Small Springs

[Scota4570]

Been having problems making sear springs.  I have been trying to use blue spring stock from old victrolas.  It is not real thin, thicker than pallet banding, about like a band saw-hack saw blade.  Thicker than a hand powered hacks saw.   I aneal, make the spring, heat orange-quench in water, draw in a lead bath using a thermometer.  So far I am batting 0.0%. They break at the V-bend.   

Do I need to make them of thicker stock?  Maybe the thin-ish material is burned up in the heat red then quench stage?  Should I do that with less direct heat?  I am using a propane torch.  Anyone have any success with clock spring in general? I've been eyeballing large binder clips.  Are they useful? 

[D. Taylor Sapergia]

First, when you bend the spring to make the elbow, try to avoid thinning the metal in the bend to less that that of the working leaf of the spring.  In other words, thin the working leaf so that the action is in the lower leaf - not the elbow.
Second, polish the newly formed spring and heat to red - not orange.  Quench in oil - not water.  Re-polish and heat to a uniform blue - lead or oil bath is fine, though I often just use the soft heat at the furthest extremity of a propane flame.  Take you time.  Should be good to go.

[rich pierce]

Yes. Also I'm sure you'll remember to check that the spring did get hard after the quench before tempering. Taylor brings up a great point about bending flat stock. It gets thinner in the bend. Also i like to bend any spring around a form. Could be as simple as an old large screwdriver ground to a radius or for a mainspring an old ground cold chisel. This keeps me from getting a scrunchy V in the bend. Last but not least you get what you get using recycled steel. I know cause I often use it!

[okieboy]

 I really think, if you want to be successful, that the first thing to do is to go to McMaster-Carr and order some 1074/1075 spring steel stock so that you are starting with new material that you know exactly what it is and can look up exactly how it is properly hardened and spring tempered. The price, which is not high to begin with, will be justified many times over by the frustration of guessing how to heat treat an unknown material, made by unknown process, with unknown quality control.

[Scota4570]

Buying spring stock is ideal.  It is not inexpensive. An 8 x 12" sheet of the likely same material, I have,  is 20-bucks.   Each wound up roll that I have is bigger than that.  I have a bunch of them. 

http://www.mcmaster.com/#standard-spring-steel-sheets/=xr5ehb

If the material can be of use I want to use it.  The springs are 100 years old.  I bet they are some simple steel alloy.  Trial and error may produce something useful.  If not I have a bucket of junk. That is OK too, it was free.  I was hoping somebody had experience with "clock spring" and could give some tips. 

[jerrywh]

 What temperature do you draw the spring too.  You should hold it at 725 or 750 for about 7 or 8 minutes.  Also do not heat too hot when forming. Any red heat is hot enough. Do not bend at less than a red heat.

[Mark Elliott]

Modern type (spring wrapped around screw)Sear springs are super easy.   I use 1/32" stock (~1"x12") that I buy either from Brownells (1085) or Admiral steel (1095).  Admiral steel is cheaper, sometimes a lot cheaper.  You can cut that with aviation snips and then just file the edge smooth.  Then all you got to do is bend it to shape while a cherry red.   I use my little metal bending pliers (jewelers pliers) to do that.   I then just heat to salmon and quench in light oil (usually 20W motor oil).   Make sure it is hard.   Then I heat it to 700F in my heat treat oven.   I just bring to temp, hold 30 mintues and remove to air cool. 

If you don't have a heat treat oven, you can use an varlable temp electric lead pot.   Just adjust the temp until the lead completely melts.   Usually that is around 700, maybe a little less.   Set the spring on top for 20-30 mintues.  Then remove and let cool.  This method has worked for me lots of times.

Now,  if you want a traditional type sear spring with the little tab for the screw,  that will have to be forged out of a piece of 1/8" 1095.   I  stock 1/8" and 1/32" 1095, all from Admiral steel because they are the least expensive and will sell very small quantities.   You would just need to cut off (with a hacksaw) a piece 1/8"x1/8" long enough not to burn your fingers by getting them too close to the flame.   

I use my Oxy-Propane torch with the rosebud tip for little springs like this.   It is too easy to burn up something that small in the forge.   Of course, you can use a MAPP torch for something this small.   

[LRB]

Jerry's advise is dead on, and clock springs are almost always 1095 steel, as are most of the springy type packing bands, or at least they used to be.

[Bob Roller]

Jerry's advise is dead on, and clock springs are almost always 1095 steel, as are most of the springy type packing bands, or at least they used to be.

I have tried clock springs as well as other sheet metal springs and had no satisfactory outcome.
The ones I have made for years are vastly different from the commercial production springs but
then my approach to lock making differs as well.

