Galvanized (Zn coated).
Why don't we supply clamps with safety locking nuts? We fully understand these concerns. In reality, if the clips are used properly – and that means properly tightened, it is not possible for the nuts to spontaneously loosen. The reason is that there is always strong counter-pressure caused by elasticity of ropes. The fact is that the clips were designed by much smarter people than we without washers or locking nuts - and this applies to all types of rope grips. Also, we have never received any feedback that nuts were loosening when installed on the rope, on the other hand, losing nuts during transportation in a pack or pocket is quite common. My personal experience (OL5Y) proves that they will not loosen on the rope, if properly tightened.