{"id":5554,"date":"2025-12-19T08:13:58","date_gmt":"2025-12-19T08:13:58","guid":{"rendered":"https:\/\/korea-transmission.com\/?p=5554"},"modified":"2025-12-19T08:14:35","modified_gmt":"2025-12-19T08:14:35","slug":"technical-standards-for-set-screws-according-to-gb-t-3098-3-2016","status":"publish","type":"post","link":"https:\/\/korea-transmission.com\/id\/blog\/technical-standards-for-set-screws-according-to-gb-t-3098-3-2016\/","title":{"rendered":"Technical Standards for Set Screws According to GB\/T 3098.3-2016"},"content":{"rendered":"<div style=\"font-family: Arial, sans-serif; line-height: 1.6; max-width: 1200px; margin: 0 auto; padding: 20px; background-color: #f9f9f9; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.1);\">\n<h2>Introduction<\/h2>\n<p>As a seasoned mechanical materials expert, I have extensively worked with national and international standards for fasteners, including those governing set screws. GB\/T 3098.3-2016 is a critical Chinese national standard that specifies the mechanical properties of set screws, ensuring their reliability in various industrial applications such as machinery assembly, automotive components, and precision engineering. This standard aligns with global practices, drawing parallels to ISO 898-5, and focuses on hardness grades, material compositions, and performance criteria to prevent failures under load.<\/p>\n<p>In this article, I optimize and expand upon the core elements of the standard, incorporating detailed explanations of chemical compositions and mechanical properties based on verified data. This ensures compliance with industry best practices, emphasizing aspects like heat treatment, decarburization limits, and hardness testing methods.<\/p>\n<h2>Table of Contents<\/h2>\n<ul style=\"list-style-type: disc; padding-left: 20px;\">\n<li><a style=\"color: #007bff; text-decoration: none;\" href=\"#chemical-composition\">Chemical Composition of Set Screw Materials<\/a><\/li>\n<li><a style=\"color: #007bff; text-decoration: none;\" href=\"#mechanical-properties\">Mechanical Properties of Set Screws<\/a><\/li>\n<li><a style=\"color: #007bff; text-decoration: none;\" href=\"#faq\">Pertanyaan yang Sering Diajukan (FAQ)<\/a><\/li>\n<\/ul>\n<div id=\"chemical-composition\">\n<h2>Chemical Composition of Set Screw Materials<\/h2>\n<p>Set screws must meet specific chemical composition requirements to achieve the desired hardness and mechanical strength. The standard categorizes materials by hardness grades (14H, 22H, 33H, and 45H), specifying limits for carbon (C), phosphorus (P), and sulfur (S) content. Heat treatment processes like quenching and tempering are mandated for higher grades to enhance durability. Note that surface hardening is not permitted, and in case of disputes, finished product analysis is required.<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 20px 0; box-shadow: 0 1px 3px rgba(0,0,0,0.2);\">\n<thead>\n<tr style=\"background-color: #007bff; color: white;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\" colspan=\"2\">Hardness Grade<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Vickers Hardness HV min<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Bahan<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Heat Treatment\u00b9<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">C%, max\u00b2<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">C%, min\u00b2<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">P%, max\u00b2<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">S%, max\u00b2<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\" colspan=\"2\">14H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">140<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Carbon steel\u00b3<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">\/<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">\/<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.11<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.15<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\" colspan=\"2\">22H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">220<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Carbon steel\u2074<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Quenched and tempered<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.19<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\" colspan=\"2\">33H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">330<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Carbon steel\u2074<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Quenched and tempered<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.19<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\" rowspan=\"3\">45H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">450<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Carbon steel\u2074,\u2075<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Quenched and tempered<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.45<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">450<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Carbon steel with added elements\u2074 (boron, manganese, or chromium)<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Quenched and tempered<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.28<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">450<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Alloy steel\u2074,\u2076<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Quenched and tempered<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.5<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.3<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.05<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"font-size: 14px; color: #666;\"><strong>Catatan:<\/strong><br \/>\n\u00b9 Surface hardening is not permitted.<br \/>\n\u00b2 In case of dispute, perform finished product analysis.<br \/>\n\u00b3 Free-cutting steel may be used with max Pb 0.35%, P 0.11%, S 0.34%.<br \/>\n\u2074 Steel with max Pb content of 0.35% may be used.<br \/>\n\u2075 Applicable only for d \u2264 M16.<br \/>\n\u2076 Alloy steels must contain at least one of: Cr 0.30%, Ni 0.30%, Mo 0.20%, V 0.10%. For multiple elements, total content should be at least 70% of the sum of individual minima.<\/p>\n<p>In practice, these compositions ensure set screws resist shear and maintain integrity in high-vibration environments. For instance, higher carbon content in 45H grades improves hardenability but requires precise control to avoid brittleness.<\/p>\n<\/div>\n<div id=\"mechanical-properties\">\n<h2>Mechanical Properties of Set Screws<\/h2>\n<p>The mechanical properties outlined in GB\/T 3098.3-2016 include hardness ranges measured via Vickers (HV), Brinell (HBW), and Rockwell (HRB\/HRC) methods, along with decarburization and surface hardness limits. These ensure set screws perform under axial loads without deformation or failure. Testing is conducted on finished products to verify compliance.