Din 6935 Standard Pdf
is the fundamental German industrial standard for the cold bending of flat rolled steel products
. It is widely used in mechanical engineering and steel construction to calculate the precise developed length
—the exact size of a flat metal sheet before it is bent into its final shape. CaldereriaOnLine.com Why DIN 6935 Matters
When sheet metal is bent, the outer surface stretches and the inner surface compresses. To ensure the final part has the correct dimensions, designers must calculate a compensation value that accounts for these material changes. Key Specifications Bending Radius:
The standard provides tables for the minimum permissible bending radii based on the material's thickness ( ) and steel grade (e.g., S 235 JR). Developed Length Calculation:
It defines how to calculate the unfolded length by summing the linear leg lengths and subtracting compensation values ( Rolling Direction:
It emphasizes bending transverse (across) the rolling direction to prevent cracking and achieve higher quality. Bending Angles: Guidelines cover angles from 0° up to 180°. Minimum Bend Length: Recommends a minimum length of at least the bending radius ( ) to ensure consistent results. Modulus Metal Example Calculation
To find the developed length of a part with three legs (50mm, 200mm, and 80mm) with two 90° bends: Sum of Leg Lengths: Calculate Compensation ( Based on sheet thickness and radius (e.g., Final Length: Modulus Metal
For professional application, you can view technical summaries or find the full DIN 6935 Standard PDF on platforms like Modulus Metal ANSI Webstore for a particular bending angle? DIN 6935 Cold Bending Guidelines | PDF - Scribd
Introduction
The DIN 6935 standard is a widely recognized specification in the steel industry, outlining the technical delivery conditions for hot rolled steel strip used in cold forming applications. This standard is essential for ensuring the quality and reliability of steel products used in various industries, including construction, automotive, and manufacturing.
Scope and Application
The DIN 6935 standard applies to hot rolled steel strips with a thickness range of 3 mm to 25 mm and a width range of 600 mm to 2,050 mm. These steel strips are used for cold forming applications, such as bending, folding, and profiling, to produce various shapes and structures. The standard covers the technical delivery conditions for these steel strips, including their chemical composition, mechanical properties, and surface quality.
Chemical Composition
The DIN 6935 standard specifies the chemical composition of the steel strips, including the maximum allowed percentages of carbon, manganese, silicon, and other elements. The standard also defines the acceptable limits for impurities, such as sulfur and phosphorus. The chemical composition of the steel strips is critical in determining their weldability, formability, and mechanical properties.
Mechanical Properties
The standard outlines the mechanical properties of the steel strips, including their yield strength, tensile strength, and elongation. These properties are essential in determining the steel strips' ability to withstand various types of loading, such as bending, stretching, and impact. The standard also specifies the testing methods and conditions for determining these mechanical properties.
Surface Quality
The DIN 6935 standard defines the surface quality requirements for the steel strips, including the acceptable limits for surface defects, such as cracks, seams, and rust. The standard also specifies the testing methods for evaluating the surface quality of the steel strips.
Benefits and Importance
The DIN 6935 standard offers several benefits to manufacturers, designers, and users of steel products. By specifying the technical delivery conditions for hot rolled steel strips, the standard ensures that these products meet the required quality and reliability standards. This, in turn, enables the production of high-quality steel products with consistent properties, which is critical in ensuring the safety and performance of various structures and applications.
Conclusion
In conclusion, the DIN 6935 standard is a critical specification in the steel industry, outlining the technical delivery conditions for hot rolled steel strip used in cold forming applications. The standard covers the chemical composition, mechanical properties, and surface quality of these steel strips, ensuring that they meet the required quality and reliability standards. By adhering to this standard, manufacturers and users of steel products can ensure the production of high-quality products with consistent properties, which is essential in ensuring the safety and performance of various structures and applications.
