concerning shredder blades-Any metallurgists out there?Maybe a welder can answer this

[whistlepig]

Years ago I had some lawn mower blades hard faced with stellite welding rods at work. They were too hard and chipped so easily that I would gave gotten longer blade life if I simply had left them alone.

 

[Kyle_in_Tex]

Years ago I had some lawn mower blades hard faced with stellite welding rods at work. They were too hard and chipped so easily that I would gave gotten longer blade life if I simply had left them alone.

I believe that. Stellite is hard and so different from the base material. I see that some blades for sale are made from 5160 spring steel, hardened to 38-44. I wouldn't have guessed them to be that hard. I need to look at the yields and tensile numbers too.

 

[whistlepig]

Any stainless makes for a poor cutting edge. High speed steel is a lot more durable than a stellite edge. High speed steel would not weld well. When making custom tools using high speed steel we use silver solder as high speed would disintegrate when welded.

 

[Kyle_in_Tex]

I have some silver solder at work.

 

[whistlepig]

I am a machinist by trade also. Let us know how things go for you. We may learn something here

 

[TerryR]

It seems clear that those responding are confused about what the question is. Is the OP talking about a rotary cutter (also known as a Bush Hog, or in some places as a shredder) or an attachment for shredding brush and small limbs, as in chipper/shredder? Some of the answers apply to one, and others apply to the other.

Terry

 

[whistlepig]

Steel is steel. Blades are blades. No matter what they are attached to and no matter what they cut. If you have the perfect steel to eliminate our confusion please share.

 

[Kyle_in_Tex]

These are for rotary brush cutters, Bush Hog type.

Bush Hog Rotary Cutter Blade - Bush Hog 36, 24-5/8 in. L - Tractor Supply Co.

 

[bigtiller]

Any stainless makes for a poor cutting edge. High speed steel is a lot more durable than a stellite edge. High speed steel would not weld well. When making custom tools using high speed steel we use silver solder as high speed would disintegrate when welded.

I think I would rather use a brazing rod..... I think you are using a common slang term but some beginner may try to buy some silver solder for the repair.

Silver solder is what jewelers use to repair jewelry.

 

[RedNeckGeek]

I do have rocks. Up to potato size pieces of flint and my blades end up looking like hammered dog crap. That being said, it would be a total government project (free labor and machine time).

I feel your pain. I've been out 'hoggin' for the last few days, chopping down the grasses and weeds on about 8 acres of hillside. Lots of buried stumps and rocks that I just can't see under the tall grass, and the first thing I hear about it is the ruckus under the mower deck. Stump jumpers can only do so much, and today I hit a stump so hard it oil canned the deck so the blade mount was rubbing:



A few minutes with a 4' pry bar got things more or less back into shape, but while I was under there I took a few shots of the blades themselves:



I bought the 'hog used, and I thought the blades were bad then. I straightened them out with a mill, but since I'd never used a brush hog before on rough ground, I really had no idea of what I was getting into:



I think I'd really have to think hard about spending a lot of time on fancy, time consuming machining, welding/brazing, and heat treating in light of what's GOING to happen first time you hit a rock (when, not if). I'd also plan for the worst, and hope for the best. That is to say I wouldn't try anything that could even remotely result in a chunk of metal breaking off the blade and exiting through the side of the mower deck. It's bad enough when chunks of wood and stone get shot out by the blades, but metal is a lot more dense, will travel farther, and have more energy at the end of its trajectory. For that reason I'd maybe start looking at some sort of hard facing operation that would build up the edge maybe ten or fifteen thousandths, leaving the ductile material of the original blade just below the surface to keep things together when it hits something hard. Grind that back to a nice high angle edge and you might get a better cut and not cry so much when you have to do it over first time the inevitable happens.