High-Tensile Steel Hex Bolt Grade 12.9, Size M20 Pitch 2.5, Full Thread with Class 10 Nut, Pack 1 Set(copy)(copy)

Detailed Specifications: Class 12.9 Black Oxide Hex Bolt with Class 10 Nut Set (Size M20-2.5)

1. Thread Specification

• Thread Diameter: M20 (20 mm shank diameter)
• Thread Pitch: 2.5 mm (Standard / Metric Coarse Thread)
• Thread Direction: Right-Hand Thread

2. Dimension Specification (Reference: DIN 933 / DIN 934)

• Bolt Head Height ($k$): 12.5 mm
  
• Nut Height ($m$): 16 mm
  
• Wrench Size / Width Across Flats ($s$): Size 30 mm (compatible with both the bolt head and hex nut)
  
• Head Style: Hexagon Head (available in various lengths depending on application)

3. Mechanical Specification

• Bolt Property Class: Grade 12.9 – The highest strength class for standard metric fasteners. Manufactured from quenched and tempered alloy steel.
  
• Tensile Strength: 1,200 N/mm² (1,200 MPa)
  
• Yield Strength: 1,080 N/mm² (1,080 MPa)
  
• Nut Property Class: Class 10 – Specially designed for high proof-load and high-torque applications paired with Class 10.9 and 12.9 bolts, preventing thread stripping under extreme tightening torque.
  
• Surface Finish: Black Oxide Finish with a light anti-rust oil coating for basic corrosion protection during storage and indoor use.
  

4. Suitable Applications

• Large Steel Structures & Foundations: Ideal for building steel structures, steel bridges, heavy machinery foundations carrying massive loads, and applications subjected to continuous high vibration.
  
• Extra Heavy Machinery: Suitable for large industrial machinery components, such as heavy hydraulic press machines, mining equipment, and heavy construction machinery.
  
• Heavy-Duty Vehicles: Commonly used in safety-critical mounting points, such as large engine mounts, heavy truck/trailer suspension systems, drive axles, and excavators/wheel loaders.
  
• Mold/Die Assembly & Energy Sector: Used for assembling large plastic injection/metal stamping die and mold sets, as well as securing high-pressure piping in power plants or petrochemical facilities.