An element made of steel wire with a semicircular cross-section, with an eye at the bend. It prevents elements placed on shafts, axles, mandrels or other machine elements from sliding or moving. It is threaded through a hole drilled in the element and its free and protruding ends are bent in opposite directions. Cotter pins are only used when the element being secured is not loaded with axial force or when this force is small. In such cases, a cotter pin with a washer should always be used. Cotter pins are used to secure castle nuts against self-loosening. Approximate weight of 1000 pieces - approx. 0.46 kg.