U – Bolts and their specifications

U – Bolts are single piece cold or hot formed fasteners. They are manufactured from wire and round stock by cold or hot forming methods. There are 5 types of U bolts available in the market. They are explained as below.

Spring U bolt

These are the comprehensive range of spring U bolts that are well known for their quality and corrosive resistance. There are various sizes and design of bolts according to the industries.

U Bolts

These U Bolts are scientifically designed for all type of four wheelers. Available in thickness ranging from 10mm to 32mm thickness, these finds wide application in light four wheelers as well as heavy four wheelers. These bolts are manufactured using quality tested raw material.

Heavy duty U bolts

This category of U bolts is made of superior quality material and innovative technology. These are used in several industrial applications due to their high strength and durability. Furthermore, these can be attainable at most affordable costs.

Emergency U clamp bolts

These are made from high grade material with national and international standards. These bolts are used in different verticals of industries.

U clamps

These are manufactured from qualitative range of raw materials.

There is an international standard set by United States i.e. ASTM (American Society for Testing and Materials) specifications. Applicable ASTM specifications are:

A153 – Hot dip galvanizing specifications

A193 – Alloy steel and stainless steel bolting materials for high temperature service.

A194 – Carbon and alloy nuts for bolts for high pressure and high temperature service

A307 – carbon steel bolts and studs ranging from ¼” through 4” diameter.

A320 – alloy steel and stainless steel bolting materials for low temperature service.

A325 – structural bolts, steel, heat treated, 120/105 ksi minimum tensile strength.

A354 – quenched and tempered alloy bolts, studs, and other externally threaded fasteners.

A449 – Quenched and tampered steel bolts and studs.

A490 – structural bolts,, alloy steel, heat treated, 150 ksi tensile strength.

A563 – standard specification for carbon and alloy steel nuts.

F1554 – anchor bolts designed to anchor structural supports to concrete foundation

F2329 – new specification covering hot dip galvanizing


This is how U – Bolts are manufactured according to international standards and are used across the globe. Now, it’s time for you to decide which U bolt exactly matches your vehicle.

References: https://www.engineersedge.com/hardware/ubolt_application_and_design_9899.htm

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