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The Range£9.79Visit shop Unifix Grade 12.9 Socket Head Cap Screws M5 X 30 - Box Of 200 - Grey
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The Unifix Grade 12.9 Socket Head Cap Screws are engineered for professionals and DIY enthusiasts requiring maximum tensile strength for critical assembly and heavy-duty projects. Manufactured to the stringent DIN 912 standard, these screws provide exceptional reliability in high-stress engineering and construction environments; however, users should be aware that their high-carbon steel composition makes them susceptible to corrosion if not properly treated or kept in humid, unprotected conditions.
| Colour | Grey |
|---|---|
| Model Part Number | DIN 912 |
| Brand | Unifix |
The 12.9 rating refers to the mechanical properties of the steel. It indicates a nominal tensile strength of 1200 MPa and a yield strength of 90% of the nominal tensile strength (1080 MPa).
While they are very strong, they are made of alloy steel and will rust when exposed to moisture. If used outdoors, they should be coated with an anti-corrosive substance or checked frequently.
Yes, because these are made from heat-treated alloy steel, they will be magnetic.
DIN 912 is a technical standard for hexagonal socket head cap screws, defining specific head dimensions, thread types, and tolerances.
For critical applications where specific clamping force is required, a torque wrench is highly recommended to ensure you reach the correct preload without exceeding the screw's strength limit.
If a screw has been tightened to its yield point or shows any signs of thread deformation, stretching, or head damage, it should be replaced for safety.
Ensure you are using a high-quality, properly sized metric hex key and that it is fully seated in the socket before applying torque.
Check that the threads of both the screw and the hole are clean and free of debris. Ensure the thread pitch matches exactly.
Clean the affected area with a wire brush and apply a thin layer of machine oil or corrosion-resistant spray to prevent further oxidation.
To ensure peak performance, always match the thread pitch of the screw with the corresponding tapped hole. Avoid over-torquing beyond the material's yield point, which can cause snapping. Because these are high-strength alloy steel, they are susceptible to rust if stored in damp areas or left exposed to the elements. For long-term installations in non-corrosive environments, a light application of machine oil or an anti-seize lubricant on the threads is recommended to prevent seizing over time. If using in outdoor or marine environments, regular inspection for surface rust is necessary, or you should consider applying a protective coating or rust inhibitor immediately after installation.
