Sharps Secondary Martial Pistol

I came across an old Sharps pistol w/ all matching nos. but w/ a broken lever spring. This spring holds the lever in place which in turn actuates the dropping block. I was determined to make this spring & I took a pc of ohgs approx 3/16 x 1/4 x 1.1/2 & roughed out what I could. The finished spring looked like a miniature teaspoon. I soft soldered the bottom to a pc of crs & proceded to mill the flat spring to the required thickness of .030 x 1.1/4. From there it was easy as I melted the solder & removed the spring. Finishing up w/ appropriate needle files & riflers, the finished item was a honey. I then heat blued it & attached it to the underside w/ the orig screw which was on the gun. Have any of you gun people ever encountered a similar situation w/ a broken flat spring on an antique gun?

I hope you hardened the steel before you heated it to blue. I am not sure what you mean by ohgs. Is that pre hardened,such as pre hardened 4140? If so,the prehardened 4140 is already too soft to make a good spring. it is in the Rc. 30's range. A spring should be 52 Rc.. If you heated that stuff blue,you fully annealed it.

Sharps pistol

OHGS oil hardening gage stock. This material has some inherent toughness even w/o hardening. It worked fine as the flexing was only about 3/32 & the spring remained strong

Made a few springs, and if it works and does not take a set (lose it spring force) leave it alone.

In general, all polish marks, scratches etc should be removed or paralell to the flexing of a beam type spring.


The comments about springs having to be in the RC50+ range displays a aommon misconsception that hardeing changes a piece of steels elasticity. It does not change the stiffness. It does adjust the yield strength.

The spring has the same spring rate until you reach its yield point, then it takes a set or breaks if the yield and ultimate strenght are too close together (very high strength, hard steel)

The reason springs are made from very hard, strong steels is that we ask so much of them. The amount of movement (strain) is proportional to the stress in the steel. We want to keep the ratio of the maximum working stress well below the tensile strengh of the steel (half or less). Otherwise fatigue can be a problem. Of course, as strenght increases, so does hardness. The yield strength and ultimate strength get close together as well. This is why heat treated parts get brittle.

With an old design like a sharps, its unlikely the springs are made from anything exotic. It simply was not available. Alloy composition, temperature control and other important factors were difficult to regulate. All of this forced the designers to keep the stresses low. Our modern steels like O1 should easily outperform the steels available 130 years ago. A more modern design is quite likely to push the envelope. We have better control of the steel and better ability to model the stress.

Spring steel is what common saws were,and still are made from for hundreds of years. They started rolling it in about 1765 in London. The spring needs to be about 52 RC,or it may lose its set,and not function after it is flexed a number of times. His spring only requires a small amount of flexing,so perhaps it will last a while soft. My post is not a misconception if you want a decent spring that will not lose its set. There is nothing spohisticated about simple 1070,1085,or 1095 steel. The last 2 numbers refer to the carbon content: .70,.85,.95. A spring of 01 actually has about 1.02 % carbon,which is really a bit too much,plus it has other alloys you don't need for a spring. It is safer to use the simple steels I mentioned above,if you are going to harden and temper the spring,and it has to flex a lot.