4.8 grade bolts

When it comes to high-strength fastening solutions, few options match the reliability and durability of 4.8 grade bolts. These bolts are engineered for general-purpose applications where moderate strength and excellent corrosion resistance are required. A key advantage is their versatility; they can be used in construction, machinery assembly, automotive repairs, and various DIY projects. For enhanced protection against rust and environmental factors, many users opt for our Zinc Plated Hexagon Bolt. The zinc plating provides a protective layer that significantly extends the bolt’s lifespan, making it ideal for outdoor or humid conditions. Similarly, our standard Hexagon Bolt offers a cost-effective solution for indoor applications where additional coating is not necessary. Both types are designed with a hexagonal head for easy installation using common wrenches or sockets, ensuring a secure and tight fit every time.


The 4.8 grade bolt is characterized by its mechanical properties and precise dimensions, which adhere to international standards such as ISO 898-1 and ASTM A307. Below is a detailed breakdown of the key parameters and specifications for the 4.8 grade bolt product line. This information helps engineers, procurement specialists, and DIY enthusiasts select the right fastener for their specific needs.

Key Mechanical Properties

  • Tensile Strength: 400 MPa minimum
  • Yield Strength: 320 MPa minimum
  • Elongation: 22% minimum
  • Hardness: 70-95 HRB (Rockwell B Scale)
  • Proof Load: 225 MPa

Material and Coating Specifications

Property Specification
Material Low Carbon Steel (Grade 4.8)
Coating Options Zinc Plated, Plain (Uncoated), Hot-Dip Galvanized
Coating Thickness (Zinc) 5-8 µm
Corrosion Resistance Salt Spray Test: 72-120 hours (Zinc Plated)
Finish Bright, Electroplated Finish

Standard Dimensions (Hexagon Head Bolts)

Diameter (mm) Pitch (mm) Head Width Across Flats (mm) Head Height (mm) Common Lengths (mm)
M6 1.0 10 4 10, 12, 16, 20, 25, 30
M8 1.25 13 5.3 16, 20, 25, 30, 35, 40
M10 1.5 17 6.4 20, 25, 30, 35, 40, 45, 50
M12 1.75 19 7.5 25, 30, 35, 40, 45, 50, 60
M16 2.0 24 10 30, 35, 40, 45, 50, 60, 70, 80

Applications and Usage Guidelines

  • General Construction: Suitable for light to medium structural connections, framing, and scaffolding.
  • Machinery and Equipment: Ideal for assembling machinery parts, motor mounts, and conveyor systems.
  • Automotive: Used in non-critical automotive components, brackets, and accessories.
  • DIY and Home Improvement: Perfect for furniture assembly, fence building, and general repairs.
  • Installation Torque: Recommended torque values range from 10 Nm for M6 bolts to 150 Nm for M16 bolts, depending on lubrication and thread condition.

Hot Products

  • Precision Single Chamfer Hex Nut

    Precision Single Chamfer Hex Nut

    The Xiaoguo®precision single chamfer hex nut has been fully processed and features a single chamfer, allowing the nut to slide smoothly into the bolt. They are often used in precision mechanical assembly or furniture manufacturing. Xiaoguo® ensures that each nut meets strict standards.
  • Slipknot Bolts

    Slipknot Bolts

    Xiaoguo® manufacturer provides on-site fastener training for distributors covering installation best practices. When you're taking care of Slipknot Bolts, you've got to lube it up right and make sure the torque is set correctly. This stops it from wearing out too fast and keeps it working well for a long time.
  • Acorn Hexagon Nuts with Fine Thread

    Acorn Hexagon Nuts with Fine Thread

    Xiaoguo®’s acorn hexagon nuts with fine thread great for industrial use. Buy in bulk or check our price list. These nuts fit standard needs, tough for long use. Also support customized orders. Contact us to start your wholesale purchase hassle-free.
  • Permanently Anchored Countersunk Head Riveted Nuts

    Permanently Anchored Countersunk Head Riveted Nuts

    Permanently Anchored Countersunk Head Riveted Nuts are permanent fasteners that provide a strong, flush-mounting threaded insert in sheet materials. As a reliable supplier, Xiaoguo® utilizes a wide array of materials—from stainless steel to titanium—to suit any application related to such fasteners.
  • Type B 12 Piont Flange Screws

    Type B 12 Piont Flange Screws

    Type B 12 piont flange screws are specially designed for projects that require additional stability. It is easier for you to control when tightening. The flange base can distribute the pressure and prevent damage. Xiaoguo® Company has a rich inventory. You can contact us at any time.
  • Double Ends Anchor Bolt

    Double Ends Anchor Bolt

    Double ends anchor bolts are crucial for firmly fixing structures. Both ends have threads. One end can be anchored in concrete or masonry structures, while the other end is used to fix equipment or fixtures. Xiaoguo® factory has a rich inventory and you can place orders at any time.

Send Inquiry

X
We use cookies to offer you a better browsing experience, analyze site traffic and personalize content. By using this site, you agree to our use of cookies. Privacy Policy
Reject Accept