Whether you are a manufacturing engineer, a quality control specialist, or a product designer, understanding how to interpret and apply this standard is essential for global compliance and high-performance gear design. What is JIS B 1702-1?

The difference between the actual pitch and the theoretical pitch. Total Cumulative Pitch Deviation ( cap F sub p The maximum deviation across all teeth in the gear. Total Profile Deviation ( cap F sub alpha The total error in the shape of the tooth profile. Total Helix Deviation ( cap F sub beta

| Aspect | Old Standard (JIS B 1702:1976) | New Standard (JIS B 1702-1:1998/2016) | | :--- | :--- | :--- | | | Single standard covering most errors | Split into Part 1 (flank errors) and Part 2 (radial errors) | | Precision Grades | 9 grades (0 to 8) | 13 grades (0 to 12) | | Base International Standard | Japan's own | ISO 1328-1 (equivalent) | | Notation | Referred to simply as "Grade 4" | Designated with an "N" prefix to avoid confusion (e.g., "N8") |

Understanding JIS B 1702-1: The Standard for Spur and Helical Gear Accuracy

Modern gear design often distinguishes between the "Old JIS" (B 1702:1976) and the "New JIS" (B 1702:1998/2016).

The is a cornerstone for mechanical engineers, gear designers, and quality control professionals working within the Japanese manufacturing sector and companies adhering to Japanese Industrial Standards (JIS). This document outlines the standards for cylindrical gear tooth accuracy, providing a structured system for classifying tolerances.

The modern JIS B 1702 series splits gear evaluation metrics across three distinct focus areas: Jis B 1702-2 | PDF - Scribd

This article dives deep into everything you need to know about JIS B 1702-1, the implications of using a digital copy, and how to leverage this standard for flawless gear manufacturing.

This is the shape accuracy of the involute curve. The PDF includes complex formulas involving base circle radius. Do not try to memorize this; use the lookup tables.

The highest precision, typically used for aerospace or high-end metrology.

JIS B 1702-1 is largely harmonized with international standards to allow for global manufacturing compatibility.

): The deviation of the entire tooth flank profile from the design shape. The accuracy of the helix angle for helical gears. Runout Error ( Frcap F sub r

Suitable for general machinery where moderate tolerances are acceptable. 4. Methodologies for Evaluation

is the Japanese Industrial Standard for gear precision, based directly on ISO 1328-1 Overview of JIS B 1702-1