How I forged a new spring for my leg vise

[Timothy Miller]

I got this vise for 25 bucks it was missing the spring. It is an mid 19 century William foster vise it has a crown stamped on one leg. It is rather crudely made the front jaw is not centered on the leg I think this vise would have been sold as second quality. Everything on it seems to be forged from wrought iron and kind of rough and ready. Though the screw and box are really well made, go figure. Because of this I decided to forge the spring from wrought iron. It worked just fine. Proves you don't need anything special to make a leg vise spring from. This is not the only way to do it or even the way it was done as far as I know, but I used existing springs on other vises I have as a guide. I also looked to the quality of the original workmanship to guide me. You may notice some fine cracks or shuts in the wrought iron but as far as I'm concerned this is right on because the original vise is full of them. I tried to make it look as original as possible.

1. I measured from the top where the clip sits often times indicated by a incised line on the back leg to the top edge of the pivot plates on the front leg. I came up with about 11".
2. I forged out some scrap wrought iron to about 3/16 x 1-1/4" to the correct length. Most wrought iron needs to be forged at a near welding heat or it may split.
3. One one end I forged a short 90 degree bend about the thickness of the retaining clip sometimes called the staple. This was accomplished by bending it over the edge of the anvil and upsetting it to a square corner at a high heat.
4. The bottom of the spring is peened out with a cross peen hammer over the inside edge of the anvil. I took about a 3/4" bite. Sometimes the material is folded back on itself and welded. This allows for additional material to form the spread and helps eliminates splitting a the end of the bar when using wrought iron.
5. Close up of the shape smoothed and ready to be formed to the leg.
6. I bent the paddle shape into a shallow U by hammering into the anvil step. I then placed it upon the leg and hammed it to shape using the leg as a form. I also tapered the spring a bit to match the taper of the leg. This also gave me some additional length that will be lost in the bend.
7. The spring was bent over the horn it took 2 or 3 tries to get the shape right. I found bending cold worked better and that I needed to over bend it by about 25-30% because the spring unbent a bit AKA it took a set.
8. New spring in place.

[Pug}{maN]

nice , you make the mount ? i have a spring but no mount... i could use angle iron and a u bolt , but id like to make something that looks nicer..

[Timothy Miller]

About 2 years ago I forged a mount I did not take photos. I have a really nice 6" vise with no mount or spring when I get around to it fixing it I will post process photos. It may take me a few months though.

[r smith]

clinton made a mount that he shared with us a while ago.

[pkrankow]

Very clear Tim. Thank you.

Pug, here's a thread with the information you need. More than one way to mount a vise is listed.


Phil

[BackyardBlacksmithin]

I have a vise I just bought that is overall in great shape, but the spring only opens the vise to about a half inch then it stops. I want to re-heat the spring and re adjust it to open the vise farther but will I need to heat treat the spring when I'm done? And if so how far do I draw the temper down to?

[ThomasPowers]

If it's made from mild steel: no  If it's made from High carbon steel: yes

[BackyardBlacksmithin]

hmm... I guess i need to figure out what type of steel the spring thats in it is.

[Walnut Square Iron]

Good post. I pinched my hand a few weeks ago since mine does not have a spring.  This may be the kick in the pants to get one done.  

[MLMartin]

I have made a few new springs for leg vices. I have always used old automobile leaf springs. I forge to shape then I normalize once. I do not bother with hardening or tempering. There is still plenty of "spring" to the steel without heat treatment for this application. The spring only needs to push on the front beam for about 1". When the bottom of the beam has moved 1" the top of the jaw has normally opened 4 to 6". More than enough for normal use.

 

A leaf spring for a car needs proper hardening and tempering because it undergoes high stress. A leg vise spring undergoes very very little stress and a very little amount of travel. 

 

Look at Mr Millers new spring. Its wrought Iron! And it works fine. And I do not think he heat treated it

[BackyardBlacksmithin]

Ok so I think I will just try to reshape it cold and if that doesn't work like I want I will just heat it and reshape it and normalize it and see how that does. Thanks for the help

[Timothy Miller]

I retrospect I would use something with more spring than wrought iron the wrought iron works but it needs to be reset from time to time. I may case harden the wrought iron spring next time I make one I'm sure that would do the trick. Water quenched hot rolled mild steel AKA A36 is a very good option.  5160 the steel commonly used to make leaf springs is a bit much for this job it tends to make the vise too stiff.

