When it comes to construction, engineering, and DIY projects, choosing the right fastener isn’t just about size and material—it’s also about strength. Understanding fastener strength ratings ensures that your structures remain safe and durable.
At Tradefix Fasteners, we supply high-quality fasteners that meet Australian standards for strength and reliability and our experienced team can help guide you toward the right fastener if you’re unsure.
Having said that, let’s take a look at strength ratings so you can get familiar yourself to start with.
Understanding Fastener Strength Ratings
Fastener strength ratings are typically measured in terms of tensile and shear strength, which determine how much load a bolt or screw can handle before failure. Different grading systems are used depending on the type of fastener and application.
Bolt Strength Grades
Bolts are classified based on their material composition and strength. Here are some common grading systems:
- Metric Bolts (ISO 898-1 Standard) – Common grades include 4.6, 8.8, 10.9, and 12.9. The first number represents the tensile strength in megapascals (MPa), while the second indicates the yield strength percentage.
- Grade 4.6: General-purpose applications, lower tensile strength.
- Grade 8.8: High-strength structural applications.
- Grade 10.9 & 12.9: Heavy-duty industrial use, such as machinery and automotive components.
- Imperial Bolts (SAE J429 Standard) – Common grades include Grade 2, 5, and 8.
- Grade 2: Low-carbon steel, suitable for non-critical applications.
- Grade 5: Medium-carbon steel, commonly used in automotive and construction.
- Grade 8: Heat-treated steel with superior tensile strength, ideal for heavy machinery.
Tensile vs. Shear Strength
- Tensile Strength: The maximum pulling force a fastener can withstand before breaking. Higher tensile strength is essential for load-bearing structures.
- Shear Strength: The force required to snap the fastener when forces are applied laterally. Shear strength is critical for applications such as joist hangers and decking.
Choosing the Right Fastener for Heavy-Duty Jobs
Selecting the right fastener depends on the load requirements, environmental conditions, and material compatibility. Here’s what to consider:
- Material Strength – Stainless steel and high-tensile steel bolts offer superior durability and resistance to breaking under stress.
- Corrosion Resistance – For outdoor or marine applications on the Gold Coast, galvanised and stainless steel fasteners prevent rust and degradation.
- Application-Specific Needs – Structural bolts, anchor bolts, and machine screws all have different load-bearing capabilities, so always check strength ratings before use.
Find the Right Fasteners at Tradefix Fasteners
At Tradefix Fasteners, we supply a wide range of high-strength fasteners designed to meet Australian standards. Whether you’re working on a construction site, fitting out a commercial space, or tackling a DIY project, our team can help you find the right solution.
For expert advice or trade account options for builders and developers, get in touch with our team today on 0421 311 227 or send us an email here.
Tradefix Fasteners is located in Currumbin, servicing all areas of the Gold Coast.
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