Rating Of Steel?

[ox3782]

I have been studying the yeild charts and notied the lack of a few things and was curious if anyone could help.Does anyone know what a 40d nail yeilds at?Also I have notied something I cant explain,on the yeild charts I have looked at they rate 50d

nails at 300lbs and 60d nails at 283-299 I know the 60d is 1/2 inch longer but I can completely bend a 50d and have bent many

but can only bareley kink a 60d any Ideas?

Thanks

Brendan

[makey98]

I am not the expert on this, but basically you can't accurately compare poundages of steel at different lengths. For instance the two steels below calibrate the same but the Bastard is MUCH harder from what I have heard. (I will let you know when I can bend one! )

5.5 inch Grd 5 from FBBC calibrates at 445lbs

7 inch Bastard from FBBC calibrates at 440 lbs

Basically you can only compare poundages of the same length and 50D's are 5 inches right? Also, there is quite a bit of variation in 60d's

Weak Lowes 60d = 210

HD skinny 60d common = 240

Griprite shiny 60d common = 265

Keystone non-galv. common = 330

Sivaco green 60d nail = 380

[ox3782]

I am not the expert on this, but basically you can't accurately compare poundages of steel at different lengths. For instance the two steels below calibrate the same but the Bastard is MUCH harder from what I have heard. (I will let you know when I can bend one! )

5.5 inch Grd 5 from FBBC calibrates at 445lbs

7 inch Bastard from FBBC calibrates at 440 lbs

Basically you can only compare poundages of the same length and 50D's are 5 inches right? Also, there is quite a bit of variation in 60d's

Weak Lowes 60d = 210

HD skinny 60d common = 240

Griprite shiny 60d common = 265

Keystone non-galv. common = 330

Sivaco green 60d nail = 380

Thanks for the Info on the 60's.The 50d nails are 5.5 inches and 40d's are 5 inches. Also the 60d's I have been attempting I got from a local harware store and they are galv coated.

Edited April 12, 2007 by ox3782

[Tim71]

I had Eric calibrate a 40d for me and I don't have the results in front of me but I want to say 260 lbs. It was a tougher one and I knew it. Like mentioned, the longer the length typically the tougher the bend even if the numbers are the same.

The galvanized nails vary alot too. My toughest galvanized nail hit 320 where the weakest hit 210. The 210 is crazy low for a 60d nail quite honestly.

You see the figures quoted by makey98 which I think are the ones I gave him. That 380 nail is mean but I've got a few examples of the same brand but a different batch that are hardened or something and they hit 480 lbs. Much tougher to bend than a G8 in my opinion.

50d nails are very hard to find. I've only got a few in my collection.

Tim

[ox3782]

Very interesting on the longer the length the tougher the bend it makes sense to the poundage ratings vs what I have been feeling you would think the opposite but it certainly dosent feel it.And yes the 50d's are extremley hard to find I bought some at a small hardware store when I first started bending and i have not been able to find any since I just let my last one go to a

kid at work and he bent it to full kink terrible form needs more wrist.Anyway thanks for the info and I will keep at it and practice and build my strength with the longer stuff and the 60d will fall.

[crobb1320]

ok i got a question,i've seen this more than once ,but how can a longer bar of the same diameter and material be harder to bend? what about the whole leverage thing? like the first 2 ironmind nails,white and green i think, both being 3/16" dia. white being an inch longer and the easier of the 2. take the inch off and you lose some leverage which makes it harder to bend. please somebody correct me if i'm wrong.

[Tim71]

Didn't say the same diameter and same material. I'll try to explain it and keep in mind this would really apply to 5 inch to 7 inch lengths.

First, let's say a 1/4 inch piece of CRS calibrates at 240 lbs at the 7 inch length. Well, at 6 inches it's going to calibrate at about 300 to 310 lbs. The 6 incher will be harder to bend. Now, take a 9/32 piece of CRS at 7 inches and I think it calibrates around 295. It had to be thicker to get the same poundage rating since it's longer. However, it's going to feel much harder to bend. But take the 9/32 and cut it down to 6 inches and it will be harder still to bend because the pounds will probably be 380 to 400 lbs.

Now, in a calibration device such as Eric's, the weight is applied to the center while being suspended 3/4 inch from the ends. However, when you bend a bar there's no fulcrum in the middle. So even though the above bars calibrated almost identical the 7 incher will be harder because your hands are farther away from the fulcrum point. Like moving your hand farther out to the end on a sledge hammer.

Hope this helps as it's not real easy to explain. One kinda offsets the other but not to the same degree. Basically to me a 7 inch nail that calibrates at 300 lbs feels about as hard as a 6 incher that hits over 350 or so.

Tim

[ox3782]

Didn't say the same diameter and same material. I'll try to explain it and keep in mind this would really apply to 5 inch to 7 inch lengths.

First, let's say a 1/4 inch piece of CRS calibrates at 240 lbs at the 7 inch length. Well, at 6 inches it's going to calibrate at about 300 to 310 lbs. The 6 incher will be harder to bend. Now, take a 9/32 piece of CRS at 7 inches and I think it calibrates around 295. It had to be thicker to get the same poundage rating since it's longer. However, it's going to feel much harder to bend. But take the 9/32 and cut it down to 6 inches and it will be harder still to bend because the pounds will probably be 380 to 400 lbs.

Now, in a calibration device such as Eric's, the weight is applied to the center while being suspended 3/4 inch from the ends. However, when you bend a bar there's no fulcrum in the middle. So even though the above bars calibrated almost identical the 7 incher will be harder because your hands are farther away from the fulcrum point. Like moving your hand farther out to the end on a sledge hammer.

Hope this helps as it's not real easy to explain. One kinda offsets the other but not to the same degree. Basically to me a 7 inch nail that calibrates at 300 lbs feels about as hard as a 6 incher that hits over 350 or so.

Tim

That nailed it for me Thanks Tim

[makey98]

Yeah Tim is right on his calibrations! He loves talking about steel! I love it! Those were the calibrations he gave me. Thanks again.

Anyway, the way that I tried to think about this to understand how different lengths of steel calibrate differently is not due the fact that one is stronger versus weaker but just in the way the Eric Milfield is calibrating this steel.

He is NOT measuring how much force it takes a person to bend a bar. He is measuring the amount of weight that it takes to bend a bar with the weight hanging in the middle. So different lengths mean that each length has a different fulcrum like Tim said. Just like it is easier to bend a 10 foot piece of steel than a 1 foot piece of steel. The strength of the steel doesn't change but the increased leverage allows you to apply more force.

Basically the calibrations that we use don't really measure the force it takes to bend the steel but it just gives a reference point to compare different steels to each other.

[crobb1320]

got it tim,that makes good sense.

[com202]

I couldn't have said it better myself.

Good explanation guys.

BTW.... When Eric calibrates steel he finds the weight that bends the steel to 30 degrees.