On Mon, 06 May 2013 19:39:44 -0500, "Pete C."
wrote:


Ed Huntress wrote:

The next step down is flame-hardened gears. These are made from
high-carbon steel, or a quick-quenching high carbon alloy. This flame
hardening requires a fixture and a quenching system that surrounds the
gear all at once -- a spray-type or an agitated oil bath.

So spin the gear on a mandrel with just the teeth in the O/A flame until
red hot and then quench it in some carbon rich used diesel oil?

Well, I don't think so. The spray fixture I've seen, for gears maybe
16" diameter, had a cricumferential row of nozzles.

And no used oil for that, please. Quenching oil. Otherwise, you'll get
bubbles attached to the steel that leave ocal spots unhardened.

--
Ed Huntress