PRODUCTS<\/a> | SCREWS<\/a><\/p>\n<\/div> Double-diameter screws are fastening components designed with two sections of different diameters along the same axis. This configuration makes it possible to integrate functions into a single component that would otherwise require additional machining operations or the use of several separate elements.<\/p>\n Unlike standard fasteners, double-diameter screws are frequently developed according to the needs of the application, combining coupling, centring, guiding or tightening areas within the same component.<\/p>\n For this reason, they are used in industrial machinery, mechanical assemblies, transmission systems, energy plants and equipment where dimensional accuracy and connection reliability are essential requirements.<\/p>\n<\/div><\/div><\/div> The distinctive feature of these screws is the presence of two different diameters on the same component.<\/p>\n The dimensional variation may involve the shank, the threaded sections or specific functional surfaces designed to perform different tasks within the assembly.<\/p>\n This solution makes it possible to:<\/p>\n Dimensional tolerances often play a decisive role, especially when the component contributes to the correct alignment of moving parts.<\/p>\n<\/div><\/div><\/div><\/div><\/div> We supply custom-designed fasteners for critical applications \u2014 with certified quality, full traceability, and technical support. Double-diameter screws are used in applications where a standard screw cannot meet all the required functional requirements at the same time.<\/p>\n The main sectors of use include:<\/p>\n In many cases, the component performs fastening, centring and positioning functions at the same time, contributing to the overall precision of the assembly.<\/p>\n<\/div><\/div><\/div> Double-diameter screws can be manufactured with different configurations according to the project specifications.<\/p>\n The most common solutions include:<\/p>\n The final configuration depends on the functions that the fastener must perform within the mechanical system.<\/p>\n<\/div><\/div><\/div> Double-diameter screws generally do not correspond to a single specific dimensional standard.<\/p>\n Whenever possible, head geometries, threads and dimensional characteristics are developed by taking ISO, DIN or UNI standards relating to the individual parts of the component as references.<\/p>\n Design therefore requires a specific assessment of the functional dimensions, tolerances and expected operating conditions.<\/p>\n<\/div><\/div><\/div> Material selection depends on the level of mechanical stress and the operating environment.<\/p>\n The most commonly used materials include:<\/p>\n For applications subject to high loads, quenched and tempered alloy steels are frequently used.<\/p>\n<\/div><\/div><\/div> Surface treatments are selected according to environmental conditions and the required durability of the component.<\/p>\n The most commonly used include:<\/p>\n The correct choice of treatment contributes to corrosion protection and tightening stability over time.<\/p>\n<\/div><\/div><\/div> Double-diameter screws are among the components frequently developed for specific technical applications.<\/p>\n EFS supports supplies intended for highly complex industrial sectors, coordinating production through qualified Italian and European suppliers and managing the entire process, from material selection through to final inspections.<\/p>\n Supplies may include:<\/p>\n They are used when the fastener must perform tightening, centring or positioning functions at the same time, which cannot be achieved with a standard screw.<\/p>\n<\/div> There is no specific standard defining all possible configurations. The geometries are generally developed according to the requirements of the application.<\/p>\n<\/div> Yes. In many applications, combinations of different diameters, pitches or threads are used to meet specific functional requirements.<\/p>\n<\/div> Machinery, Oil & Gas, energy, heavy-duty automotive, railway, industrial plant engineering and transmission systems are among the main sectors that use this type of fastener.<\/p>\n<\/div><\/div><\/div><\/div><\/div> We supply custom-designed fasteners for critical applications \u2014 with certified quality, full traceability, and technical support.Double Diameter Screws<\/h1><\/div><\/div><\/div>
![](\"https:\/\/www.efsfasteners.com\/wp-content\/uploads\/2026\/06\/efs-vite-doppio-diametro_3.jpg\" "\\"efs-vite-doppio-diametro_3\\"")
<\/span><\/div><\/div><\/div><\/div><\/div>Characteristics of Double-Diameter Screws<\/h2><\/div>
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NEED A PARTNER FOR SPECIAL BOLTS?<\/h3><\/div>
Fill out the contact form or call us: our team is ready to assist you with tailored solutions.<\/p>\n<\/div><\/div><\/div>Industrial Applications of Double-Diameter Screws<\/h2><\/div>
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Available Geometries and Configurations<\/h2><\/div>
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ISO, DIN and UNI Standards<\/h2><\/div>
Available Materials<\/h3><\/div>
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Surface Treatments<\/h3><\/div>
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EFS Capabilities<\/h2><\/div>
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FAQ<\/h2><\/div>
When Are Double-Diameter Screws Used?<\/h3><\/div>
Are Double-Diameter Screws Standardized?<\/h3><\/div>
Is It Possible to Manufacture Double-Diameter Screws with Different Threads?<\/h3><\/div>
Which Sectors Use Double-Diameter Screws the Most?<\/h3><\/div>
NEED A PARTNER FOR SPECIAL BOLTS?<\/h3><\/div>
Fill out the contact form or call us: our team is ready to assist you with tailored solutions.<\/p>\n<\/div><\/div><\/div>PRODUCTS APPLIED TO INDUSTRY<\/h3><\/div><\/div><\/div>
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Hexagonal Nut for Oil&Gas Industry<\/a><\/h4>
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