Steel Plate : Rounded Factory Edge

[stickermigtigger]

I picked up a 4x8 sheet of 3/4" plate off Craigslist ($375). The two long edges are factory rounded. The short edges are square.

All the plate I've ever bought/seen was squared off all sides.

Does the rounding say something about the type or properties or purpose of the steel? (armor, A36, ?????)

[tarry99]

Well first off that was cheap for a 48"x 96" x 3/4" plate.........but rounded corners tells me that was a non Mill service center purchase unless special ordered.......The norm for plate coming out of the Mill is 96" or 120"wide x 240" sheets in 3/4" and then sized down by burning from there ..............does it look ground-over or machined ?

[stickermigtigger]

Still covered in mill scale and a bit of surface rust. I wire wheeled the rust off. I’m not sure what it should look like if milled. The cut edges are nice and sharp. I’ll post a pic when I get to a PC.

Price? Yeah. I hauled a tractor to SC to get it like, ten minutes after the ad was posted

[tarry99]

What is your definition of Factory rounded?........If it was milled by a tool , I would assume it to be a very clean 1/4 round continuous cut finish along the length........If it was rolled over with a grinding wheel by hand it would be much rougher and probably not as perfect a radius as the machine milling.
I guess the big question is what are you going to use it for? Workbench? or just cutting it up as you need it?

[stickermigtigger]

First: my bad, it’s the 4’ edges that are rounded.

“Factory Rounded”: no one. Is that good with a grinder. There may be a shop tool for that purpose, but I’m not aware of it.

[BukitCase]

Here ya go;
https://www.amazon.com/SHARS-4X3-Cor...s_id=340045011

Then all you'd need is a mill that has at least 4' of table travel, and some REALLY heavy roller stands :=) ... Steve

[MMW]

Probably came out of the mill 96" wide and then was cut into 48" sheets. Side edges come rounded from the mill to keep a uniform shape. Usually very high carbon content right on the edge. Congrats on the find.

What material is it, who knows. A sheared edge usually is A36 mild steel. A burned edge can be anything. Is the "squared" edge burned or sheared?

[G-ManBart]

Is the rounding just on the top of the 4' ends? Is it just a slight bit of rounding? If so, that could simply be from the shearing process.

[ryanjones2150]

As I recall the heavy sheets I’ve purchased have never had square cut ends, more of a curve-ish punched through looking edge.

[tarry99]

PICTURES would be great...........

[stickermigtigger]

[Bushytails]

And today's award for "this is why cell phones are not replacements for cameras" goes to...

[Bushytails]

I'd always assumed the rounded edge was just the result of rolling out the hot plate, and square edges were where it was cut.

[tarry99]

That picture almost gives the impression of two 45's ground and a flat in the middle which could be the prep for welding it together , prior to rolling or forming it.?

Been inside many rolling mill's all over the West and the only time you see and end unfinished and rounded off would just be the scrap lead or finish end after the rolling process on a large ingot is finished, which would then either be sheared off if it was thin enough......or on heavy plate would be gas burned off on the ends......... the sides of the plate as it comes through the rolling mill hot is constantly mechanically messaged for size on both sides while it travels through the process.

[aametalmaster]

The rounded edge is the factory. Most sheets are cut from bigger sheets so the square edge is the recut edge.