NO Zinc Alloy
Zinc alloy can not be used to make a slingshot, mainly because its hardness is very low, and it breaks easily. The melting point of zinc alloy is not high at about 385 degrees, which makes the costs of die-casting and mold processing are very low. Almost all of zinc alloy slingshots use recycled zinc alloy and non-ferrous metal, which makes hardness is extremely low. As long as the surface is coated with metal, the appearance looks like stainless steel, but quality and safety are not guaranteed.
1.In order to pursuit minimum costs, the surface was is not polished. Instead, it is coated with metal. That makes the surface less smooth but shinier than the polished stainless steel.
2,The internal material will be exposed after surface layer was polished by a sandpaper even a rock.You will see gray color.