Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Hi Guys!

When the frame on a riding mower is described as "drawn steel", exactly what does that mean? Is it a "quality" method of manufacturing the frame?

Thanks,

Marc

I wonder what they really are trying to say with this "sales pitch". If they are really serious, the salesperson should be able to easily explain why "drawn steel" is different and better than what else may be used in other machines.

The chart looks like cold drawn is harder, has a higher tensile strength (my understanding is resistance to bending) and a higher yeild strength (my understanding is how much does it take to pull it apart). How does forming or welding effect these properties? Since it also says harder, maybe that's why it seems to crack more easily.

When I think of a mower frame I think of a sheet bent into a channel, square or rectangular tube, or angle.

If you take a steel bolt for example, the sheer strength of the bolt anchored in concrete for example, is the force at which it would be sheared or broken in half from weight. The Tensile strength would be at what force in weight that same bolt anchored in concrete would be pulled strait out or become broken by the same type of force.

For example, if I had a steel bolt in a ceiling pointing strait down and applied enough force pulling downward on it, that would test it's tensile strength or "Ultimate Elongation" (stretching).  If I pulled sideways or horizontally on it, that would test it's shear strength, (pulling apart sideways). The same applies to steel in form of a bar, strip, channel, etc.

I have seen steel tested for these two strengths, and a third strength too. The machines they use are pretty cool. You would be amazed at the sound steel makes when it is pulled from both ends, stretches and snaps. Pretty loud!

Yield is more of a measurement of the amount of stress to produce an offset. For steel an offset is usually .02% change of it's original form. That's a very simplistic answer, it can get about as technical as a person desires. You can get into elasticity and all I have no desire for that, LOL.

As to which is better for a mower frame, who knows? There's so much more that goes into steel than just these few things. I strongly imagine very good as well as very poor frames could made of both.

Do I have yeild and tensile backwards?

Yep.