Patch box spring catch

[ed lundquist]

Thanks in advance for your help. Today I sawed and filed a latch spring for a smr as per the tutorial by Ken G. Heated to red, guenched in oil, covered in oil and burned oil away. No spring only bend. New to this metal stuff, could it be the wrong steel or did I miss something in the instructions? thanks again.

[Scota4570]

Spring steel?
Heated to orange-red in a lighted room, quenched in oil.
Test it. A file would not cut it when hard?...good.

Draw at 750* in your bullet casting pot.  Use a thermometer.  Hold under the lead surface or 10 minuets or more with a piece of wire.  Air cool. You have a spring. 

I don't have the experience to burn off oil to achieve 725-to 775 ish degrees.  Different oils behave differently.  I don't have the patience to to make and break springs on the on the last step. 

Work around...Depending on the spring you need you could possibly make it from clock spring and skip the heat treat steps.  Look of such spring recoil starters of small gasoline engines. 

[bgf]

What type of steel?  It sounds like low carbon mild steel, which won't harden and thus can't be drawn back to springy.  The process is not real finicky with the right kind of steel.  1075 would be ideal, but the straps that secures stuff to pallets work fine also, whatever steel that is...I've got a lot of that so I use it.

[smylee grouch]

Some people have used old hack saw blades with success.

[ed lundquist]

Failed to mention this was from a cut nail. Not all nails are created equal. I will attempt this with the lead and if that doesn't work, on to plan B.

[flinchrocket]

In the tutorial he used a masonry nail (High carbon) for the lid catch spring.

[rich pierce]

A cut nail is not going to work as a spring.

[M. E. Pering]

Ed...  You need to get some real spring steel if you are serious about making springs.  I use 1095 often, but 1075 seems to be the favored composition.  The last 2 digits indicate the amount of carbon in the steel. and either of these steels are considered fairly high carbon.  You must understand, that some carbon burns out in the process, so most spring, once made have less than 0.95 or 0.75%. 

If you are trying to make a thin spring, some have suggested a hacksaw blade, and I agree... This makes good spring steel.  However, if you are trying to make anything heavier, then buy some spring steel.  I have used, to great success, leaf springs from the salvage yard.  But this does require you have an ability to forge, and many can't do that.  But if you do have that ability, then try and keep the orientation in the same direction if possible.  Your best bet though is to spring for some actual spring steel  ( I couldn't help myself ).

M. E. Pering

[Curtis]

You can try to caseharden the "spring" you made from a cut nail.  I may make it springy enough for the task.  A high carbon spring steel would be the preferred method....

Curtis

[Dennis Glazener]

Not sure what kind of latch spring you are making but I have used a regular 20 penny nail for a sliding patch box spring. I did not harden either one and both worked fine. I assume it got work hardened which may have given it enough spring to work properly.
Dennis

[PPatch]

Ken does use masonry cut nails for his latches - you can buy them at the big box store. You have to anneal them before any shaping can occur. Take them up to red heat then bury them deep in warm sand for as long as it takes for them to cool completely.

Cut, file to shape. Use a chisel or graver to cut some small spikes on the lower part of the shank.

Heat to red heat again and quench in oil (I've given up on the sardine can trick, results vary too much). I draw the temper with a torch, like so...



While you're at it anneal part of a hacksaw blade to use as your internal lid spring. you can shape it along with the nail.



Oh, and be very careful with positioning the latch nail prior to hammering it in since it isn't coming back out.

dave

[bama]

I have used cut nails to make the catch spring. You have to draw it out pretty thin and with the part that drives into the wood fairly pointed so you can drive it into the bottom of the box cavity. I usually polish back to bright after the forging process and then do a heat blue to temper it a little. I have always been able to get a catch spring that will flex enough to do the job. I have had a spring like this on several rifles and have yet had one to fail. Now if it is an actual spring when I get through I could not tell you but it will do the job.

I use old hack saw blades for the lid springs. I grind to shape, then heat to a bright red orange , quench in 10w30, let cool and polish back to bright, then I heat to a temper blue, I quench in the oil again but this time it is to stop the heat so it will not soften to much, if it goes to a grey it will be to soft. I will have to admit that if you don't do this right the spring will break after a few cycles or bend. Most of the time they come out good and will work flawlessly for a long time.

[bama]

PPatch that is a very nice looking rifle

[PPatch]

PPatch that is a very nice looking rifle

Thank you Jim. I will post it when it is finished.

dave

[ed lundquist]

Thank you all. I am better prepared for my next attempt. In the meanwhile I took a large paper clip, not the wire kind the one with the wire squeezers, and fashioned both latch and spring from it. Need to adjust the opener spring as it really throws the lid open, got too late to finish last nite. Pops like a mousetrap!