Everything you need to know about bolts: DIN933 vs. DIN931

Bolts are an important part of every industry, from construction to manufacturing. Among the many bolt options, DIN933 and DIN931 are two commonly used types. In this blog, we’ll explore the differences between these bolts, their applications, and which one is best for a specific project.

DIN933 Bolts: Basic Overview

DIN933 bolts, also known as fully threaded bolts, are characterized by uniform threads along the entire length of the bolt. This thread ensures a secure connection and makes DIN933 bolts suitable for applications requiring high strength resistance. These bolts are often used to tightly fasten two components together, making them a popular choice in heavy machinery and construction projects.

DIN931 Bolts: half threaded but equally effective

DIN931 bolts, on the other hand, have a partially threaded shaft with a smooth section just below the head. While this threaded portion allows for secure fastening, the smooth portion provides greater load-bearing capacity. DIN931 bolts are typically used in applications where shear strength is critical, such as connecting rotating parts or structural elements. They are designed to have a stronger grip and are ideal for use on machinery that is subject to significant pressure or severe vibration.

Applications and best uses

Depending on the requirements of the project, selecting the correct bolt is critical to ensuring its reliability and longevity. DIN933 bolts are fully threaded and are best suited for fastening parts together tightly and securely. These bolts excel in applications requiring high resistance to loosening or pulling forces, making them the first choice for heavy construction, bridges and automotive manufacturing.

Alternatively, DIN931 bolts with a semi-threaded design are more suitable for different purposes. Their shear strength capabilities make them ideal for use in machinery subject to high rotational or transverse stresses, such as gears, turbine components and other rotating parts in industrial equipment. The smooth portion of the shaft provides extra strength, ensuring these bolts can withstand extreme conditions and prevent premature failure.


In a world where precision and reliability are paramount, choosing the right bolt is crucial. DIN933 bolts are fully threaded and offer excellent resistance, making them ideal for applications where safe fastening is critical. DIN931 bolts, on the other hand, have a semi-threaded design that excels in shear strength applications, ensuring reliability in machinery subjected to strong rotational forces.

Understanding the differences between DIN933 and DIN931 bolts enables you to choose the most appropriate option for your project, optimizing performance and ensuring safe operation. Consider the specific requirements of your application and make an informed decision on your bolting solution.

Post time: Oct-12-2023