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Gear Terminology

Gear Nomenclature

Gear Symbols . Used in gear design and production, below gives you an outline of some that are used.

Gear Calculator
DescriptionSymbolUnits
Operating pitch diameterdwmm
Circumferential backlashjtmm
Normal backlashjnmm
Transverse pitch on ref. diameterptmm
Dedendumhfmm
Addendumhamm
Tooth depthhmm
Tip diameterdamm
Root diameterdfmm
Transverse tooth thickness on ref. dia.stmm
Reference diameterdmm
DescriptionSymbolUnits
Normal pitch on ref. cylinderPnmm
Addendum of gear ref. profilehaPmm
Dedendum of gear ref. profilehfPmm
DescriptionSymbolUnits
Active root diameterdNfmm
Root form diameterdFfmm
Normal pitch on ref. cylinderPnmm
Normal tooth thickness on ref. dia.snmm
DescriptionSymbolUnits
Working transverse pressure angleawt° degrees
Base diameterdbmm
Reference diameterdmm
Operating pitch diameterdwmm
DescriptionSymbolUnits
Axial pitch on the reference cylinderPxmm
Helix angle at reference diameterß° degrees
Technical FilesGear ShopGear Metrology

Gear Standards & Quality Grades

A comparision on quality grades in some of the used gear standards.

Gear Calculator
Gear Grinding Quality Comparisons
Standards
Quality Grades
DIN 3961 - 3962345
ISO 1328 : 1995/97345
ISO 1328 : 2013A3A4A5
AGMA 2000Q14Q13Q12
AGMA 2015A3A4A5
Gear Cutting Quality Comparisons
Standards
Quality Grades
DIN 3961 - 3962678
ISO 1328 : 1995/97678
ISO 1328 : 2013A6A7A8
AGMA 2000Q11Q10Q9
AGMA 2015A6A7A8
Standards
GeometryDIN 3960
ISO 21771
DIN 58405
Reference ProfileDIN 867
ISO 53
DIN 3972
DIN 58412
DIN 58400
Backlash and
tooth thickness
DIN 3967
DIN 58405
ISO TR 10064-2
QualityDIN 3961 - 3962
ISO 1328 : 1995/97
ISO 1328 : 2013
AGMA 2000
AGMA 2015
Gear blanks and
centre distance
tolerance
DIN 3964
ISO 10064-3
RatingDIN3990
ISO 6336