Sizing small compression spring

[lhfarm]

Cleaning up a hydraulic control valve (another thread) and need to replace the small springs shown in the picture. They are 1/4" x 1" and I believe 1/4" by 1 1/4". They are slightly bent from being in use for over 60 years. I've tried local hardware stores, but no luck. Searching the net, I believe I need a third measurement and maybe a fourth. I believe I need the size of the wire and maybe the number of turns per inch. Is there a standard sizing method for small compression springs? What would you enter in a search string? I've tried dia x length x gauge x turns (guessing on the wire size) and haven't found anything.

The other question is where I might find a good selection of springs. Tried the box stores and one hardware. The hardware had a 1/4" x 1" but not the number of turns (not as stiff). Suggestions?

Thanks,

 

[Mace Canute]

You might try McMaster-Carr They have a good selection of compression springs.

 

[jbooth]

I would suggest Brownells's. They supply gun parts. You will need OD, Wire size, turns per inch, and length. I have a lot of gun parts and could probably fix you up if give me those measurements. Might require cutting to length. Also an old spring may have lost some of the turns per inch due to fatigue. After looking at your picture, the springs look to be about as heavy as a firing pin spring out of a center fire rifle.

http://www.brownells.com/aspx/ppc/default.aspx?mc_id=1000&srch=1&gclid=CNb0_dzBmKQCFU4K2godpxwbEw

 

[jbooth]

This might be another source.


General Purpose Firearm Springs for Repairs - Pistols, Revolvers, Rifles & Shotguns

 

[lhfarm]

Thanks for the suggestions. Not sure how to measure the wire size. I have feeler gauges, but don't know if I can make a guess from that. Any tricks or tools for measuring wire size?

 

[BXpanded]

Try Century Spring. They have a big website and you might be able to figure out what you need. If I remember, buying just 2 or so from them is really expensive. Use McMaster-Carr or MSC to find just a couple of springs.

You need length, diameter and the load required to compress the spring. Wire diameter and number of turns really don't matter if the compression load is matched. Wire diameter and number of turns are only important if the spring is nearly completely compressed as too many turns or too large wire can cause coil binding. That being said, the wire diameter can help get you in the general ball park of the catalog.

You'll need calipers to measure the wire diameter. You might get a pretty good estimate by comparing a stack of feeler gages to the wire. You can find the compression load using a ruler and a bathroom scale if it's a stiff spring, a postage scale if it's a soft one. Put the spring on the scale and read the load needed to compress the spring 1 inch. If the spring is too short to compress 1 inch, compress it 1/2 inch and double.