standard, titled "Cold bending of flat rolled steel" , is a technical regulation that establishes guidelines for the cold bending of sheet metal and flat steel products
. It is primarily used in mechanical engineering and steel construction to ensure precision and prevent material failure during fabrication Core Content of DIN 6935
The standard provides a systematic approach to calculating the dimensions of a part before it is bent, ensuring the final product meets specified measurements Minimum Bending Radii
: Specifies the smallest radius a specific steel grade can be bent without cracking or compromising structural integrity Developed Length Calculation
: Explains how to determine the "stretched" or "unfolded" length of a part by using compensation values ( ) and correction factors ( Neutral Fiber Deviations
: Accounts for how the material's "neutral axis" shifts during the bending process, which affects the final length of the legs Permissible Deviations
: Outlines the legal tolerances for bending angles and radii to maintain quality control in manufacturing Technical Applications Material Selection
: Includes tables categorizing different steel grades and their suitability for cold bending Design Guidelines
: Recommends selecting bending radii from a preferred series to ensure uniformity across different fabrication setups Modulus Metal Minimum Leg Length
: Defines the minimum distance required between a bend and the edge of the sheet to allow for proper tooling engagement Accessing the Standard
As with most DIN (Deutsches Institut für Normung) standards, the full official text is a copyrighted document. You can find official copies and related technical supplements through the following types of sources: Official Purchase
: The complete updated standard (latest version often cited as DIN 6935:2011-10 ) can be purchased through the or authorized distributors like Beuth Verlag Technical Previews
: Summary guides and tables of the standard's calculations are often available on professional platforms like or specialized engineering sites like Modulus Metal under this standard? DIN 6935: Cold Bending Steel Standards | PDF - Scribd
The DIN 6935 Standard: A Comprehensive Guide to Spring Washers and Disc Springs
The DIN 6935 standard is a widely recognized and respected specification in the engineering and manufacturing industries, particularly in the design and production of spring washers and disc springs. This standard, published by the German Institute for Standardization (DIN), provides detailed guidelines for the design, materials, and testing of spring washers and disc springs used in various applications.
In this article, we will provide an in-depth overview of the DIN 6935 standard, its significance, and its relevance to the engineering and manufacturing industries. We will also discuss the key aspects of spring washers and disc springs, their applications, and the importance of adhering to the DIN 6935 standard.
What is DIN 6935?
DIN 6935 is a German standard that specifies the requirements for spring washers and disc springs, including their design, materials, and testing. The standard covers various types of spring washers and disc springs, including:
- Spring washers (also known as spring lock washers)
- Disc springs (also known as Belleville washers)
- Stacked disc springs
The DIN 6935 standard provides detailed specifications for the design, dimensions, materials, and testing of these components, ensuring that they meet the required performance and safety standards.
Significance of DIN 6935
The DIN 6935 standard is significant in the engineering and manufacturing industries for several reasons: Din 6935 Standard Pdf
- Interchangeability: The standard ensures that spring washers and disc springs from different manufacturers are interchangeable, reducing the risk of compatibility issues and facilitating maintenance and repair.
- Quality and Reliability: The standard guarantees that spring washers and disc springs meet specific quality and performance requirements, ensuring reliability and safety in various applications.
- Design and Development: The standard provides a framework for designers and engineers to develop new products and applications, ensuring that spring washers and disc springs are used effectively and efficiently.
Key Aspects of Spring Washers and Disc Springs
Spring washers and disc springs are critical components in various applications, including:
- Spring Washers: Spring washers are used to provide a spring force in a bolted connection, helping to maintain the connection's integrity and preventing loosening.
- Disc Springs: Disc springs are used to provide a high spring force in a compact design, often used in applications where space is limited.
The key aspects of spring washers and disc springs include:
- Materials: Spring washers and disc springs are typically made from high-strength materials, such as steel or stainless steel, to ensure durability and resistance to corrosion.
- Design: The design of spring washers and disc springs is critical to their performance, including factors such as thickness, diameter, and curvature.
- Testing: Spring washers and disc springs must undergo rigorous testing to ensure they meet the required performance and safety standards.
Applications of Spring Washers and Disc Springs
Spring washers and disc springs are used in a wide range of applications, including:
- Aerospace: Spring washers and disc springs are used in aircraft and spacecraft to provide critical connections and ensure structural integrity.
- Automotive: Spring washers and disc springs are used in vehicle suspension, steering, and braking systems.
- Industrial: Spring washers and disc springs are used in machinery, equipment, and appliances to provide critical connections and ensure smooth operation.
Importance of Adhering to DIN 6935
Adhering to the DIN 6935 standard is crucial for several reasons:
- Safety: Spring washers and disc springs that meet the DIN 6935 standard ensure safety in various applications, reducing the risk of failure and accidents.
- Performance: Spring washers and disc springs that meet the DIN 6935 standard ensure optimal performance, including factors such as spring force, durability, and resistance to corrosion.