Bob Roller

[Scota4570]

I had success with this.  I cut it with tin snips.  I used a propane torch to bring it to dull red.  Cool.  File.  Bend with jewelers pliers, while red hot.  All bends got a radius. While hot but not glowing I tossed it in water, mostly to no burn my fingers. 

The spring works fine. IT seems the key is not not get too crazy with the torch.  I used minimal heat.   

Next I'll try the real heat treat.

Thanks,

Scot   

[D. Taylor Sapergia]

I've used worn out hack saw blades for years to make kick springs for patch boxes.  They work great and have never had one break.  But having proper spring steel stock on hand is definitely more confidence building.

[Acer Saccharum]

Doesn't Brownell's sell an annealed spring steel assortment? I have some from them, and it's buttery soft.

[jerrywh]

 You may not believe this but I have not had a spring fail after heat treating for over 15 years. I often wonder why so many people have trouble. Any spring steel from 1075 to 01 works fine for me but I prefer 1095. I quench in water with about 1/8" of transmission oil on top. If the spring is hard enough you can see grey spots on it and a file will skate on it. I then temper to 725° to 750° for 20 minutes with mainsprings and about 12 minutes for smaller ones. Let cool naturally. Do not quench after tempering until the spring reaches a temp cool enough to pick up with your hand.
   

[Mark Elliott]

Doesn't Brownell's sell an annealed spring steel assortment? I have some from them, and it's buttery soft.

They do sell plastic tubes with assorted sizes.  You can get a tube of flats or a tube of rounds.   I have not had good luck with these.   I have had trouble with springs made with this material breaking, and I am not sure why.   I have never had this problem with any other material I have used to make springs.   I have been making springs for going on 40 years and have had very few failures.

The 1" strips of 1085 (in different thicknesses) from Brownell's worked much better.    However,  you can buy 1095 in most any form or size you like from Admiral Steel at half the price of Brownell's.   I do believe I ordered my last batch of 1/32" (1" strips) from Brownells because Admiral didn't have that thickness at the time. These days,  I usually buy my 1095 from Admiral and everything else (brass, 1018, 12L14, drill rod....) from Online Metals.   

Online Metals will cut stuff to the exact size I want for just $1 a cut.    It really saves me a lot of work and hacksaw blades.   I get material ready to forge or machine.   Every time I place an order, I worry that Online Metals will tell me they won't cut any more for me.  The local metal supplier won't even consider selling less than 12' unless they happen to have some scrap laying around.   I can pick up drill rod at one of the local hardware stores, but Online Metals has five packs of 36" drill rod packaged in a plastic bag for about the price of one at the hardware store.   You just have to pay for shipping, which is often more than the metal you are buying.   

[FDR]

TOW has a nice inexpensive booklet on building springs. I refer to mine often.

Fred

[P.W.Berkuta]

I had success with this.  I cut it with tin snips.  I used a propane torch to bring it to dull red.  Cool.  File.  Bend with jewelers pliers, while red hot.  All bends got a radius. While hot but not glowing I tossed it in water, mostly to no burn my fingers. 

The spring works fine. IT seems the key is not not get too crazy with the torch.  I used minimal heat.   

Next I'll try the real heat treat.

Thanks,

Scot   

I just made a patchbox kicker spring out of 1075 that started out as 1/8" thick X 1/4" wide and 1-1/2" long. I grabbed it with a small vise-grip pliers - heated it up and pounded it with a 8-oz ball peen hammer until it was 0.020" thick. I then trimmed it to length & width and bent it to shape. I placed 3 fire bricks in a "C" shape as a make-shift flame barrier and heated the part to salmon red color. The thin spring wants to cool down FAST so you have to get it into the quench quickly - I used ATF which was at hand. The problem was with the tempering of the thin spring - I first used the "melted  lead" trick - the spring was soft not a spring -- next I re-harded the part and used the "burning oil" trick, the spring was still soft then I again re-harded the part and this time I polished the spring and "played" the flame over & around the part for a bout 30 seconds and this time I got a spring --- solution was "DON'T USE A LOT of HEAT on a thin spring to temper it - they get HOT FAST

[jerrywh]

  About 50 years ago I made springs for gunsmiths and sold them by the dozen. At that time I was having trouble with some steel. The problem turned out to be flaws in the steel.  These flaws are invisible unless the steel is red hot. An engineer taught me how to find them. Before you make a spring from a piece of steel heat it red hot and look for any bright lines in the steel. The flaws will show up as a line in the steel that is much brighter than the rest of the piece.
 If you see these defects junk it.  These are caused by rolling flaws when the steel is rolled out. Those type of flaws do not effect some type of springs such as flat coil springs that are used in some Auto applications so they are not considered critical for most applications but for our purposes they are terrible. Most all the spring steel in those days was produced to the standards of the Auto industry and may still be today as they use the most steel.

[Mark Elliott]

Jerry,   That was very useful information.   Thanks