Tempering a tumbler/fly

[gibster]

Figured I would start a new thread for this. Tried doing a search but didn't find anything.  I hardened the tumbler and the fly for the Cochran lock that is discussed on another thread. Now I need to temper it. Since I have no idea what steel was used for the tumbler (Cochran) or the fly (Siler), I don't know what temperature to heat it to or for how long. I did a search on Google and found methods using color to determine temperature, but nothing on what temp I needed to heat it to. I would rather use an oven (kitchen) if possible set at a specific temperature instead of a color chart anyway.  That may not be possible depending on the temperature that's needed. 

[smart dog]

Hi,
Every Siler lock kit comes with tempering instructions.  Assuming you hardened the tumbler appropriately (bright orange red quenched in oil), temper the tumbler to 580-600 degrees F which is a deep blue color.  Don't just bring it to color and stop, it needs to be held at that heat for at least 15 minutes or better 30.  The fly can just be brought up to the same heat and then allowed to cool. Siler instructions recommend an hour for the tumbler, sear, and bridle. In addition, I urge you to temper the sear as well to the same temperature, that way you know both are going to be equally hard and one will not wear on the other.  I always temper sears, bridles, and tumblers together in my oven so I know they are all tempered the same.

dave 

[Bob Roller]

This is like asking how high is "up"You would have to know what steel(s) you are working with.The Cochran lock was a direct copy of the Chet Shoults Ketland of the mid 1950's.and on both of  these locks were all cast parts except for the screws.I THINK they were case hardened but the materials are today,unknown.As far as is now known.there are no internal parts available now but I know the Shoults
moulds still exist but can't say who now owns them.I think these locks were case hardened so you might try that or maybe know someone
who can do it.The Shoults locks were polished and looked like chrome plating and the fact they were made by precision casting was not known until someone who knew what they were looking at saw a lot of these parts in a specialty foundry in Northern Ohio and then it became common knowledge as to how they were made.I might still have the name of the man who had the Cochran moulds and if I fo I
will send a PM to you.
Bob Roller

[gibster]

Thanks smart dog. I appreciate your input.  I'll anneal the sear and do an oil quench on it as well so that once tempered, they will be the same hardness as you suggested.  Our kitchen oven will go to 550 degrees so that will be what I will have to go with. I don't think that I would be able to hold the temp evenly for 30 minutes with a torch.
Bob, I appreciate knowing that there aren't any internal parts available for these locks.  That would explain why I couldn't find anything online on them.  I'll keep looking in case something were to show up. You never know. A blind hog finds an acorn once in awhile.

[smart dog]

Hi Gib,
This should work.  Temper your tumbler, sear and fly in your oven at 550 for 1 hour.  Then let them cool and polish them bright.  Then heat them again with a propane torch until deep blue, remove the heat and let cool.  That should be doable in your circumstances.

dave

[gibster]

Thanks Dave.  I appreciate all your advise.  The saga continues and it may be time to cut my losses and go a different route.  I tempered the fly, sear and tumbler for an hour at 550 degrees and this morning, used a propane torch to heat until they were a deep blue after polishing them as you suggested.  Made a pin to press into the hole and redrilled for the pin on the fly.  Things were looking good until I started to assemble the lock. That's when I realized that the sear was for a left hand lock, not right hand  . I'm starting to think that this lock may not be the right lock for me.

[rich pierce]

I think I’ve got a complete one if interested. PM me.