Bolt steglängd

Table of Contents

Bolts are essential fasteners in construction, machinery, and various engineering fields. The reliability and performance of bolts depend heavily on their grade, which indicates their material properties, strength, and intended applications. Understanding bolt grades is vital to ensure safety and performance in any project. This article explores the concept of bolt grades, their classifications, and how to choose the right one for your needs.

What are Bolt Grades

Bolt grades are a standardized way of categorizing bolts based on their mechanical properties, such as tensile strength, yield strength, and hardness. These grades ensure that bolts meet the specific demands of different applications. Bolt grades are typically determined by two main standards:

• Metric System (ISO): Common worldwide, used for metric bolts.
• Imperial System (SAE): Common in the United States and for imperial bolts.

Key Features

• Strength: Bolt grades specify the tensile strength (the maximum force a bolt can endure before breaking) and yield strength (the force at which a bolt deforms permanently).
• Material: Different grades corres

  Eurocode 3 Table of design properties for metric hexagonal bolts M5 to M39 (stress area, shear strength, tensile strength, bearing strength)

  Definition of standard metric bolts

  The standarized properties of metric bolts are specified in the international standard ISO 'Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screws and studs with specified property classes - Coarse thread and fine pitch thread'. According to ISO the bolts are characterized depending on their pitch thread:

  • Coarse pitch thread: For general applications coarse pitch thread bolts are used. They are designated by their nominal diameter d in mm prefixed by the letter 'M'. The standard coarse pitch thread metric bolt sizes are: M3, M, M4, M5, M6, M7, M8, M10, M12, M14, M16, M18, M20, M22, M24, M27, M30, M33, M36, M
  • Fine pitch thread: For special applications fine pitch thread bolts may be used. They are designated as above also including the pitch of thread in mm e.g. M8 × 1, M14 × , M27 × 2 etc. In general the stress area of fine pitch thread bolts passing through the threaded part is larger as compared to the coarse pitch thread bo

    EN Specifications for Fasteners Materials

    • Specification for hot rolled non alloy structural steels.
    • Specification for hot rolled normalized/normalized rolled weldable fine grain structural steels.
    • Specification for hot rolled thermomechanically rolled weldable fine grain structural steels.
    • Specification for hot rolled structural steels with improved atmospheric corrosion resistance.
    • Specification for hot rolled quenched and tempered structural steel flat products with high yield strength.
    • Specification for flat products made of non-alloy and alloy steels with specified elevated temperature properties.
    • Specification for flat products made of weldable fine grain normalized steels.
    • Specification for flat products made of nickel alloy steels with specified low temperature properties.
    • Specification for flat products made of weldable fine grain rolled steels.
    • Specification for flat products made of weldable fine grain quenched and tempered steels.
    • Specification for flat products made of stainless steels.
    • Specification for quenched and tempered special steels.
    • Specification for quenched and tempered unalloyed quality steels.
    • Specification f

      .

      .