Davis Triggers

[54Bucks]

 Has anyone recently reshaped the triggers of a Davis assembly? Are they difficult to heat and re-shape? I assume one needs to disassemble before heating and shaping the trigger/s??? Then anneal before re-assembly? I'de like to change the front trigger on a future build so it doesn't scream out....."yes I'm a stock Davis assembly!"

[D. Taylor Sapergia]

Davistriggers are very hard.  If you try to bend them without red heat, they'll snap.  To file them, you have to anneal the steel.  Then aftern polishing, re-harden, and temper.

[Dphariss]

I used a Davis on the current project and may rework the front trigger. I already reworked the internal on the rear trigger and may well rework the external part of the front trigger. Like Taylor said they are hard so they must be heated to dull red and allowed to cool.

Dan

[Ken G]

Taylor is right on the money.  I broke 3 rear triggers before I learned they had to be RED hot to bend.  Anneal before trying to file.  Reharden and temper before use.  

You building a TN?  

[Lucky R A]

       I have found that after heating and cooling they are still hard and brittle.  It is my understanding that Davis uses some type of "air hardening" steel.  Apparently the only way to make them malleable is a very slow cooling process.  We kicked this around before, I will let someone with book learning comment..... I do know that i have had them break after heating, reforming and then just allowing them to cool normally.

[Ken G]

I've never been able to bend them, even after annealing.  They just don't bend unless they are red hot.   
Ken

[Dphariss]

I stretched the Davis rear trigger but did it by heat and hammer.
In annealing unknown alloys its best to not exceed dull red if that high. Sometimes heating to the grey color just before red will allow a part to be filed.
Getting them too hot they could air harden depending on the alloy.
I ran into this when I was a kid making a knife from a wagon seat spring. Finally heated it in the forge and just let it cool with the fire. Once cool it was soft.

Dan

[Ken G]

Maybe that's why I had such bad luck bending them.  I was getting them too hot.  I would bury them in sand to let cool but it didn't seem to matter.  Thanks for the info. 
The entire issue went away when brother Bookie put me on the path of making my own triggers. 
Cheers,
Ken

[bgf]

I believe they are air-hardening steel, and I didn't have much (any) luck annealing them, so I got some L&R's which fit the same basic space and were quite easy to work with using my limited skill set.  I'll use the Davis one later (I have a build planned where their looks won't hurt anything).  Maybe I'll try Dan's tip and modify slightly just to see if I can conquer them -- likely I was heating the Davis' too high.  On the plus side, as hard as they are, wear should not be any problem, but, at the time, knowing only a bit about them I feared they would also be brittle when that hard after what I thought was proper treatment:).  As they are air hardening, I wonder if it isn't luck of the draw in terms of environmental conditions what luck people have with them; I also assume an oil quench for hardening would make them very brittle, perhaps beyond the capability of usual tempering methods. 

[David Veith]

I just talk with Tim. They are using 8620 Steel It is not a air harding steel.
David

[jim meili]

Just went through the exercise of trying to bend a Davis rear trigger. Put it in the vice and tried to close it up a bit and it was just like a spring. Put some heat on it and it finally gave in and started to bend. The tip of the catch didn't get enough heat to effect the temper. Very risky operation. If they use 8620 steel, that is bearing race steel and can be annealed. One good barrel maker uses it for his product and certainly in an annealed state. Barrels made from it will last forever.
Jim

[D. Taylor Sapergia]

Bill Shipman has done some wonderful filing on Davis triggers...Bill?
 I had a lot of trouble once with a tumbler, new as cast, but I could not drill it for the hammer screw.  After ruining several good drills, and asking questions of knowledgeable friends Acer and Cody, I built a little fire in my yard of birch, and got a good bed of coals.  Then I used my portable oxy/act. torch to bring the tumbler to red heat, and dropped it into the fire.  Three hours later, the fire was out, and I pulled the part from the ashes.  It was dead soft and cut like mild steel.
I suspect that Davis triggers would do the same.

[keweenaw]

One doesn't get 8620 as hard and unmalleable as Davis triggers by just heating and quenching it.  I suspect that the triggers are carburized (case hardened) after they're brought to final dimension.  One needs to know not only what type of steel something is made from but also how it was heat treated.

Tom

[Acer Saccharum]

Yeah, 8620 is a medium carbon steel, as I understand it. It casehardens well, leaving a softer core. On small parts, it might case right thru the whole part.

[Dphariss]

One doesn't get 8620 as hard and unmalleable as Davis triggers by just heating and quenching it.  I suspect that the triggers are carburized (case hardened) after they're brought to final dimension.  One needs to know not only what type of steel something is made from but also how it was heat treated.

Tom

I seriously doubt they are 8620. There is no reason to make through hardened parts from 8620.
But? Through hardening would just add time and cost in making the part.

Dan

[Rootsy]

Not so long ago I witnessed a couple of brainiacs trying to straighten a 1 1/2 thick x 8 inch wide x 36 inch long, improperly heat treated (via carburizing) part made of 8620.  Had curved like a banana during heat treatment and had been through hardened.  They put it in a 25 ton press and proceeded to make it a banana in the opposite direction.  When it abruptly fractured things got REALLY interesting for a few moments as people standing around scattered like mice and 2 pieces of 8620 landed on the floor... 100 man hours of machining + material and outside processing, right down the tube...