ISO 6336-1-2019 PDF

Full title and description

Calculation of load capacity of spur and helical gears — Part 1: Basic principles, introduction and general influence factors. This part of ISO 6336 establishes the basic principles, definitions and general influence factors used throughout the ISO 6336 series for rating the load‑carrying capacity of cylindrical gears with straight or helical involute teeth.

Abstract

ISO 6336-1:2019 presents the basic principles, an introduction and general influence factors for calculating the load capacity of spur and helical gears. Together with the other parts of ISO 6336 it provides a uniform method to compare gear designs and to calculate resistance to failure modes such as pitting, tooth root breakage and tooth flank fracture, within the validated parameter ranges given in the standard. The part clarifies applicability limits and assumptions that users must observe.

General information

• Status: Published.
• Publication date: November 2019.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 21.200 (Gears and transmissions).
• Edition / version: Edition 3 (ISO 6336-1:2019).
• Number of pages: 134 pages.

Scope

Provides the basic principles, definitions, symbols and general influence factors used to calculate the load capacity of spur and helical involute cylindrical gears. The methods and formulae are intended for experienced gear designers to compare gear designs and to assess risk of failure modes such as pitting and tooth root breakage. The standard specifies validated parameter ranges (for example normal working pressure angles roughly 15°–25°, reference helix angles up to about 30° and transverse contact ratios within approximately 1.0 to 2.5) and lists conditions where the formulae are not applicable (e.g., transverse contact ratio < 1.0, interference, pointed teeth, zero backlash, certain finishing processes and vibratory conditions). Users are advised to verify results by experience outside the validated ranges.

Key topics and requirements

• Definitions, symbols and units for gear rating calculations.
• Basic principles and presentation of the rating philosophy used across the ISO 6336 series.
• Application factor (KA) — accounting for externally induced torque fluctuations and overloads.
• Mesh/load sharing factors (Kγ) for multiple-path transmissions and uneven load distribution.
• Dynamic/internal factor (Kv) — accounting for internal dynamic effects and vibration.
• Face load distribution factors (KHβ, KFβ) and transverse load distribution factors (KHα, KFα) — for contact and bending stress load distribution effects.
• Tooth stiffness parameters and their use in determining load distribution across the face width.
• Guidance on factor selection, limits of applicability and informative annexes with explanatory notes and example guidance.

Typical use and users

Intended for experienced gear designers, engineers and technical specialists involved in the design, rating and analysis of cylindrical spur and helical gear pairs and gearsets. Typical applications include power transmission design in industrial gearboxes, automotive and heavy machinery, where standardized calculation of pitting resistance and tooth root strength is required for design comparison, specification, and verification within the standard’s applicability ranges. Users often consult this part first to select and justify the influence factors used in Parts 2, 3 and other series parts.

Related standards

ISO 6336 is a multi‑part series; related parts include ISO 6336-2 (surface durability/pitting), ISO 6336-3 (tooth bending strength), ISO 6336-5 (strength and material quality), ISO 6336-6 (service life under variable load) and technical parts for scuffing and micropitting (e.g., Parts 20–22) as well as calculation examples (Parts 30–31). Part 1 is the foundational document referenced by these parts. National and industry standards for gear rating (for example DIN and relevant technical reports) are often used alongside ISO 6336.

Keywords

gear rating, load capacity, spur gear, helical gear, pitting, tooth root bending, application factor, dynamic factor, face load factor, transverse load factor, ISO 6336.

FAQ

Q: What is this standard?

A: ISO 6336-1:2019 is Part 1 of the ISO 6336 series that defines basic principles, terminology and general influence factors for calculating the load‑carrying capacity of spur and helical cylindrical gears.

Q: What does it cover?

A: It covers definitions, symbols, basic rating principles and general factors (application, dynamic, face and transverse load distribution, mesh load, stiffness parameters, etc.) used to determine contact and bending stresses and to select inputs for the procedural Parts 2, 3 and others that calculate pitting resistance and tooth bending strength. The part also states validated ranges and applicability limits.

Q: Who typically uses it?

A: Experienced gear designers, gearbox engineers, tribologists and standards/quality engineers who need a harmonized method to rate and compare cylindrical gear designs and to select appropriate influence factors for detailed strength and life calculations.

Q: Is it current or superseded?

A: ISO 6336-1:2019 is the current published edition (Edition 3) replacing earlier editions (for example the 2006 edition). The ISO record shows the 2019 edition as published and the series is subject to periodic review. Users should check for any amendments or later revisions when planning compliance or design work.

Q: Is it part of a series?

A: Yes — ISO 6336 is a multi‑part series addressing different calculation aspects: Part 1 (principles and influence factors), Part 2 (pitting), Part 3 (bending strength), Part 5 (materials), Part 6 (variable load life) and additional parts/technical reports for scuffing, micropitting and examples. Part 1 is the foundational document referenced by the other parts.

Q: What are the key keywords?

A: Gear rating, pitting, tooth root bending, application factor (KA), dynamic factor (Kv), face load factor (KHβ / KFβ), transverse load factor (KHα / KFα), mesh load factor (Kγ), tooth stiffness, spur gear, helical gear.