.90 0.150
500 .000500 12.69 .001000 25 +/- .002000" 50.8 / -50.8 * *
1000 .001000 25.4 .002000 50 +/- .005000" 127.0 / -127.0 * * * *
The following standard grades and tolerances are for Rockbit material only.
200 .000200 5.08 .000400 10 +.001000 / -.000000 25.4 / 0.0 * * * *

Hardness Specifications by Material

Material Hardness Material Hardness Material Hardness
420 Stainless **RC 52 Min. Chrome RC 60 - 67 2017 Alum RB 140 Min.
440 Stainless RC 58 - 65 T-15 RC 65 - 68 TiC Coated RC 58 Min.
430 Stailness **RC 20 Max. Rockbit RC 50 Min. (Higher per special requests) Silicon Nitride 1300 HV Min.
302/304 Stainless *RC 25 - 39 range Brass *RB 75 - 87 BG42 RC 60 - 65
316 Stainless *RC 25 - 39 range Carbon 1018 - 1065 RC 60 Min.    

*Reference Only.  Hardness may vary.  Please contact your local representative for hardness details.
**Limited availability and sizes.  Please contact your local representative for details.

Plastic Grade Specifications

Solid Plastic Ball Grades Size Range (Inches) Tolerance (Inches) Sphericity (Inches) Surface Finish
Grade 0* 2mm - 1" +/-0.0005" 0.0005" Polished
Grade I 2mm - 1 1/2" +/-.0010" 0.0005" Polished
Grade IIP 2mm - 2" +/-0.0020" 0.0010" Polished
Grade II 2mm - 2" +/-0.0020" 0.0010" As Ground
Grade III 2mm - 5" +/-0.0050" 0.0050" As Ground
*only available in certain materials

 

Please note that the material information provided on our website is for informational purposes only. The properties listed per product type are typical and can vary based on suppliers of raw materials and customer specific needs. Please contact customer service for verification prior to ordering. Price and delivery may be subject to change based on specific requirements.

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