10 gauge, by the 25 pound box, black anodized. Approximately 59 slate hooks per pound. For repairing or installing thicker slates or ceramic tiles up to 4 inch headlap. When you need a stronger, tougher slate hook, go with stainless steel. Blunt exposed points for safety.
Stainless steel slate hooks are stronger than copper slate hooks and are recommended whenever the roof decking is hard, as on old oak roof boards, or even old yellow pine, both of which tend to bend copper slate hooks.
Slate hooks are used to install replacement slates during repairs, and for replacing slates left out during the installation of a new slate roof where the scaffolding (roof jacks) are temporarily nailed onto the roof. Some slaters use nothing but slate hooks for repair work.
They may be easier to use than the nail and bib technique for the inexperienced person, and are certainly easier than the nail and bib when working with new or especially hard slates. It's always a good idea to have some of these hooks on hand.