Thread: magnetic cylindrical square

Yes the youngs modulus is for all practical reasons the same...

A dead soft mild steel low carbon bar up to it's yield point will with the same load, bend the same amount as a high carbon bar...

The yield point is the point at which the material will permanently deform under load...

Originally Posted by .RC.

Yes the youngs modulus is for all practical reasons the same...

A dead soft mild steel low carbon bar up to it's yield point will with the same load, bend the same amount as a high carbon bar...

The yield point is the point at which the material will permanently deform under load...

I don't see how this applies to the subject. How does yield point relate to the sag of a bit of wire. Yield point is where the wire deforms permanently.

If I take a piece of spring wire and a piece of soft wire and hang an equal weight at equal length from the mount point of both of them, the spring wire will resist bending far more than the soft wire. It will deform less.

This has confused me for a long time. I have read how mild steel is just as good for lathe tool holders, as high carbon steel is. There are steel grades that are designed to be rigid, and to reduce deforming, after heat treatment. Maybe it is the heat treatment that changes the "Youngs Modullus" relationship.

Dean

I was pointing out that all steels sag the same amount (or close to it) up to the particular type of steel's yield point... After that point is reached all bets are off when it comes to sagging...

Originally Posted by .RC.

I was pointing out that all steels sag the same amount (or close to it) up to the particular type of steel's yield point... After that point is reached all bets are off when it comes to sagging...

What I was talking about is that a spring does not follow that convention. Think about it. A spring's purpose is not to sag. A sagging spring is "worn out".

This is why I said

Maybe it is the heat treatment that changes the "Youngs Modullus" relationship.

.

Does "Youngs Modullus" only refer to steel that has not been heat treated in any way?

Dean

Originally Posted by Oldneweng

What I was talking about is that a spring does not follow that convention.

Yes it does... It just has a high yield strength close to the UTS (Ultimate Tensile Strength)

Does "Youngs Modullus" only refer to steel that has not been heat treated in any way?

It refers to all steel in general... Does not matter..

Originally Posted by .RC.

Yes it does... It just has a high yield strength close to the UTS (Ultimate Tensile Strength)



It refers to all steel in general... Does not matter..

Can you do me a favour .RC. Go back and read my posts slowly with an "open" mind because it appears to me that you have not understood my actual question.

Forget yield strength. Think only of sag.

If I take a piece of spring wire and a piece of soft wire and hang an equal weight at equal length from the mount point of both of them, the spring wire will resist bending far more than the soft wire. It will deform less.

Go and test this. I can guarantee that a spring will not sag as much as mild steel.

Dean

The soft wire sags more because it's being pushed beyond it's yield point.

If NOT pushed past it's yield point (by using an appropriate sized weight), both the soft and high tensile wire will deflect the same amount for the same weight.

Or have I also misunderstood what you are asking?

Originally Posted by Vernonv

The soft wire sags more because it's being pushed beyond it's yield point.

If NOT pushed past it's yield point (by using an appropriate sized weight), both the soft and high tensile wire will deflect the same amount for the same weight.

Or have I also misunderstood what you are asking?

I find it hard to comprehend that a high tensile steel such as a crow bar has equal bend strength to mild steel. So the moment the high tensile bar bends, the mild steel would have reached its yield point, roughly speaking.

Dean

Originally Posted by Oldneweng

I find it hard to comprehend that a high tensile steel such as a crow bar has equal bend strength to mild steel.

Yep, but it's true. The wire example you used is probably not the best example to use to conceptualise this, unless you start considering very short lengths of wire and very small weights.

Originally Posted by Oldneweng

So the moment the high tensile bar bends, the mild steel would have reached its yield point, roughly speaking.

Possibly ... the exact figure could certainly be calculated.

Originally Posted by Oldneweng

I find it hard to comprehend that a high tensile steel such as a crow bar has equal bend strength to mild steel. So the moment the high tensile bar bends, the mild steel would have reached its yield point, roughly speaking.

Dean

No, they both bend at the same rate.. Any load will deform the bar by some amount, even if unmeasurable by human means.

Look up the Modulus of Elasticity in this table

http://www.engineersedge.com/manufac...s_strength.htm

Originally Posted by .RC.

No, they both bend at the same rate.. Any load will deform the bar by some amount, even if unmeasurable by human means.

Look up the Modulus of Elasticity in this table

http://www.engineersedge.com/manufac...s_strength.htm

That was just me getting around the concept.

I have read about "Youngs Modullus". At the moment that would be a hindrance.

I prefer to be wrong in this case, as then the idea of making insert holders becomes more viable. I cannot afford to buy all I need at the moment. They are not difficult to make.

Dean