Introduction
When working on mechanical builds, construction fixtures or custom assemblies, choosing the right threaded rod or stud bolt can make all the difference. In this guide, we explain what those M-series sizes mean, how to choose the right one and how to ensure reliable performance.
1. What Are Metric Threaded Fasteners?
Metric threads are standardized fasteners defined by ISO and indicated using the “M” prefix followed by diameter. For example, M8 means the threaded rod’s major diameter is approximately 8 mm.
Unlike imperial fasteners, metric systems define thread pitch in millimeters — which simplifies caliper and drill calculations.
2. Understanding M3-M10 Sizes
| Thread | Diameter | Common Uses |
|---|---|---|
| M3 | 3 mm | Electronics, small assemblies |
| M4 | 4 mm | Fixtures, light equipment |
| M5 | 5 mm | General machinery |
| M6 | 6 mm | Automotive, industrial |
| M8 | 8 mm | Construction, tools |
| M10 | 10 mm | Heavy-duty fastenings |
Each size increases load capacity and strength. Smaller ones are great for precision tech or electronics, while larger sizes handle structural loads.
3. How to Choose the Right Threaded Rod
Material: Stainless steel is ideal for moisture-rich environments.
Length & Pitch: Ensure you select proper thread pitch and length for your nuts or assembly needs.
Surface Treatment: Hot-dip galvanized or plated rods are better for outdoor corrosion resistance.
4. Installation Tips
Use proper wrenches or sockets sized to fit metric nuts.
Apply anti-seize lubricant if used in corrosive environments.
Ensure threaded engagement is at least 1.5× diameter for load applications.
5. Maintenance & Best Practices
Inspect fasteners periodically for loosening.
Use thread locking compounds where vibration is common.
Conclusion & Call-to-Action
Metric threaded rods from M3 to M10 are versatile components essential for reliable assembly across industries. Explore our precision stainless steel fastener kits — engineered to help your projects succeed.
👉 Shop now and stock your workshop with quality metric fasteners.