Not only rebar is junk steel containing anything but Cast Iron flanges
are the same.
I tried to weld some big box 1" iron pipe wall flanges for a lady
customer. She bought cheap. They melted like butter. A little heat a
major slump.

I went to my local hardware store and he had made in America flanges.
They welded nicely.
Oh yes - I was using a black stick with nickel in it. That works nicely
on cast iron.

Got the job done.

When plasma cnc cutting sheet steel from overseas rolling mill, it had
ball bearings and races in it. I'd cut nicely down a line then the
steel took a lot more heat to cut but the CNC
didn't know and stops cutting until it hits nice metal. Constant
re-starts until it was good.
I told my vendor and he changed suppliers. Most of his customers used
oxy torches and
never mentioned it.

Rebar has dozens of numbers - salt water protected, epoxy coated,
Certain types of steel.

Martin

On 11/9/2018 11:20 AM, Bob LaFrance wrote:
On Friday, November 9, 2018 at 7:42:13 AM UTC-5, Gunner Asch wrote:
On Thu, 08 Nov 2018 17:58:58 -0800, Larry Jaques
wrote:

On Thu, 8 Nov 2018 07:10:13 -0800 (PST),
wrote:

Greetings.

I am making a lamp for my living room. I will use a 45 pound plate for the base and some 1/2" rebar for the lamp itself. Base will be on one wall and light bulb will be about 7' away. I need to bend an 11' piece of rebar into a perfect arc. It would be 180 degrees of a circle. I am thinking to make a fixture out of plywood. Fixture would be similar to what an electrician would use to bend conduit. I don't intend on heating rebar. Just bend on fixture. Other way would be to create a fixture using a complete sheet of plywood. I think that is overkill.

Any thoughts?

Unless you use Carl's suggested method, you'll need one of these:
https://www.youtube.com/watch?v=jXWzIgfTuuQ

Just remember..there is a **** ton of rebar out there that will snap
in half if you look at it funny. A lot of rebar is Asian..and they
make it using every bit of scrap that they can find. If it happens to
have been poured from a melted own pile of cast iron...you are
screwed.

The only reason I mentioned this..a buddy was pouring a slab around
his pool and we were forming and rebarring it..and it kept snapping in
half every time we tried to bend it (with a rigid conduit bender)

Gunner
__

"Poor widdle Wudy...mentally ill, lies constantly, doesnt know who he is, or even what gender "he" is.

No more pathetic creature has ever walked the earth. But...he is locked into a mental hospital for the safety of the public.

Which is a very good thing."

Asun rauhassa, valmistaudun sotaan.


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Thank you. I will keep that in mind when I decide what I am going to hang from the rebar in my driveway - something very light and small, I expect these things will dance a little with a breeze so I wouldn't want to hang a sail at the end. I will put motion detectors on each lamp so should be cool driving up the driveway. Thanks