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Sear Material

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10 Ga.

Plainsman
Joined
Sep 18, 2022
Messages
60
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Location
Georgia
Hi everyone,
If I was going to rebuild a sear what type of steel should I use and a what hardening/tempering processes?
10Ga.
 
What do you mean by re-build? If you are going to make a replacement use a high carbon steel. I would suggest 1080, 1084. Either have plenty of carbon and either heat treat easily. You could use low carbon if you can case harden it.
 
@LRB I am planning to make a replacement seer from scratch. Thank you for your help. By heat treat do you mean harden and temper similar to a spring? Sorry haven’t made a sear before and want it to be hard but not brittle.
 
@LRB I am planning to make a replacement seer from scratch. Thank you for your help. By heat treat do you mean harden and temper similar to a spring? Sorry haven’t made a sear before and want it to be hard but not brittle.
There are great on-line resources that will lay all of this out for you.

A forum thread will never provide you with the knowledge you need.

Too many variables involved.
 
Original sears were made of wrought iron, deeply case hardened in a charcoal pack and then tempered.

It takes some practice to learn hardening and tempering unless one has a furnace with a thermostat. Sears are fairly delicate as well. I’d buy a replacement given the choice.
 
The sear is from an original side by side and I am not sure where to find a replacement part. I will try to find materials online for sear making. If anyone has done this before and has a pet metal type or process I would love to know about it. This is the same sear from a previous post. Where the sear nose is broken off. I think it might be worth making a new one because the previous owner ground the sear down out If spec in the bottom Fixing up an old 10 Gauge SxS
 
My first choice would be to try to find a replacement part - this might be a difficult thing to find. My second choice would be to make one using some annealed carbon steel of 1075 or better - and get enough of it to practice on heat treating it. The part is not hard to make it's just getting the right hardness and temper so that the nose of the sear will not chip or break off and hold up with repetitive use. Good luck ;)
 
I presume since you asked what type steel to use, that you feel confident in the process of shaping it and fitting. If so I recommend O-1 tool steel. I would not waste my time with low carbon steel. O-1 is fairly easy to file , machine and drill. And is very easy to harden. After preparing the piece to fit and work properly than harden it. If you have a hole feed a wire thru it to hold it. A propane torch is plenty for a small part. Heat to just a bright red and quench by dunking into some med. oil, 30 weight will do. It will then be full hard and britle. Then clean the part with fine sand paper or scotch brite so the metal shows bright. Then reheat very gently and feathering the torch to bring the color to gun metal blue. Just take your time and heat slowly from straw color (62rc) to blue and not anymore and quickly dunk till cool. This will give you about 54 rc and will be hard but also tough. And there you have you part. If you need a small piece of O-1 let me know the size and I probably have. O-1 is a very friendly tool steel and easy to work and harden.
 
I presume since you asked what type steel to use, that you feel confident in the process of shaping it and fitting. If so I recommend O-1 tool steel. I would not waste my time with low carbon steel. O-1 is fairly easy to file , machine and drill. And is very easy to harden. After preparing the piece to fit and work properly than harden it. If you have a hole feed a wire thru it to hold it. A propane torch is plenty for a small part. Heat to just a bright red and quench by dunking into some med. oil, 30 weight will do. It will then be full hard and britle. Then clean the part with fine sand paper or scotch brite so the metal shows bright. Then reheat very gently and feathering the torch to bring the color to gun metal blue. Just take your time and heat slowly from straw color (62rc) to blue and not anymore and quickly dunk till cool. This will give you about 54 rc and will be hard but also tough. And there you have you part. If you need a small piece of O-1 let me know the size and I probably have. O-1 is a very friendly tool steel and easy to work and harden.
you sir are correct in your statement and your colors are spot on I use allis chalmers orange rather then international red for my color identifiers
 
Look for Old broken truck spring in a scrap yard. Makes good replacement material for sears and new gun springs. Aneal, make new part and re-harden the same as others say.. When tempering leave the sear nose "Straw" and the rest blue.. O.D.
 
A custom lock maker told me to use O-1. I harden by eye in canola oil. I draw in lead with a thermometer.
Lead melts at, give or take a tad, 620°F. That is much higher than ideal for the wear resistance 01 was formulated to give. That temper would make it stronger but at the cost of wasting some of the wear resistance 01 offers. 01 was created for use in industries requiring wear resistant strong steels. After hardening put it your kitchen oven or toaster oven at 400/425°F for an hour or so. The ideal hardness/strength balance for 01 is around 60/62 Rc , give or take a point or so.
 
Lead melts at, give or take a tad, 620°F. That is much higher than ideal for the wear resistance 01 was formulated to give. That temper would make it stronger but at the cost of wasting some of the wear resistance 01 offers. 01 was created for use in industries requiring wear resistant strong steels. After hardening put it your kitchen oven or toaster oven at 400/425°F for an hour or so. The ideal hardness/strength balance for 01 is around 60/62 Rc , give or take a point or so.
I have linotype which melts at 462. I'd rather be a bit soft than have the part snap. I should have been more specific.

An alternative is to heat slowly with a propane torch away from the sear nose. As the colors move toward the sear nose stop as the straw-brown color just reaches the sear nose. It does not matter if the rest of the sear is not super hard.
 
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