Normal modulemnmm
Normal pressure angleαn°
Helix angleβ°
Number of teethz
Profile shift coefficientx
Normal tooth allowance DIN 3967
Diameter of measurement ball (input)DMmm
Spanned teeth for measurement (input)k

The method and sign convention is as by ISO 21771 using a none topping DIN 867 1.25 / 0.20 / 1.00 reference profile.

Calculation is valid for a value of 1 normal module and above. Reference diameter 10mm and upto and including 10000mm.

A negative sign is used for the number of teeth of an internal gear but all diameters are always positive.

Helix angle is always entered as a positive value. Results are the same for left and right helix.

If diameter of measurement ball (input) and spanned teeth for measurement (input) are left blank, default values are calculated.

Distance over two pins per DIN 3960.

This calculation is provided free of charge by Ondrives Ltd. The software is tested and no errors are known, but there is no warranty for the correctness of the results and for availability of the calculation. The usage is at own risk.

Gear Reference ProfileDIN 867
Dedendum coefficienthfP1.2500
Root radius factorρfP0.2000
Addendum coefficienthaP1.0000
Tip alterationk*mn0.0000mm
Transverse modulemt 1.0000mm
Transverse pressure angleαt 20.0000°
Base helix angleβb 0.0000°
Base diameterdb 28.1908mm
Reference diameterd 30.0000mm
Tip diameterda 32.0000mm
Root diameterdf 27.3352 27.4176mm
Root form diameterdFf 28.3762 28.4047mm
Normal tooth allowanceAsn -0.0600 -0.0300mm
Normal tooth thickness at reference diametersn 1.5108 1.5408mm
Normal tooth thickness at tip diametersan 0.6734 0.7054mm
Generating profile shift coefficientxE -0.0824 -0.0412
Generating profile shift coefficient at undercut limitxEmin -0.6363
Measuring pin / ball diameterDM 1.7000mm
Radial single ball distanceMrK 16.0821 16.1190mm
Distance over two ballsMdK 32.1641 32.2380mm
Distance over two pinsMdR 32.1641 32.2380mm
Diameter of pin / ball contactdM 29.8612 29.9256mm
Number of teeth for span measurementk 3
Base tangent length (Span)Wk 7.7441 7.7723mm
Diameter of span contactdMWk 29.2351 29.2426mm

(No Warnings)


dMdMWkdbdFf