Dew needle rollers Specifications Loose needle rollers Dimensions Outside diameter , mm (in) Overall length , mm (in) 1.5 to 25 mm 1.5 to 100 mm Materials Standard Alternative Sae 52100 bearing quality chrome steel Available on request Hardness Standard Alternative Hrc 60 to 64 Hrc 45 available on request Surface finish Standard , mm (in) Alternative Od ground and lapped to surface finish of 0.2 microns ra maximum Surface finish as low as 0.050 microns ra Available on request Tolerance Out side diameter , mm (in) Standard Alternatives Outside diameter , mm (in) Standard Alternatives +0.000-0.005 (+0.000-0.002) g5 +0.000-0.003 (+0.00000-0.000120) g3 +0.000-0.002 (+0.00000-0.0000.80) g2 +0.000-0.500 (+0.000 -0.020) +0.00-0.300 (+0.000- 0.012) +0.00-0.250 (+0.000 û 0.010) +0.00-0.100 (+0.000-0.004) Note : closer tolerance length rollers available Primarily in end ground configurations . Outside diameter , mm (in):1.5 to 25 mm Overall length , mm (in): 1.5 to 100 mm