Need to straighten 1/4" steel cultivator arms

[AmericanTractorDriver]

Hello,

I recently purchased a used 2-row cultivator, and several of the 1/4 x 1-1/2" C-springs that hold the chisel teeth are bent. I need to straighten them. What's the best way, short of having access to a fab shop? Doubt a propane torch would be enough heat.

Thanks

[Egon]

Unless you can retemper the entire spring you may as well get new ones.

[Baby Grand]

Like Egon said - buying new C-shanks may be the easiest way to get that cultivator back in service. AgriSupply probably has something that will work. Spot heating may allow you to get the shape you want, but it will probably also result in a soft spot where it's been heated that's likely to bend at that spot easily, undoing the repair you just made.

If you're up for a DIY blacksmithing adventure, you'd need to anneal the springs so that you can deform them to the required shape. Then you'd need to reharden and retemper them by heating and drawing them - requiring a quench in oil or similar fluid.

Knucklebuster » Blog Archive » How to Anneal, Harden and Temper Steel

Not a trivial undertaking for a large piece of steel.

[sixdogs]

A picture would be nice to see what kind of spring and where the bend is. Most of the one I see bent are on the old 1950's 7 ft wide Dearborn types and occur near the flat spot on the spring. I'll guess this is what you have. I can whack these minor bends with a big hammer on an anvil and straighten most of them. Heat not a good idea.

[AmericanTractorDriver]

A picture would be nice to see what kind of spring and where the bend is. Most of the one I see bent are on the old 1950's 7 ft wide Dearborn types and occur near the flat spot on the spring. I'll guess this is what you have. I can whack these minor bends with a big hammer on an anvil and straighten most of them. Heat not a good idea.

Here is the arm in question. I wonder if a shop press would take the bend out. May be much easier to find a local fab shop that'll straighten them for a few bucks, versus building a furnace. And I have some Rustoleum Rusty Metal Primer, once I get it cleaned up

[sixdogs]

That's the type of cultivator I suspected and I have straightened them before. It's a typical "Dearborn" style.

Here's how I do it. Unscrew the bolt on the end and take the two leafs out. I have a heavy 4 or 5 lb flat faced hammer so I place the spring on an anvil and whack it flat. You do not have a bad bend and it should be easy. Maybe don't hit the center of the bend but work your way towards it. Wear safety glasses. This does not look like a big deal and the bends look relatively minor. When you reassemble things the leafs won't exactly mate flat together but don't worry about it. It's no big deal. A hammer would work way better and easier than a shop press.

If you don't have a flat faced hammer any heavy one will do and I also cut most of the handle off a 6 lb sledge and have used that. No anvil? Find something flat and heavy and hope for the best. These bends are no big deal. A few hammer blows and you're back in business.

These are great cultivators and taken apart and repainted Ford Red or MF Gray they look pretty nice. There is a small metal washer at the bottom of each tine that you should save but AgriSupply Farm Equip carries them mail order. The cultivator shovels are a slightly different angle so don't buy them at TSC and expect them to fit. Oops, the angle won't matter with your "chisel" type points.

Not sure how that cultivator got bent. It's near impossible to do it in use so my guess it the equipment was transported to auction and they set something heavy on top of it. Who knows. Nice cultivator.

[sixdogs]

Here's one I have.

[npalen]

Adding to what sixdogs advises, I might suggest putting a couple blocks of, say, 2x4s, one at each end of the bent area and then straightening with the hammer or press. I'm thinking that you will need to overbend a little to allow for springback unless this is fairly soft material.

[Egon]

Just remember that spring steel once bent has been strain hardened and will bend again under less force than the other shanks?

[SPYDERLK]

Adding to what sixdogs advises, I might suggest putting a couple blocks of, say, 2x4s, one at each end of the bent area and then straightening with the hammer or press. I'm thinking that you will need to overbend a little to allow for springback unless this is fairly soft material.

Yes. ... And dont hit it directly with the hammer. Lay a small section of ~ 1/8" metal where the blow will fall. A hammer face will dent and thus stretch the metal ... and the center of the bend needs to contract/shrink to straighten.
larry