Cousins is a respected supplier to the horological trade, they should be able to advise.

The spec says it has similar composition to CZ120 and is a free cutting leaded brass. I would have no qualms about using it for clock plates or wheels.

regards Martin

From the alloy contents, H62 is very similar to CZ108.

I've often wondered why clock-making books always recommend CZ120 rather than, say, CZ121. They're both free-machining brasses, but CZ121 is more so. I see CZ120 is described as 'Engraving Brass' and it has less Lead in it. I think this would make it a shade harder than CZ121, allowing it to take and hold sharper engraving cuts, useful because engraving is common on clocks! CZ120 is also described as 'decorative'

If no engraving is needed, I guess CZ121 would be a good substitute, though slightly softer, which might wear faster.

H62 is an ordinary brass, no lead in it, not as free-machining as CZ120, but stronger and more ductile. It can be pressed, but I don't think that helps clockmakers. One website says its good for: Coppersmithing work for chains, eyelets fasteners, hinges, kicking plates, locks, fingerplates and wire brushes; various cold presswork products including instrument covers and containers; blanked articles such as instrument plates and wheels; cold headed items including pins, rivets and screws, springs, radiator tanks and reflectors. Cheaper and OK for clocks but not as pretty as CZ120, or as easy to work, or suitable for engraving.

As a beginner I'd go for the recommended metal rather than risk an unexplained substitute. Easier to learn with the 'right' material rather than have to cope with a difficult one as well.

Dave