[MLMartin]

I have had a vice with a factory spring installed that was way to strong and You are right about a overly stiff spring being to much. I just use old leaf springs because they are free and close to size. I make my leg vice springs very thin. My 100lb 6 1/2" vise has a spring that starts about 5/16 thick 1 3/4" wide and tappers to about 5/16 by 1" at the bottom. You can easily spin the handle closed 2 revolutions with just a few fingers. I often actually close the handle with my knee while I am holding large work, then I will finish tightening the screw by hand when I can let go of the item.

 

Probably to good way to judge if your spring is to tight is to see if you can easily close the jaws together without the screw. A person should be able to push the front jaw closed with one hand while the screw is extended. The spring ONLY needs enough force to open the front jaw nothing more.

[Chinobi]

thanks for the rundown Tim, ill need to keep this in mind if I get fed up enough with the spring on my vice.  the previous owner had replaced it and its waaay too strong =/

[Dan C]

For a 4" vise what size diameter coil spring would you start with?  I have some 1/2" that I've started to flatten out but it seems like it's going to be either too thin or not wide enough.  Then again I may just proceed and see how it does.

[ThomasPowers]

There is no set width  you could leave the stock round and just flatten for the top section and split and bend out the bottom section.

[arkie]

There is no set width  you could leave the stock round and just flatten for the top section and split and bend out the bottom section.

 

Thomas, that's a great idea.  Why is it that we seem to have this burning need (pun intended) to make round things square and square things round?  I've got some big truck coil springs and might use them for my next vise spring.  Your observation would make for less work and maybe a better vise spring.

[ThomasPowers]

Way too heavy stock!  You want the minimum required to open the vise so you can close it easily even using your knee to spin the handle.  I've used 1/8" thick mild steel before for a small vise.  Better to clean and oil the pivot area than to make a heavier spring.

[arkie]

These truck springs are only 1/2" to 3/4" round (don't recall the actual size, would have to measure...raining outside).  Been using pieces for punches and drifts.

[ThomasPowers]

Do what you will; just don't come back complaining how difficult it is to close your vise quickly when you are working hot steel

[arkie]

Not complaining (yet  :) ).  Just mentioning the size I might be working with.  Will certainly heed your advice, thanks.

[Deivi]

If it's made from mild steel: no  If it's made from High carbon steel: yes

Oi! Ladies and Gents!

newB here.

My  concern is about several leaf spring i found on a pile dive. How does one find out what kind of steel it is. I believe they came from trucks but I really have no way of knowing.

I have 2 leg vises with missing parts the main one is the spring. Also from what i gathered on this topic(PLEASE CORRECT ME IF I AM WRONG) I should try cold forming the spring and if it doesn't work then air cool temper? 

thank you in advanced  

from Oakland 

Deivi

[VaughnT]

Deivi, there's no way to tell what alloy your 'found' springs are made from.  They'll be a high-carbon steel, but that's all you can assume unless you want to send a sample off for testing.

 

Springs on leg vises don't need to be high-carbon.  Mild steel works fine.  You can cold-bend mild steel without any worries in this application because you aren't bending far.  No need for tempering anything.

[Deivi]

VaughnT 

Thank you this information helped me alot!

Now i can get to work!

[ThomasPowers]

Vehicle springs are generally on the cusp of the medium carbon/high carbon division and generally made of alloys like 5160 or 9260; *BUT* they can be made of anything the manufacturer thinks will work the cheapest! (I once ran across a low carbon strain hardened leaf spring---couldn't be quench hardened!---of course that's 1 in 30+ years of smithing....)

So TEST IT FIRST if you need the qualities of higher carbon steels. For a post vise you don't need a HC steel.

DEIVE; trying to work it cold and failing usually has the failure mode of having several pieces where you once had one. Sometimes blood and stitches are involved and/or replacing your face shield and safety glasses---not wearing them? Just run out and get a replacement eye---we'll wait!

Just normalize the spring; it will be workable if HC and won't be much different if LC, (normalization will allow for dislocation climb if it's work hardened)