Hardenable free cutting steel for clock pinions

[Roderick JenkinsParticipant @roderickjenkins93242]

Does anybody have any experience of using EN8M (212M36, 1140) as an alternative to the no longer available free-cutting silver steel for making pinions (or, indeed, anything else)?

Cheers,

Rod

[Roderick JenkinsParticipant @roderickjenkins93242]

[roy entwistleParticipant @royentwistle24699]

Is free cutting silver steel no longer available ?

Roy

[Peter BellParticipant @peterbell11509]

I've used EN24T previously with great success using Thornton cutters and left it in it's natural state after polishing.

Peter

[lfoggyParticipant @lfoggy]

I've used silver steel, EN8 and EN24 for making clock pinions. The EN24 is by far the best. Cuts quite easily with a Thornton HSS cutter with flood coolant leaving a very good finish that requires minimal polishing. The EN24t is already hardened and tempered and no further heat treatment is required. The silver steel cuts less well and gives a less good finish and needs hardening but is OK. The EN8 can't really be hardened in the average home workshop.

If you don't have J Malcolm Wild's book 'Wheel and Pinion Cutting in Horology' I would recommend this….

Edited By lfoggy on 13/08/2023 20:44:38

Edited By lfoggy on 13/08/2023 20:45:35

[Roderick JenkinsParticipant @roderickjenkins93242]

Thanks for the comments. My tentative plan is to make a pinion cutter from silver steel backed off with my Eureka tool. My fear is that EN24T may be a bit much for the carbon steel cutter. I note Ifoggy's comments about hardening EN8 and have referred back to a previous thread. I do have a small electric furnace and made Lammas' hardness tester so maybe some experimentation is called for . Or perhaps I'll stick to lantern pinions.

The recent talk here on simple clocks has led me down a rabbit hole and piqued my interest for the next project.

Rod

[Mark RandParticipant @markrand96270]

Carbon steel will cut EN24T quite well. Just keep the speed well down.

[Nigel McBurney 1Participant @nigelmcburney1]

I found that en8 does not harden ,ie heat to red heat and water quench,it does get tougher and it does shrink.Modern supplies of silver steel are variable regarding machinability and accuracy on diameter,the old Stubbs silver steel was far more reliable.

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