- Compliance: Adhering to the DIN 6935 standard ensures compliance with regulatory requirements and industry standards.
Downloading DIN 6935 Standard PDF
The DIN 6935 standard PDF can be downloaded from various sources, including:
- DIN Website: The official DIN website provides access to the DIN 6935 standard PDF, along with other standards and specifications.
- Standards Libraries: Many standards libraries and databases provide access to the DIN 6935 standard PDF, often with additional resources and information.
- Online Marketplaces: Online marketplaces, such as IHS Standards Store or ANSI Webstore, provide access to the DIN 6935 standard PDF, often with translation and customization options.
Conclusion
The DIN 6935 standard is a critical specification in the engineering and manufacturing industries, providing detailed guidelines for the design, materials, and testing of spring washers and disc springs. Adhering to this standard ensures safety, performance, and compliance with regulatory requirements and industry standards.
By understanding the significance and key aspects of the DIN 6935 standard, engineers, designers, and manufacturers can ensure that spring washers and disc springs meet the required performance and safety standards, ultimately contributing to the development of high-quality products and applications.
Recommendations
- Engineers, designers, and manufacturers should familiarize themselves with the DIN 6935 standard and its requirements.
- Spring washers and disc springs should be designed, manufactured, and tested in accordance with the DIN 6935 standard.
- The DIN 6935 standard PDF should be downloaded from reputable sources to ensure accuracy and authenticity.
By following these recommendations, industries can ensure that spring washers and disc springs meet the required performance and safety standards, ultimately contributing to the development of high-quality products and applications.
standard is a critical reference for engineers and fabricators involved in the cold bending of flat-rolled steel. It provides a standardized framework for determining how metal behaves when bent, ensuring that final dimensions are accurate after the sheet is flattened or "developed". Key Specifications of DIN 6935 Bending Parameters : The standard covers bending angles typically ranging from 0 raised to the composed with power 180 raised to the composed with power Minimum Bending Radii
: It specifies the smallest allowable radii based on steel grade and thickness to prevent cracking. Material Behavior
: During bending, the material thickness in the rounded portion can reduce by up to Rolling Direction
: For best results, bending should ideally be performed transverse (perpendicular) to the rolling direction of the steel to avoid structural failure. Calculating Developed Length One of the primary uses of DIN 6935 is calculating the stretched length
) of a part before it is bent. This is done using a compensating value (
) that accounts for the shift in the "neutral fiber" of the material. A common simplified formula for the developed length is: leg lengths cap L equals sum of leg lengths plus sum of v
(the compensation value) is determined by the bending angle and the ratio of the internal radius ( ) to the material thickness ( Permissible Deviations
The standard also outlines how much a bend can deviate from the intended radius depending on the steel grade: Steel Grade Thickness up to 3mm Thickness 3mm to 8mm S235 (JR/JO/J2) S275 (JR/JO/J2) S355 (JR/JO/J2) Where to Access the Standard While the full official document must be purchased from
or authorized distributors, technical summaries and partial translations are often hosted on engineering platforms: frequently hosts English translations and guidelines. Modulus Metal
provides concise tables for minimum bending radii and deviations. for a particular material thickness? DIN 6935 Cold Bending of Flat Rolled Steel - Modulus Metal
Mastering Cold Bending: A Deep Dive into the DIN 6935 Standard
If you're in steel construction or mechanical engineering, you've likely encountered the complexities of bending flat rolled steel. Getting the dimensions right before the first hit of the press brake is critical to avoiding waste and ensuring structural integrity. This is where the DIN 6935 standard becomes an essential tool for your workshop or design office. What is the DIN 6935 Standard?
Released by the German Institute for Standardization (DIN), DIN 6935 (specifically the 2011-10 version) provides the technical framework for the cold bending of flat rolled steel products. It establishes guidelines for: Minimum bending radii to prevent material failure. Permissible deviations in angles and positions.
Calculation of developed lengths (the "unfolded" length of a part). Key Technical Insights
The standard isn't just a list of rules; it's a mathematical approach to precision fabrication. 1. Minimum Bending Radii Selecting the correct radius (
) is vital to maintain material strength. DIN 6935 provides tables based on material thickness ( ) and steel grade. Angle Sensitivity: For bending angles , specific standard radii apply. If the angle exceeds 120∘120 raised to the composed with power
, you must move to the next higher value in the table to account for increased stress.
