Grades and Material Strength

We manufacture carriage bolts in grades 8.8, 10.9, and 12.9, giving customers the flexibility to choose based on the load and stress conditions of their application. Grade 8.8 is commonly used for general structural and machinery work, while 10.9 and 12.9 are selected for higher tensile strength requirements in heavy machinery, automotive assemblies, and load-bearing structures. All bolts are manufactured to conform with ISO 2609 standards, ensuring consistent head shape, neck dimensions, and thread quality across every batch.

Coatings for Corrosion Resistance

Depending on the environment the bolt will be used in, we offer the following coating options:

• Zinc Phosphate – for base-level corrosion protection and better paint adhesion.
• Manganese Phosphate – suited for parts needing additional wear resistance.
• Zinc Electroplating (Hexavalent or Trivalent Chrome) – for a bright finish with good corrosion resistance, commonly used in automotive and general engineering.
• ZAC (Zinc Aluminium Flake Coating) – for superior corrosion resistance in harsh or outdoor environments without the risk of hydrogen embrittlement.

Choosing the right coating matters as much as choosing the right grade—a bolt with the correct strength but the wrong coating can still fail prematurely due to rust or environmental exposure. Our team can help guide this selection based on where and how the bolt will be used.

Custom Fasteners on Request

Beyond standard carriage bolts, NEW STAR Industries manufactures all types of fasteners as per customer specifications, including custom diameters, lengths, head types, and coatings. If your application requires a non-standard size or a specific finish, our engineering team can manufacture according to your drawings or samples.

For bulk orders, technical drawings, or coating recommendations, get in touch with our team directly.