M8 M10 M12 Square Head Bolts Full Threaded 304 Stainless Steel 12–100mm

A general rule is to select a bolt length equal to the thickness of the material being fastened plus at least 1–1.5× the thread diameter for nut engagement. For example, joining two 10mm plates with an M8 bolt typically calls for a length of 25–30mm (about 1–1.2"). Available lengths range from 12mm (≈0.47") to 100mm (≈3.94"). When in doubt, size up — extra thread length is easier to manage than insufficient engagement.

These bolts are Grade 6.8, which generally provides a tensile strength of approximately 600 MPa and a proof load of around 480 MPa. Actual load capacity depends on the thread size, engagement length, and application conditions. For safety-critical structural applications, consult a qualified engineer to verify suitability.

Yes. Made from 304 stainless steel, these bolts offer good corrosion resistance in most outdoor environments including rain, humidity, and mild coastal conditions. For highly aggressive marine or chemical environments, 316 stainless steel is generally recommended. In standard outdoor construction — pergolas, fencing, decking hardware — 304 SS typically performs well long-term.

These are metric coarse-thread bolts conforming to ISO 68-1. M8 typically has a 1.25mm pitch, M10 a 1.5mm pitch, and M12 a 1.75mm pitch. They are compatible with any standard metric hex nut, flange nut, or coupling nut of the matching thread size and pitch — no special hardware required.

Square head bolts are driven with an open-end wrench, box wrench, or adjustable wrench sized to the head flats. They are not designed for socket drivers or screwdrivers. The square head provides excellent grip and resists cam-out, making them well-suited for high-torque applications where a hex head might round off.

Yes, these are fully threaded bolts — the thread runs the entire length of the shank from just under the head to the tip. This makes them ideal for applications where maximum thread engagement is needed, or where the bolt passes completely through a nut without requiring a smooth shank section for shear resistance.

Divide the millimeter value by 25.4 to get inches. Quick reference: 12mm ≈ 0.47", 20mm ≈ 0.79", 25mm ≈ 0.98", 30mm ≈ 1.18", 40mm ≈ 1.57", 50mm ≈ 1.97", 60mm ≈ 2.36", 80mm ≈ 3.15", 100mm ≈ 3.94".