Rolling Direction: The standard distinguishes between bending transverse (perpendicular) or parallel to the material's rolling direction, as this affects the metal's ductility. 2. The Compensation Value (
One of the most valuable parts of the standard is how it handles the neutral fiber—the line in the material that doesn't stretch or compress during bending. The standard uses a compensation value ( ) to adjust the total leg length. Formula Logic: Depending on the opening angle, can be positive or negative. For angles over 65∘65 raised to the composed with power , the compensation value is typically negative. 3. K-Factor and Material Behavior DIN 6935 defines a correction factor (
) that indicates the shift in the neutral fiber position. While standard formulas often use a
(center of the sheet), DIN 6935 provides more granular values to ensure that your flat patterns match the final bent part within a millimeter. Where to Find the DIN 6935 PDF
Because this is a copyrighted technical standard, it is typically purchased through official standards bodies:
European Standards Store: Offers the English and German PDF versions for approximately €70–€90. Beuth Verlag: The official publisher for DIN standards.
Educational Summaries: Many engineering sites like Modulus Metal provide helpful table summaries and calculation examples for quick reference. Why It Matters
Using the DIN 6935 standard eliminates the "guess-and-check" method in sheet metal work. By following its calculated compensation values and minimum radii, you reduce material cracking, improve part accuracy, and ensure your designs are up to international industrial specs. DIN 6935 Cold Bending of Flat Rolled Steel - Modulus Metal
The DIN 6935 standard is a critical technical guideline for the cold bending of flat rolled steel products. Primarily used in mechanical engineering and steel construction, it provides the standardized formulas and tables required to calculate "developed lengths"—the length of a flat sheet before it is bent into its final shape. Key Specifications of DIN 6935
The standard outlines several parameters essential for precise sheet metal fabrication: Bending Radius (
): Recommends specific radii from the DIN 250 series (e.g., 1, 1.2, 1.6, 2, 2.5 mm) to ensure uniform curves across different machinery.
Minimum Leg Length: For mechanical bending, the standard suggests a minimum leg length ( ) of approximately 4 times the bending radius ( ) to prevent defects. Thickness Reduction: It accounts for a material thickness ( is the fundamental German industrial standard for the
) decrease of approximately 20% in the rounded portion of the bend.
Rolling Direction: Bending should ideally be carried out transverse (perpendicular) to the rolling direction of the steel to reduce the risk of cracking. Calculation of Developed Lengths
The core utility of the DIN 6935 standard is its method for determining the unfolded length of a part using the formula:
Developed Length=a+b+vDeveloped Length equals a plus b plus v are the leg lengths, and is a compensating value. Opening Angle ( Compensating Value ( 0∘0 raised to the composed with power 90∘90 raised to the composed with power
Calculated using a specific formula involving radius, thickness, and a correction factor ( 90∘90 raised to the composed with power 165∘165 raised to the composed with power
Calculated with a modified formula to account for larger opening angles. 165∘165 raised to the composed with power 180∘180 raised to the composed with power The compensating value is considered negligible ( Correction Factor ( The correction factor represents the shift of the neutral fiber during bending. It is calculated as: For ratios where , the correction factor is simply set to . Where to Access the DIN 6935 Standard PDF
The official version is DIN 6935:2011-10, which superseded the 2010 edition. It can be acquired through authorized distributors: DIN 6935 Cold Bending of Flat Rolled Steel - Modulus Metal
Mastering Cold Bending: A Deep Dive into the DIN 6935 Standard
In the world of mechanical engineering and steel construction, precision isn't just a goal—it's a requirement. If you’ve ever wondered how manufacturers calculate the exact flat length of a piece of steel before it’s bent into a complex shape, you’ve likely come across the name DIN 6935.
This German standard is the "gold standard" for the cold bending of flat rolled steel products. It provides the mathematical framework and physical guidelines necessary to ensure that bent parts are accurate, structurally sound, and free from cracks or deformities. What Exactly is DIN 6935?
The DIN 6935 Standard focuses on the cold bending process. Unlike hot bending, which uses heat to make metal more pliable, cold bending is done at room temperature. This requires a precise understanding of material behavior, as the steel must stretch and compress without failing. The standard covers several critical areas:
Minimum Bending Radii: Tables that specify the smallest allowable radius for a bend based on the material's thickness ( ) and grade.
