ISO 1328-1:2013 pdf download.Cylindrical gears一ISO system of  flank tolerance classification -Part 1:Definitions and allowable values of deviations relevant to flanks of gear teeth.
This part of ISO 1328 establishes a tolerance classification system relevant to manufacturing and conformity assessment of tooth flanks of individual cylindrical involute gears. It specifies definitions for gear flank tolerance terms, the structure of the flank tolerance class system, and allowable values.
This part of ISO 1328 provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances. Eleven flank tolerance classes are defined, numbered ito 11, in order of increasing tolerance. Formulae for tolerances are provided in 5.3. These tolerances are applicable to the following ranges:
Gear design is beyond the scope of this part of ISO 1328.
Surface texture is not considered in this part of ISO 1328. For additional information on surface texture, see ISO/TR 10 064-4.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable to its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 701, international gear notation — Symboisfor geometrical data
ISO 1122-1, Vocabulary of gear terms — Part 1: Definitions related to geometry
ISO 1328-2, Cylindrical gears — ISO system of accuracy — Part 2: Definitions and allowable values of deviations relevant to radial composite deviations and runout information
ISO/TR 10 064-1, Code of inspection practice — Part 1: Inspection of corresponding flanks of gear teeth ISO/TS 16610-1, Geometrical product specifications (GPS) — Filtration — Part 1: Overviewand basic concepts
ISO 16610-21, Geometrical product specifications (GPS) — Filtration — Part 21: Linear profile filters:
Gaussian filters
ISO 21771, Gears — Cylindrical involute gears and gear pairs — Concepts and geometry
3 Terms, definitions and symbols
3.1 Fundamental terms and symbols
For the purposes of this part of ISO 1328, the following terms, definitions and symbols apply.
NOTE 1 For other definitions of geometric terms related to gearing, see ISO 701, ISO 1122-1 and ISO 21771. NOTE 2 Some of the symbols and terminology contained in this part of ISO 1328 might differ from those used in other documents and International Standards.
NOTE 3 The terminology and symbols used in this part of ISO 1328 are listed, in alphabetical order, by term in Table 1. and in alphabetical order, by symbol in Table 2. The text of terms used in Table 1 has been adjusted to form groups of logical terms. Subscript “T” is used for tolerance values.
3.2 General dimensions
3.2.1
reference diameter
d
diameter of reference circle
Note 1 to entry: The reference diameter is used to calculate values of tolerances.
Note 2 to entry: See ISO 21771:2007, 4.2.4. ISO 1328-1 pdf download.