Thread: Banebots 42mm gearbox: Recommendations for use
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Unread 30-01-2007, 13:38
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Re: Banebots 42mm gearbox: Recommendations for use
Here are the results of some testing done at a materials lab today:

Before Heat Treatment:
HRC 21.4, 23.7, 23.8 - right on target with Dr. Joe's tests

Annealed at 900C for 15 minutes, then quenched in water:
HRC 59.9, 59.8

According to the lab technical instructor, who knows more about materials than I could ever imagine, this is tool steel. It comes annealed, which makes it easy to machine, but can be hardened quite a bit with heat treatment. (My chart says that as-quenched, the tensile stength has gone from ~119 ksi to almost 300 ksi.)

I have the carrier tempering now at 300C for a half hour. This will bring the hardness down a bit, but make it more resistant to fracture. Very good news for the 42mm gearboxes. I'm not sure how it applies to the 56mm, but hopefully those can be hardened too.
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Last edited by ZZII 527 : 30-01-2007 at 13:43.