{"id":5517,"date":"2026-05-22T10:00:06","date_gmt":"2026-05-22T01:00:06","guid":{"rendered":"https:\/\/ohtavn.com\/?post_type=media&p=5517"},"modified":"2026-05-06T16:14:47","modified_gmt":"2026-05-06T07:14:47","slug":"what-is-a-hexagon-socket-head-bolt","status":"publish","type":"media","link":"https:\/\/ohtavn.com\/en\/media\/what-is-a-hexagon-socket-head-bolt\/","title":{"rendered":"What is a hexagon socket head bolt? Basic knowledge of standards, strength, and procurement in Vietnam"},"content":{"rendered":"
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Introduction<\/h3>\n<\/div>\n
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In manufacturing design, development sites, and procurement operations, the “Hexagon Socket Head Cap Screw” is one of the most frequently seen fastening parts. Also known as “Cap Bolts” or “Cap Screws,” these are not merely simple fasteners. Compared to conventional hex bolts, they allow for more space-saving designs and achieve extremely high tightening strength, making them indispensable in precision equipment fields such as machine tools, automotive parts, and automation lines.<\/p>\n<\/div>\n

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Especially in Vietnam’s manufacturing sites, stable procurement of bolts meeting quality standards similar to Japanese companies (JIS standards, etc.) directly impacts production line utilization rates and final product safety. This article briefly explains the basic definition, technical merits, strength class details, and efficient procurement methods in Vietnam for busy practitioners in 3 minutes. Together with the solutions provided by us, Ohta Vietnam, we hope this serves as an aid to your procurement strategy.<\/p>\n<\/div>\n

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Definition and Structure of Hexagon Socket Head Cap Screws (Cap Screws)<\/h3>\n<\/div>\n
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JIS B 1176 Standard and Basic Shape<\/h4>\n<\/div>\n
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Hexagon socket head cap screws are a general term for bolts with a hexagonal hole in a cylindrical head. In Japanese Industrial Standards (JIS), they are defined as “JIS B 1176”<\/strong> and conform to the international standard “ISO 4762”<\/strong>. The biggest feature is that they use a “Hexagon Key (Allen Key)” instead of a spanner or wrench for tightening.<\/p>\n<\/div>\n

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While general hex bolts (JIS B 1180) are turned by gripping the outside of the head, hexagon socket head cap screws transmit torque using the inside (hole) of the head. This eliminates the need to secure space around the bolt for turning tools, contributing significantly to the miniaturization and weight reduction of machinery.<\/p>\n<\/div>\n

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Space Saving and Safety via “Counterboring”<\/h4>\n<\/div>\n
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The greatest design advantage is the suitability for “counterboring” processing, where the head is embedded inside the part. The cylindrical head fits perfectly into the counterbored hole, keeping the part surface flat.<\/p>\n<\/div>\n

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This prevents the bolt head from protruding on moving machine parts, reducing labor accident risks such as workers’ clothing getting caught. It also makes the appearance smart, making it suitable for products requiring good design.<\/p>\n<\/div>\n

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Phenomenal Strength: The Power of Strength Class “12.9”<\/h3>\n<\/div>\n
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The Decisive Difference from General Hex Bolts<\/h4>\n<\/div>\n
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Another major reason why hexagon socket head cap screws are chosen lies in their overwhelming “strength.” While many iron hex bolts generally in circulation are strength class “4.8”, standard hexagon socket head cap screws are manufactured with the extremely high strength class of “12.9”<\/strong>.<\/p>\n<\/div>\n

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This number “12.9” represents the following mechanical properties:<\/p>\n<\/div>\n

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