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

  • Efficient Face Projection Welding Bolt

    Efficient Face Projection Welding Bolt

    The integrity of the joint formed by a Efficient Face projection welding bolt is verified through standard destructive or non-destructive testing methods. For over 15 years, Xiaoguo® has built a reputation among manufacturers for reliable quality and competitive pricing.
  • Type A Plastic Plugs Fine Thread

    Type A Plastic Plugs Fine Thread

    Our company Baoding Xiaoguo Intelligent Equipment Co., LTD. was set up formally in 2012, as one of the professional Type A plastic plugs Fine thread manufacturer and China Type A plastic plugs Fine thread factory, we are strong strength and complete management. Also, we have own exporting license. We mainly deal in making a series of Type A plastic plugs Fine thread and welcome to buy Type A plastic plugs Fine thread from us. Every request from customers is being replied within 24 hours.
  • Integrated Flange Hexalobular Head Flange Bolts

    Integrated Flange Hexalobular Head Flange Bolts

    A key advantage of Integrated Flange Hexalobular Head Flange Bolts is their resistance to cam-out, ensuring a secure and undamaged installation. Xiaoguo® supplies a full range of fasteners to manufacturers across the globe.
  • High Tensile Galvanized Billet Steel Wire

    High Tensile Galvanized Billet Steel Wire

    High Tensile Galvanized Billet Steel Wire, made in our factory, is a key offering from Xiaoguo®. We provide customized wire rod solutions in various diameters and zinc coating weights for different applications; compared to electroplated wire, it has a thicker, more robust coating, less prone to damage during handling and installation.
  • Flat Head Rivets

    Flat Head Rivets

    Flat head rivets are welded onto metals using the electric arc welding method, and they are very sturdy. They are suitable for metal manufacturing, mechanical maintenance or construction industries.Xiaoguo® uses weldable steel to produce this rivet, which is durable.
  • Hexagon Head Bolts with Flat Flange

    Hexagon Head Bolts with Flat Flange

    Our Xiaoguo® products offer high-quality hexagon head bolts with flat flange.The head adopts a flange structure design, which improves the sealing performance and reduces the number of components used. Our products are produced strictly in accordance with quality standards. Each bolt has been carefully inspected, so you can use them with confidence.

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