, a Japanese Industrial Standard that serves as the gold standard for gear accuracy. If you’ve ever wondered why some machines purr with efficiency while others grind with noise, the answer usually lies within the tolerances defined in this document. What is JIS B 1702-1? At its core, JIS B 1702-1
is a classification system for the "flank tolerances" of cylindrical involute gears. While that sounds technical, it essentially defines how close a manufactured gear tooth must be to its mathematically perfect "ideal" shape to ensure smooth operation. The standard is identical to the international ISO 1328-1
standard, ensuring that gears made to these Japanese specifications are compatible with global engineering projects. The Blueprint of Accuracy JIS B 1702-1 categorizes gears into , typically ranging from Grade 0 (highest precision) Grade 12 (lowest precision)
. It measures three critical deviations that can make or break a machine's performance: Single Pitch Deviation ( f sub p t end-sub
The difference between the actual and theoretical spacing between adjacent teeth. Total Profile Deviation ( cap F sub alpha
How much the actual tooth curve deviates from the ideal involute curve. Total Helix Deviation ( cap F sub beta
The alignment of the tooth across the width of the gear; if this is off, the gear won't mesh evenly. Why Does It Matter?
Without these standards, mass production would be impossible.
JIS B 1702-1:1998 Cylindrical gears -- ISO system of accuracy
Understanding Jis B 1702-1 Pdf: A Comprehensive Guide
Introduction
JIS B 1702-1 is a Japanese Industrial Standard (JIS) that outlines the specifications for spur and helical gears. The standard is divided into multiple parts, with Part 1 covering the basic requirements for spur and helical gears. In this blog post, we will provide an overview of JIS B 1702-1 and explore the contents of the standard.
What is Jis B 1702-1?
JIS B 1702-1 is a standard published by the Japanese Standards Association (JSA) that defines the requirements for spur and helical gears used in various applications, including industrial machinery, automotive, and aerospace. The standard covers the design, manufacturing, and inspection of gears to ensure their quality and performance.
Contents of Jis B 1702-1 Pdf
The JIS B 1702-1 standard covers the following topics:
Importance of Jis B 1702-1
JIS B 1702-1 is an important standard for gear manufacturers, as it provides a set of guidelines for designing and manufacturing high-quality gears. By following the standard, manufacturers can ensure that their gears meet the required performance and safety standards. jis b 1702-1 pdf
Applications of Jis B 1702-1
JIS B 1702-1 is widely used in various industries, including:
Conclusion
JIS B 1702-1 is a comprehensive standard that outlines the requirements for spur and helical gears. By understanding the contents of the standard, gear manufacturers can ensure that their products meet the required performance and safety standards. The standard is widely used in various industries, including industrial machinery, automotive, and aerospace.
Download Jis B 1702-1 Pdf
If you are interested in downloading the JIS B 1702-1 standard, you can visit the Japanese Standards Association (JSA) website or other online platforms that provide access to standards. However, please note that the standard is copyrighted, and you may need to purchase a copy or obtain permission to use it.
Additional Resources
JIS B 1702-1 standard, titled "Cylindrical gears — ISO system of flank tolerance classification — Part 1: Definitions and allowable values of deviations relevant to corresponding flanks of gear teeth,"
is the Japanese Industrial Standard for gear precision, based directly on ISO 1328-1 Overview of JIS B 1702-1
This standard establishes a classification system for the accuracy of cylindrical involute gears. It replaced the older 1976 version of JIS B 1702, shifting from a "grade" system (0–9) to a "tolerance class" system (equivalent to ISO 0–12) to align Japanese manufacturing with international benchmarks. Key Technical Aspects Accuracy Classes : It defines 13 tolerance classes, where represents the highest precision (master gears) and represents the lowest. Measurement Parameters
: The standard focuses on individual tooth deviations, including: Profile Deviation ( cap F sub alpha
The difference between the actual and theoretical tooth profile. Helix Deviation ( cap F sub beta
The accuracy of the tooth along its width (axial direction). Pitch Deviation ( cap F sub p
The spacing accuracy between adjacent teeth and the cumulative spacing over the entire gear.
: It applies to gears with pitch diameters up to 10,000 mm and modules ranging from 0.5 to 70. Practical Application
Engineers use JIS B 1702-1 to specify the required precision for gears based on their end-use. For example: High-speed turbines typically require Class 4 or 5. General industrial machinery often utilizes Class 8 or 9. Automotive transmissions
usually demand Class 6 or 7 for noise reduction and durability. Accessing the PDF Because JIS standards are copyrighted by the Japanese Standards Association (JSA) , a Japanese Industrial Standard that serves as
, official PDF copies are generally not available for free. You can obtain the document through: JSA Web Store
: The primary source for the official Japanese and English translated versions. ANSI Webstore / IHS Markit
: International resellers that provide digital access to industrial standards. comparison table
between the old JIS grades and the current ISO-aligned classes?