Permissible Deviations: Limits on how much the final angle or radius can differ from the design.
Calculation of Developed Lengths: The formulas used to determine the "unfolded" length of a part. The Secret Sauce: The K-Factor and Compensation
One of the biggest challenges in bending is that the "neutral fiber" (the layer of metal that neither stretches nor compresses) shifts during the process.
According to insights from the Autodesk Community, DIN 6935 uses a specific K-Factor to account for this shift. If you don't calculate this correctly, your finished part will be either too long or too short. Key technical takeaways include:
Equation Validity: The standard equations for the K-factor are generally valid for a radius ( ) to thickness (
) ratio up to 5; beyond this, the factor is typically set to Compensation Values: For opening angles over 65∘65 raised to the composed with power
, compensation values are typically negative, meaning the material "grows" more than expected.
Rounding: It is industry practice to round stretched lengths to the nearest millimeter for manufacturing simplicity. Why You Need the PDF Guidelines
If you are a designer or a CNC operator, having a copy of the DIN 6935 Cold Bending Guidelines is essential. These documents include:
Material Tables: Specific data for different steel grades (e.g., S235, S355).
Visual Diagrams: Clear representations of how to dimension bent parts.
Step-by-Step Examples: Practice calculations to help you master the "compensation value" formulas. Summary Table: Quick Reference Specification Details Material Scope Flat rolled steel products (sheet and plate) Bending Angle ( ) Typically between 0∘0 raised to the composed with power 180∘180 raised to the composed with power Key Formula Component K-Factor (neutral axis shift) Common Application Mechanical engineering, automotive, and steel frames
💡 Pro Tip: When selecting a bending radius, always refer to the "bolded" values in the Scribd DIN 6935 Tables first. These are the preferred industry standards that offer the best balance between structural integrity and ease of manufacturing.
DIN 6935 is the primary German technical standard for the cold bending of flat steel products. It is widely used in steel construction and mechanical engineering to determine minimum bending radii, calculate the "developed length" (flat length) of parts before they are bent, and define permissible tolerances. 1. Key Technical Specifications
The standard provides a framework for ensuring structural integrity during the bending process:
Material Direction: It is recommended to bend transverse to the rolling direction whenever possible to avoid cracking and ensure a higher-quality bend.
Thickness Reduction: During the bending process, the material thickness in the rounded portion typically decreases by approximately 20%.
Minimum Leg Length: For mechanical bending, the minimum leg length ( ) is generally recommended to be at least (four times the bending radius). 2. Standard Bending Radii (
DIN 6935 suggests selecting radii from a standard series (1, 1.2, 1.6, 2, 2.5... up to 100 mm) to ensure uniformity. The minimum permissible radius depends on the steel grade and thickness ( S235 Steel ( mm): Minimum mm (transverse) or mm (parallel). S355 Steel ( mm): Minimum mm (transverse) or mm (parallel). High Angles: If the bending angle is
>120∘is greater than 120 raised to the composed with power
, you must use the next higher standard radius from the table. 3. Calculation of Developed Length
To find the total length of the flat sheet needed to create a bent part, use the formula:
Developed Length=a+b+vDeveloped Length equals a plus b plus v : Leg lengths.
