Galvanised Square Twisted Nails 30 x 3.75mm 2.5kg are robust fasteners sold in a larger quantity for construction projects where a very strong and secure joint is essential. They have a 30mm length and a substantial 3.75mm shank diameter. The signature square twisted shank mechanically grips wood fibres, significantly increasing their withdrawal resistance compared to standard nails. These nails are primarily used for attaching metalwork such as joist hangers, restraint straps, and nail plates to timber frames, and are sometimes used for cladding or roofing felt. The galvanised coating provides medium-duty rust protection, making them suitable for interior use or exterior applications in occasionally damp, rural, and sheltered environments (conforming to Eurocode 5 and Service Class 2). A 2.5kg pack contains an approximate quantity of 890 to 1,000 nails, based on a typical estimate of 357 to 400 nails per 1kg.