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Bob Lipinski

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Bent a 6" 1/4 round like butter, then had a bitch of a time kinking 1/4 8" square stock. Is this unusual?

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I personally haven't bent any square, but from what I hear that's to be expected.

Were both rods of the same brand of steel?

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Bob,

Even if both rods were the same strength steel the 1/4" square is a larger cross section than the 1/4" round and thus a more difficult bend. Still, it does sound like your round stock is a lot softer than your square stock if you can only kink an 8" piece.

Robert

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Yeah, I knkew the square would be tougher, I was just suprised how much. After my MM certification I will give a 9 inch piece a go, and if that doesn't work I'll just do shorter 1/4 stuff.

I bought the both rods from Home Depot.

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the 1/4" square from Home Depot is about as hard as a grade 5. Really tough stuff.

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I bought some square stock from a local hardware store and could only put a small kink in a 6"x1/4" piece. I think it is tougher than a Grade 5.

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I will have to pick up some square 0.25" stock from Home Depot.

Does anyone know how the square stock matches up against 60D nails? I am guessing that a 6" piece would be in the same range as a medium 60D nail.

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A six inch 1/4 square would be much harder then any 60D I've tried.

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A six inch 1/4 square would be much harder then any 60D I've tried.

This stock must be hardened steel, since the Timber Ties i bought are twisted 1/4" square stock. The Timber Ties are ~5.5" Blue nail in difficulty.

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Where did you get those Timber Ties? Mine are easier than a yellow.

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Last night I bent a 235k bar and I can definitely say that my square stock is tougher. I can also say with some certainty that the grade 5's I've bent have fallen between 230k and 235k. I'm hoping to put down a 240k in the next couple of weeks.

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Where did you get those Timber Ties?  Mine are easier than a yellow.

Lowe's, but there is a big strength range, even within the same brand (Grip-Rite). These are not far off from an average 60D. Much tougher than a Blue.

I measured them last night and they are 0.23" square, not 0.25".

Edited by RSW
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Guys-

When I was making the first 56 lb wt for height for FBBC, I dusted off the geometry part of my brain & figured out the difference. On a piece of square stock, you're bending about 50% more steel (roughly). I used 5" solid stock on the 56 & if you figure the area it would be pi x diameter or 3.14 x 5 for round stock equaling 15.7 square inches. 5" square is just L x W which comes to 25 sq in. A hell of a lot more steel in the "same" stock.

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Guys-

When I was making the first 56 lb wt for height for FBBC, I dusted off the geometry part of my brain & figured out the difference. On a piece of square stock, you're bending about 50% more steel (roughly). I used 5" solid stock on the 56 & if you figure the area it would be pi x diameter or 3.14 x 5 for round stock equaling 15.7 square inches. 5" square is just L x W which comes to 25 sq in. A hell of a lot more steel in the "same" stock.

You sure that isn't pi*r*r ? (3.14*2.5*2.5=19.625 sq.inch vs.25 sq.inch) So, the square stock has 1.25x the cross section of the round.

Robert

Edited by RSW
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Well, I did say my geometry was rusty....lol...it's been 20+ years. Pi x D is the circumference of the circle. Still, you're looking at 25% more steel for square stock.

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Its also a bit more complicated than just "more steel".

half of the extra steel in square stock is as far away from the fulcrum of the bend as possible as it is on the corners of the square.

In any bend the part of the steel that is resisting the bending the most is the "outside" of the steel furthest from the inside of the eventual U shape formed by the bend. This area of the bar ends up in tension and the inside under compression. This distribution of force is the reason buildings use I beams for construction as you get most of the strength of a piece of square stock with a fraction of the weight by having most of the steel under tension or compression as far away from the center of the beam as possible.

Its a bit hard to explain without diagrams but basically those little extra bits of steel that fill in the corners have a dissproportionate effect on the strength of the bar. It might only be 25% more area but the bars should be heaps harder.

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Octogen

Your post was about the I - beams was right on the money.

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Yeah its a bad side effect of being hanging out/being related to a bunch of engineers.

If anyone is interested i'm sure i can get a friend of mine who is an engineer to do the number crunching and tell us exactly how much harder square stock of the same steel should be.

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Speaking of round VS square. I've just got back into bending (let's say I had a 'catastrophic setback' in my strength training, it should suffice to say that I lost pretty much everything).

So I'm back to 3/16" stock. I've bent a 4.5" piece of the 3/16" stock I bought (which had blue ends so cold rolled?) into a staple and yet even an 8" piece of the 3/16" square stock I bought only gets a 20 degree bend or so on my (so far) best effort. I'm thinking they hold their square stock to higher standards but I'm going to have to get clever so far as finding a better stock to bend because the 3/16" stuff is getting prohibitvely short and the 1/4" stuff is still a bit too hard. I'm also starting to worry that it's not the other stock being to tough but, rather, my 3/16" stock might be weak. I'll have to go to a different hardware store and buy more this weekend.

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I'm glad to see you're recovering from your setback. The colored ends on your stock are not a universal code for any particular kind of steel. They're usually a designation for a particular manufacturer's stock thickness. Have you tried any 1/4" thick spiral nails (timber ties)?

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I'm glad to see you're recovering from your setback. The colored ends on your stock are not a universal code for any particular kind of steel. They're usually a designation for a particular manufacturer's stock thickness. Have you tried any 1/4" thick spiral nails (timber ties)?

What kind of stock is the steel if it is unlabeled(HRS OR CRS)? I bought some 1/4" square stock and 5/16" round at Home Depot but it didn't tell whether it was HRS or CRS. Some of the steel was labeled but none of the stocks mentioned above were, it just said steel bar. Thank you to anyone that can provide information.

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What kind of stock is the steel if it is unlabeled(HRS OR CRS)? I bought some 1/4" square stock and 5/16" round at Home Depot but it didn't tell whether it was HRS or CRS. Some of the steel was labeled but none of the stocks mentioned above were, it just said steel bar. Thank you to anyone that can provide information.

I would bet that it is HRS. I have never seen CRS at HD.

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