Understanding JIS B 1702-1: A Guide to Gear Accuracy Standards (PDF & Basics)
When designing or sourcing gears, understanding accuracy standards is crucial for performance, noise reduction, and longevity. The JIS B 1702-1
standard is the go-to reference for gear engineers, particularly in Asian manufacturing.
This post breaks down what JIS B 1702-1 covers, the difference between old and new standards, and where to find the technical specifications. What is JIS B 1702-1? JIS B 1702-1
(Cylindrical gears—ISO system of flank tolerance classification) is a Japanese Industrial Standard that defines the accuracy grades for the tooth flanks of individual cylindrical involute gears. It sets the allowable deviations (tolerances) for: Pitch Errors: Single pitch, cumulative pitch. Tooth Profile Error: How closely the gear teeth match the ideal involute curve. Helix Error (Lead Error): The accuracy of the tooth alignment across the face width. Key Takeaways: JIS B 1702-1:2016 vs. 1998
The standard has evolved to align with international ISO standards. JIS B 1702-1:2016 (Current):
Replaces the 1998 version, focusing on flank tolerance classification. JIS B 1702-1:1998 (Historical):
Often referred to in older designs, covering 13 grades of accuracy (0–12). "N" Grade:
If you see "N" before a grade (e.g., N7), it indicates it follows the newer JIS B 1702 standards rather than the obsolete 1976 standard. Gear Accuracy Grades (N0–N12)
JIS B 1702-1 defines 13 grades (grouped from 0, the highest precision, to 12, the lowest). Application Grade Type of Gear
High-precision, high-speed (Robotics, Aircraft, Machine tools)
General precision (Automotive transmissions, High-load industrial) General purpose (General industrial machinery) N9 – N12 Lower precision (Conveyors, Slow agricultural machinery) Where to Access the JIS B 1702-1 PDF
As a technical standard, the full text of JIS B 1702-1 is protected by copyright. You can purchase the official documentation from the following sources: JSA (Japanese Standards Association) Webdesk The primary source for English editions. TechStandardsStore Authorized provider of JIS PDFs. Standards Supply Another reputable source for purchasing the document. Key Technical Aspects for Designers Module Range: Scope : The standard applies to spur and
The standards are typically applied to gears with a normal module (
) from 0.1mm to 2.0mm in some specialized standards, or much larger in general industrial applications. Measuring Techniques: It is recommended to use the procedures outlined in ISO/TR 10064-1 to evaluate the deviations defined in JIS B 1702-1. Pairing with JIS B 1702-2: While Part 1 focuses on individual tooth flank accuracy, JIS B 1702-2
covers radial composite deviations (how the gear performs when meshed).
Disclaimer: Standards documents are updated periodically. Always check the Japanese Standards Association website for the most recent revision. Accuracy of Gears | KHK
Understanding JIS B 1702-1: The Standard for Gear Accuracy The JIS B 1702-1 standard is the primary Japanese Industrial Standard for classifying the accuracy of cylindrical involute gears. Established by the Japanese Standards Association (JSA), it provides the technical definitions and allowable deviation values for tooth flanks, ensuring precision in mechanical systems ranging from heavy industrial machinery to high-precision robotics. Overview of JIS B 1702-1:2016
The current version of this standard is JIS B 1702-1:2016, which officially replaced the older 1998 and 1976 editions. It is largely harmonized with the international standard ISO 1328-1:1995, allowing Japanese manufacturers to maintain global compatibility. Scope and Application
This part of the JIS B 1702 series specifically covers the "ISO system of flank tolerance classification". It applies to individual cylindrical gears rather than gear pairs. The standard defines:
Accuracy Grades: It describes 13 grades of gear accuracy, ranging from Grade 0 (the highest precision) to Grade 12 (the lowest).
Measurement Parameters: Accuracy is determined by evaluating specific deviations, including: Single Pitch Deviation ( fptf sub p t end-sub
): The difference between the actual measured pitch and the theoretical circular pitch.
Total Profile Deviation: Measures how closely the actual tooth profile matches the ideal involute curve.
Total Helix Deviation: Evaluation of the tooth trace or lead error. Technical Constraints
The tolerances outlined in JIS B 1702-1 apply to gears within specific geometric ranges: Reference Diameter ( ): 5 mm to 15,000 mm. Normal Module ( ): 0.5 mm to 70 mm. Number of Teeth ( ): 5 to 1,000. Helix Angle ( ): Up to 45°. Comparison with Related Standards
The JIS B 1702 series is divided into multiple parts to address different measurement methods and materials: Accuracy of Gears | KHK
Found in the PDF's section on "Pitch deviations." If your gear has high Fp, it will vibrate. The JIS table provides exact micrometers (µm) of error allowed based on pitch diameter and grade.
A genuine copy of the standard includes these essential sections:
Once you acquire the official PDF, do not read it cover to cover. Skip to these critical tables:
If you need the PDF for professional use:
JIS B 1702-1 is a Japanese Industrial Standard specifying terminology, classifications, and requirements for protective gloves for industrial use — part 1 covers general definitions and basic requirements that apply across glove types used in industry.