When it comes to fasteners, particularly in engineering, construction, and automotive industries, two highly common referenced standards are DIN 933 and DIN 931. These standards specify two types of hex bolts & screws that can be used in various applications requiring high strength and reliability. Using our expert knowledge we will break down the key differences between DIN 933 and DIN 931 bolts, their applications, and why they’re crucial in different projects.
What are DIN Standards?
DIN (Deutsches Institut für Normung) standards are developed by the German Institute for Standardization and are widely recognized globally. They ensure that products, including bolts, meet specific requirements for quality, safety, and consistency. DIN 933 and DIN 931 are two such standards that pertain to hexagonal head bolts.
DIN 933 Bolts: Fully Threaded Hex Bolts
DIN 933 refers to hex bolts that are fully threaded along the length of the shank. This means the threading extends from just below the head all the way to the tip of the bolt. The key characteristics of DIN 933 bolts include:
- Full Threading: Provides maximum adjustability, making these bolts ideal for applications where the bolt needs to be adjusted or where materials of varying thicknesses need to be fastened together.
- Hexagonal Head: The six-sided head is designed for use with a wrench or socket, allowing for easy tightening and loosening.
- Materials: DIN 933 bolts are available in various materials, including stainless steel, carbon steel, and alloy steel, providing options for different levels of strength, corrosion resistance, and environmental conditions.
- Common Uses: These bolts are typically used in applications where a strong, fully threaded connection is necessary, such as in machinery, automotive components, and construction projects.
DIN 931 Bolts: Partially Threaded Hex Bolts
DIN 931 defines hex bolts that are partially threaded, meaning that only a portion of the shank is threaded while the rest is a smooth, unthreaded shaft. The key features of DIN 931 bolts include:
- Partial Threading: The unthreaded portion of the shank provides additional shear strength, making these bolts ideal for applications where alignment and load distribution are critical. The length of the threaded portion depends on the bolt’s length, with longer bolts having a longer unthreaded section.
- Hexagonal Head: Like DIN 933 bolts, these also feature a hex head for easy application with tools.
- Materials: Available in similar materials as DIN 933 bolts, including stainless steel, carbon steel, and alloy steel, catering to various strength and corrosion resistance needs.
- Common Uses: DIN 931 bolts are often used in situations where the bolt must pass through thick components and where a strong, non-threaded shank is needed to bear the shear forces, such as in structural applications, engine parts, and heavy machinery.
Comparing DIN 933 and DIN 931 Bolts
While both DIN 933 and DIN 931 bolts share similarities in terms of their hexagonal heads and material options, the key difference lies in the threading:
- DIN 933: Fully threaded, ideal for adjustable connections.
- DIN 931: Partially threaded, ideal for applications requiring strong shear resistance.
Choosing Between DIN 933 and DIN 931 Bolts
The choice between DIN 933 and DIN 931 bolts largely depends on the specific requirements of your project:
- If you need a bolt that can be easily adjusted and securely fastened through materials of varying thicknesses, DIN 933 bolts are your go-to option.
- If your application involves significant shear forces or requires precise alignment through thick components, DIN 931 bolts offer the necessary strength and durability.
Conclusion
Both DIN 933 and DIN 931 bolts are critical components in various engineering and construction applications. Understanding the differences between these two types of bolts will help you make the right choice for your project, ensuring strong, reliable, and safe connections. Whether you need full threading for adjustability or partial threading for enhanced shear strength, DIN 933 and DIN 931 bolts provide the quality and performance required in demanding environments.
We stock and can supply DIN 933 and DIN 931 bolts in various threads, materials and finishes.
Give us a call 0151 355 8045 or email sales@leytonfasteners.co.uk for more information and to discuss your requirements.