<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 20px 0; box-shadow: 0 1px 3px rgba(0,0,0,0.2);\">\n<thead>\n<tr style=\"background-color: #007bff; color: white;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Hardness Grade<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Vickers Hardness HV10 max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Brinell Hardness HBW F=30D\u00b2 min<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Brinell Hardness HBW F=30D\u00b2 max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Rockwell Hardness HRB min<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Rockwell Hardness HRB max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Rockwell Hardness HRC min<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Rockwell Hardness HRC max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Thread Non-Decarburized Layer Height E\/mm min<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Thread Full Decarburization Layer Height G\/mm max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">Surface Hardness HV0.3 max<\/th>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">No Carburization HV0.3 max<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">14H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">290<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">133<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">276<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">75<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">105<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">22H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">300<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">209<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">285<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">95<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">A<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">A<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">30<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">1\/2 H\u2081<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.015<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">320<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">c<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">33H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">440<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">314<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">418<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">33<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">44<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">2\/3 H\u2081<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">0.015<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">450<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">c<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">45H<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">560<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">428<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">532<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">–<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">45<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">53<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">3\/4 H\u2081<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">B<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">580<\/td>\n<td style=\"padding: 10px; border: 1px solid #ddd; text-align: center;\">c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"font-size: 14px; color: #666;\"><strong>Catatan:<\/strong><br \/>\na. For 22H grade, use HRB min and HRC max if Rockwell testing is performed.<br \/>\nb. No full decarburization layer is allowed for 45H.<br \/>\nc. When measured with HV0.3, surface hardness should not exceed core hardness by more than 30 HV units.<\/p>\n<p>These properties are essential for applications requiring high torque resistance. For example, in 45H set screws, the stringent decarburization controls prevent thread weakening, which is crucial in heavy machinery.<\/p>\n<\/div>\n<div id=\"faq\">\n<h2>Pertanyaan yang Sering Diajukan (FAQ)<\/h2>\n<dl style=\"margin: 20px 0;\">\n<dt style=\"font-weight: bold; margin-top: 10px;\">1. What is the primary difference between hardness grades in GB\/T 3098.3-2016?<\/dt>\n<dd>The grades (14H to 45H) escalate in minimum hardness and heat treatment requirements, with higher grades like 45H using alloy steels for superior strength in demanding applications, while lower grades like 14H suffice for general use.<\/dd>\n<dt style=\"font-weight: bold; margin-top: 10px;\">2. Why is surface hardening prohibited in this standard?<\/dt>\n<dd>Surface hardening can lead to uneven stress distribution and potential cracking under load. The standard mandates uniform quenching and tempering to ensure consistent mechanical properties throughout the set screw.<\/dd>\n<dt style=\"font-weight: bold; margin-top: 10px;\">3. How does decarburization affect set screw performance?<\/dt>\n<dd>Decarburization reduces carbon content on the surface, weakening threads and increasing failure risk. The standard limits this (e.g., max 0.015 mm for 22H and 33H) to maintain thread integrity.<\/dd>\n<dt style=\"font-weight: bold; margin-top: 10px;\">4. Can free-cutting steels be used for all hardness grades?<\/dt>\n<dd>Free-cutting steels are permitted for 14H with specified impurity limits, but for higher grades, controlled carbon and alloy steels are required to achieve the necessary hardenability without compromising machinability.<\/dd>\n<dt style=\"font-weight: bold; margin-top: 10px;\">5. What testing methods are recommended for verifying compliance?<\/dt>\n<dd>Vickers (HV10 or HV0.3), Brinell (HBW with F=30D\u00b2), and Rockwell (HRB\/HRC) hardness tests are specified. In disputes, finished product chemical analysis and metallographic examination for decarburization are essential.<\/dd>\n<dt style=\"font-weight: bold; margin-top: 10px;\">6. How does GB\/T 3098.3-2016 compare to ISO 898-5?<\/dt>\n<dd>Both standards are similar in hardness classifications and material requirements, but GB\/T 3098.3-2016 includes specific allowances for Chinese steel grades and emphasizes finished product testing for quality assurance.<\/dd>\n<\/dl>\n<\/div>\n<h2>Conclusion<\/h2>\n<p>Adhering to GB\/T 3098.3-2016 ensures set screws meet rigorous mechanical and material standards, enhancing safety and performance in engineering applications. For custom consultations or sourcing compliant fasteners, contact a certified supplier.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Introduction As a seasoned mechanical materials expert, I have extensively worked with national and international standards for fasteners, including those governing set screws. GB\/T 3098.3-2016 is a critical Chinese national standard that specifies the mechanical properties of set screws, ensuring their reliability in various industrial applications such as machinery assembly, automotive components, and precision engineering. [&hellip;]<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[220],"tags":[],"class_list":["post-5554","post","type-post","status-publish","format-standard","hentry","category-technical-documentation-and-references"],"_links":{"self":[{"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/posts\/5554","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/comments?post=5554"}],"version-history":[{"count":2,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/posts\/5554\/revisions"}],"predecessor-version":[{"id":5556,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/posts\/5554\/revisions\/5556"}],"wp:attachment":[{"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/media?parent=5554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/categories?post=5554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/korea-transmission.com\/id\/wp-json\/wp\/v2\/tags?post=5554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}