(Compensating Value): An adjustment factor that accounts for material stretching or compression at the neutral fiber. Compensation Formulas ( Opening Angle ( Formula for 0∘0 raised to the composed with power 90∘90 raised to the composed with power
π⋅(180∘−β180∘)⋅(r+s2⋅k)−2(r+s)pi center dot open paren the fraction with numerator 180 raised to the composed with power minus beta and denominator 180 raised to the composed with power end-fraction close paren center dot open paren r plus s over 2 end-fraction center dot k close paren minus 2 open paren r plus s close paren 90∘90 raised to the composed with power 165∘165 raised to the composed with power
π⋅(180∘−β180∘)⋅(r+s2⋅k)−2(r+s)⋅tan(180∘−β2)pi center dot open paren the fraction with numerator 180 raised to the composed with power minus beta and denominator 180 raised to the composed with power end-fraction close paren center dot open paren r plus s over 2 end-fraction center dot k close paren minus 2 open paren r plus s close paren center dot tangent open paren the fraction with numerator 180 raised to the composed with power minus beta and denominator 2 end-fraction close paren 165∘165 raised to the composed with power 180∘180 raised to the composed with power Negligible (use Correction Factor (
-factor shifts the neutral line during bending and is calculated as:
k=0.65+0.5⋅log10(rs)k equals 0.65 plus 0.5 center dot log base 10 of open paren r over s end-fraction close paren Note: If the ratio 4. Permissible Deviations
The standard also outlines how much the final bend can deviate from the design:
Angular Position: For leg lengths up to 30 mm, a deviation of ±2∘plus or minus 2 raised to the composed with power is allowed. This tightens to ±1∘plus or minus 1 raised to the composed with power for leg lengths over 120 mm. Bending Radii: Deviations range from +0.5positive 0.5 mm (for thin S235cap S 235 sheets) to +3.0positive 3.0 mm (for thick S355cap S 355 Accessing the PDF
The full 13-page standard (DIN 6935:2011-10) is a copyrighted document. You can purchase official copies from the ANSI Webstore or Beuth Verlag. Unofficial English translations and summaries are often available on platforms like Scribd. DIN 6935 Cold Bending of Flat Rolled Steel - Modulus Metal Spring washers (also known as spring lock washers)
The DIN 6935 standard is a foundational technical document in metal fabrication, providing standardized guidelines for the cold bending of flat rolled steel products. It is essential for engineers and designers in steel construction and mechanical engineering, ensuring accuracy, consistency, and structural integrity when designing bent components.
Here is a comprehensive write-up on the DIN 6935 standard, its key components, and its practical application. 1. Overview and Scope Topic: Cold Bending of Flat Rolled Steel.
Purpose: To define specifications for minimum bending radii, permissible deviations, and calculations for developing bending lengths, primarily for steel sheet/strip.
Relevance: The standard is used for cold-formed steel parts to prevent cracking during manufacturing and to calculate the precise flat length (unfold) needed before bending. 2. Key Technical Guidelines (DIN 6935:2011-10)
Minimum Bending Radii: The standard provides tables specifying the minimum inside radius ( Ricap R sub i ) based on the material thickness (
) and the type of steel. Selecting a proper radius is crucial to preventing surface cracks and premature failure. Bending Angle ( ): Defines the external angle, which can range from 0∘0 raised to the composed with power 180∘180 raised to the composed with power
Rolling Direction: DIN 6935 emphasizes that, for optimal performance and to minimize cracking risk, bending should generally be performed perpendicular to the rolling direction of the sheet.
Permissible Deviations: It outlines acceptable tolerances for the bending radius and the final angular position, which are critical for precision engineering. 3. Developed Length Calculation (Unfolding)
One of the primary uses of DIN 6935 is calculating the developed length (
)—the total length of the flat sheet before it is bent. The formula allows for the extension of the material on the outside of the bend and compression on the inside. Formula: : Leg lengths of the bent part. : Compensating value (or correction factor). Compensating Value ( ): This value changes depending on the bending angle ( ) and the bending radius. If the opening angle is up to 65∘65 raised to the composed with power can be positive or negative. If the angle is over 65∘65 raised to the composed with power is typically negative. 4. Key Considerations for Fabrication
Material Thickness: The standard notes that thickness can change during the bend, particularly by up to lower at the bending point.
Surface Condition: The quality of the surface is essential. Edges of the sheet should be free of burrs or cuts, as these act as stress concentrators that can lead to edge cracking. 5. Accessing DIN 6935
Official Source: The full DIN 6935:2011-10 standard can be purchased from DIN or Scribd.
Documents: Many engineering resources provide simplified, English-translated versions that detail the bending guidelines and correction tables (e.g., Scribd or Modulus Metal).
