Measure the total grip length — the thickness of the material you are bolting through — then add clearance for the nut and washer. For example, a 100mm (≈3.94") bolt is generally suitable for materials up to about 20mm thick when using a standard nut. The 70mm full-thread variant is ideal when you need maximum thread engagement in a tapped hole or with a deep nut. As a rule of thumb: L = material thickness + nut height + washer thickness + 2–3 thread pitches of protrusion.

Working load limits for M18 eye bolts typically range from 500 kg to over 1,000 kg depending on the alloy grade and loading angle. 304 stainless steel eye bolts are generally rated for vertical (axial) loads; side or angular loading significantly reduces safe working load. Always consult a structural engineer for safety-critical lifting or rigging applications, and never exceed the rated WLL.

304 stainless steel offers good corrosion resistance in most outdoor environments and is commonly used for catenary wire systems, garden structures, pergola rigging, and light marine applications. For highly saline or chloride-rich environments (e.g., direct ocean exposure or splash zones), 316 stainless steel is generally recommended for superior corrosion resistance. In standard outdoor or coastal-adjacent settings, 304 SS performs well with minimal maintenance.

These eye bolts use the standard metric coarse thread M18 × 2.5 pitch, which is compatible with any standard M18 hex nut, flange nut, or flat washer following ISO metric thread specifications. They are not compatible with M16 or M20 hardware. If you are threading into a tapped hole, ensure the hole is tapped to M18 × 2.5.

Yes — M18 eye bolts are a common and reliable anchor point for catenary wire systems, outdoor string lights, rope spans, and cable runs. The closed ring eye allows you to pass wire directly through the loop or attach a carabiner or thimble. Ensure the mounting surface (timber beam, concrete anchor, or steel post) is rated for the combined weight of the wire and any suspended load.

The 70mm full-thread variant has threads running the entire shank length, maximizing thread engagement — ideal for tapped holes or applications requiring deep nut seating with no unthreaded shank. Partial-thread variants (b=70mm or b=80mm) have an unthreaded shank section near the eye, which provides a cleaner bearing surface when passing through a clearance hole in wood or metal, and generally offers better shear resistance at the hole interface.

Using a flat washer under the nut is generally recommended to distribute the clamping load over a larger surface area, especially in softer materials like wood, composite panels, or thin sheet metal. This helps prevent the nut from pulling into the material under sustained load. For installation: drill a clearance hole (typically 19–20mm for M18), insert the bolt, add washer and nut, and torque to the appropriate specification for your application. Apply thread-locking compound if vibration is a concern.