Thread: Leaf Spring Froe

TS that is a great idea. I have been keen on getting a hold of a froe but can't really justify the expense. Making my own as you have done - brilliant! I can't see how the location of the eye would alter its usefulness.

To be honest it is simple project and needs limited tooling - the only thing that is not simple is straightening the leaf spring. - another option I want to try is using lawn mower blades - you can get them free from lawn mower repair shops and then you weld on some steel pipe. That is another option that I want to try also - you can easily drop $250 - $350 on a brand name froe - for such a simple tool it is not worth it.

The important thing is to pick leaf springs with the eye pre centred - again automotive suspension spring repair shops give them away.

Thumbsucker

I don't see why the eye needs to be centered as you will get used to whatever you commonly use. The leaf spring being high carbon steel really would benefit by being annealed so you can straighten it. Heat it up to cherry red, then let it cool slowly. Hammer it straight using a club hammer. After this you will need to heat it up gain and quench in oil to re-harden it. Then....it should be tempered by heat to a light straw and again quenched in oil. Clean (polish really0 the blade between the hardening and tempering steps so you can see the colour more easily.

A few people have had a go at Froes and old leaf springs are a popular way of sourcing the steel. A link:

Ever Wanted a Froe Away Line? (woodworkforums.com)

Just be aware that when welding onto the leaf springs, if you go down that track, you should use low hydrogen rods on a 70V setting (ie. welder with dual voltage) or if you use a Mig welder the wire fee is high tensile anyway so compatible with high carbon steel. Ordinary GP welding rods will fail on high carbon steel.

Regards
Paul

TS, I was going to tell you about my froe but I already did in 2017 in BM's attached thread. Six years........where does the time go?
Cheers,
Geoff.

Hi All

Unbending, het treating and tempering a truck spring sounded a bit challenging, even more so after reading Paul's posts. IHB 3 asked the local steel supplier for cost of 300x50x10 bisalloy HB500. Rockwell about 51 I think. Including laser cutting quote was $28. Less cost again if there was suitable off cut, available.
(note there are several versions of wear/hard plate)

Originally Posted by MartinCH

Unbending, het treating and tempering a truck spring sounded a bit challenging,

It depends on your equipments experience and setup. For me it is easy I have a forge and I have experience forgiving and heat treating tools steel.

I also have all the hammers and tongs needed for the job - the only thing I do not have is an anvil at this moment but that will be fixed in time.

The task of forging and heating is no major challenge and the making is all part of the fun of the project.

However if you are not setup for metalwork then yes outsourcing is an option.

I do als think the the lawn mower blade is a good approach since it is cut already to the perfect shape and size and all you need to do is weld to bits together.

Horses for courses.

No issues with skill, equipment and also the ingenuity for converting leaf spring to a useful tool.

Pretty common, industrially, to use pr-eharded steel and machine into tools using carbide tooling on CNC. Rather than traditional process- machine, heat treat, and then re machine - the material is distorted from heat treating. Thought the availability of heat treated steels might not be known by all.

Had a second thought- if outsourcing the steel supplier is laser cutting because the steel is too hard for saws. So it might be reasonable to consider adding 4 holes and U bolting to thehandle - as opposed to mig welding on the a tube.

Originally Posted by thumbsucker

Today I made a froe from a piece of leaf spring steel.

• I used the angle grinder the cut off and shape the tip and grind the basic shape the froes bevel is 300m long.
• heated the froe in the forge so I could straighten the leaf spring.
• ground the two bevels one at 15mm wide and one at 12mm

I tested the froe and it worked a treat.

Then I realised that in all the excitement of making that the eye was not inline with blade. I do not have a proper anvil or any other tooling - real agricultural blacksmithing. I used a section of tree stump as an anvil. So centring the eye is a touch beyond me at the moment.

QUESTION: In most froes the location of the eye is centred on the blade and I am wondering - why do people centre the eye on froes? Tradition or is there a physics functional reason for doing so?

I still need:

• to straighten the blade a little more still his a small bend to it
• refine the bevels on a linisher
• grind the surface clean
• and make a proper handle.

I want to make a tapered drift from a section of solid rod ground with a taper. This will help me make a nicer tapered eye.

However the concept worked even with the offset eye. I have another piece of leaf spring that has the eye pre centred. I will plan to work on that one tomorrow.

IMG_0219.jpg IMG_0218.jpg IMG_0217.jpg IMG_0214.jpg

well done!! I'm not aware of any froes that will hang with a 5160 leaf spring, though haven't checked the ones you mention for several hundred dollars. the cheap ones here are unhardened or very low carbon steels, and the others as I recall may be something like 1045 or something.

Looks great and will last forever.

others hit on the handle already - I recall seeing one or two offered for sale here with the handle at an offset angle, but have no familiarity. One may be better in a certain fixture for shingles or shakes or for all we know, ash stripping for baskets and chairs.

But enough are straight that I'd have started there, too.

Originally Posted by MartinCH

Hi All

Unbending, het treating and tempering a truck spring sounded a bit challenging, even more so after reading Paul's posts. IHB 3 asked the local steel supplier for cost of 300x50x10 bisalloy HB500. Rockwell about 51 I think. Including laser cutting quote was $28. Less cost again if there was suitable off cut, available.
(note there are several versions of wear/hard plate)

I think once you have a forge and/or bar laying around, it takes less time to make a tool like this than it would to make a trip and communicate it to someone else. that's perhaps not the case at the outset. some things are easier to do while the steel is soft, too, like any serious changes in dimensions that you'd desire (like tapering if wanting to do that), and cutting substantial long bevels or first forging them part of the way.