View a table of minimum bending radii based on specific steel grades? Discuss how CAD software handles DIN 6935 calculations? DIN 6935: Cold Bending Steel Standards | PDF - Scribd
is the primary German technical standard governing the cold bending of flat rolled steel products
. It is widely used in mechanical engineering and steel construction to calculate developed (unfolded) lengths of sheet metal parts with high precision. Core Components of the Standard DIN 6935:2011-10
version provides a comprehensive framework for manufacturing accuracy: Minimum Bending Radii:
It specifies permissible radii based on material thickness and steel grade to prevent cracking and ensure structural integrity. Developed Length Calculation:
The standard uses a specific formula to determine the flat blank size required before bending: compensation value that accounts for material stretching. Compensation Values (
Unlike simpler methods that only use a constant K-factor, DIN 6935 provides tables and formulas for based on the opening angle ) and the ratio of bending radius to material thickness ( Permissible Deviations:
It outlines acceptable tolerances for both bending angles and radii, helping manufacturers maintain quality control during mass production. Modulus Metal Practical Review & Application Professional Review Summary
Higher than standard centerline methods because it adjusts for varied opening angles and material thickness. Material Scope
Best suited for structural steels (e.g., S235, S275, S355) bent transverse or parallel to the rolling direction. Design Guidance Recommends a minimum leg length of approximately
to ensure the bending machine can grip the material securely. Limitations
Some experts note that while widely used, it can be less precise for complex geometries compared to the Oehler method in specific software applications. Where to Access the PDF
Official versions are available through national standards bodies or authorized distributors: ANSI Webstore : Provides the full electronic PDF of the 2011 version. Beuth Verlag : The official publisher for DIN standards. Technical Summaries: Sites like Modulus Metal CaldereriaOnLine
offer helpful breakdowns and calculation examples for quick reference. ANSI Webstore calculation example
for a specific bend angle and material thickness using these DIN tables? DIN 6935 Cold Bending of Flat Rolled Steel - Modulus Metal
The Role of DIN 6935 in Precision Engineering The DIN 6935 standard is a critical technical framework that governs the cold bending of flat rolled steel products within the mechanical engineering and steel construction industries. Its primary function is to provide standardized methods for calculating "developed lengths" (the flat state of a part before it is bent) while ensuring structural integrity by specifying minimum bending radii. Core Technical Specifications
The standard provides engineers and manufacturers with precise guidelines to account for the physical changes steel undergoes during the bending process.
Minimum Bending Radii: To prevent material failure, such as cracking or excessive thinning, DIN 6935 defines permissible radii based on material thickness (
) and the specific grade of steel. For example, the radius must often be increased for bending angles exceeding 120∘120 raised to the composed with power to maintain material health.
Developed Length Calculation: When a flat sheet is bent, the outer surface stretches while the inner surface compresses. DIN 6935 introduces "compensating values" (
) and correction factors to accurately calculate the flat length required to achieve a finished bent component.
Material Thinning: The standard acknowledges that the thickness of the material decreases by approximately 20% in the rounded portion of the bend. Evolutionary Context
The current version of the standard is DIN 6935:2011-10, which replaced the 2010 edition and the much older 1975 and 1969 versions. While older versions like the 1969 edition are now considered inactive, they established the foundational tables for
factors that remain influential in legacy manufacturing workflows. Industrial Application DIN 6935: Cold Bending Steel Standards | PDF - Scribd
Please note: DIN 6935 has been withdrawn and superseded by the international standard DIN EN ISO 13722. This report reflects the historical relevance, technical content, and the transition to the current standard.
What is DIN 6935?
DIN 6935 is a German standard (Deutsches Institut für Normung) that provides the basis for the technical design and dimensioning of components made by bending sheet metal. It bridges the gap between the flat (unfolded) pattern and the finished (folded) 3D part.
Because sheet metal stretches on the outside of a bend and compresses on the inside, the length of the metal changes during the bending process. DIN 6935 provides the mathematical formulas and correction factors (specifically the "bending factor" or Biegefaktor) required to calculate the precise Flat Pattern Length.
4. Dimensional Tolerances Per DIN 6935
The standard also specifies strict tolerances for bent parts:
- Angular Tolerances: Typically ±30′ (minutes) up to ±2°, depending on the bending method and material strength.
- Length Tolerances: These are classified into "normal" and "fine" classes. For example, a 100 mm length on a 3 mm thick part might have a tolerance of ±0.5 mm for normal precision and ±0.2 mm for fine precision.
- Flatness and Straightness: Limits for twisting and warpage after bending.
3. The Bend Deduction ($u$)
Conversely, the standard allows for the calculation of bend deduction, which is the amount subtracted from the total outside dimensions of the part to arrive at the flat size.
2. Scope and Application
DIN 6935 applied to the cold bending of flat steel products (plates and sheets). Its primary objective was to provide guidelines to prevent material failure (cracking) and to ensure dimensional accuracy of the bent workpiece.
Key applications included:
- Construction of steel structures (bridges, buildings).
- Manufacturing of pressure vessels and tanks.
- General mechanical engineering components (brackets, frames, housings).
