Welding Tips and Tricks

So I picked up this piece of steel along with some other scrap steel on my semi-weekly run to the steel shop. It was in the scrap section where I got all my other mild steel, but apparently it's not what I normally get. I went to bend up a support bracket for the welding cart I'm building, and it cracked right off in the press!

It looks a little different than the normal mild steel that I get, but I figured it just had a different type of mill scale or something. But now that I look at it closer, it doesn't really have any mill scale on it, just a dull shine.

I think I have a few other flat bars out of this same stuff, including some nice 4" wide 5/8" thick stuff that appears to have the same finish on it. I just hadn't gotten around to actually using that stuff yet. I picked it up because it was thicker than the flat bar that I usually see in the scrap section. The one in this photo is 2" wide 1/4" thick I think.

Any idea what it is? Apparently it's not bendable (without heat anyway). Is it weldable? What can I use this for?

Can I at least use it for gussets and feet/plates what not that don't need to be bent? I probably should have looked at it closer before I picked it out.

Have you tried to stick a magnet to it ? Does it have any rust on it ? Looks like cast stainless from what I can see , but that's a guess with out seeing it up close . Hope this helps .
Scot

Daniel,

Where do you buy your steel?

Yea, magnet sticks just fine. As for rust, I'm not sure, stuff doesn't usually rust in my garage unless it's been sitting there for several months, I just got this flat bar this weekend. I'll leave this little piece outside and see what happens, or put some vinegar on it.

Here's a video of the piece, so you can see the shine on it. maybe it's cast stainless?

If it is indeed cast stainless, is it worth holding onto for anything other than a leveling block on a table leg?

GlenC, I go to M&K in Gardena, it's the closest place to me. 14400 Figueroa St.



https://www.youtube.com/watch?v=LEbWF95 ... e=youtu.be

Hey Daniel , if the magnet stuck then it's not stainless , your photo appears like the metal was new and was using that as an aid to ID it , sometimes you will see a slight flash rust on the metal which stainless won't have . Since it tore while bending I'm not sure what you have . Sorry . Also some stainless has a slight magnetism to it , like 400 series to allow heat treatment . I guess I'm no help , but hope someone else can help you .
Scot

no worries, I appreciate the help!

I'll try a magnet side by side to some mild steel, see if it has a similar strength of attraction. It did feel like it wasn't QUITE as strong of a stick as mild steel. I could use a fishing scale to see what % attraction it has versus mild steel.


In any case, until I find out what it is, and what it should / shouldn't be used for, I'm just not going to use it for anything accept when I need a shim to temporarily prop something up.

Try a spark test to help identify the metal.
https://www.youtube.com/watch?v=D094eBa4S7c
https://www.youtube.com/watch?v=Yq2FwCn3qFA

Some stainless is very magnetic.

Some 304 from China lies about it's composition, and likewise is very magnetic.

The grain structure in the break suggests cast or wrought. Either way, a very coarse grain suggesting it would not weld well, and be prone to cracking as it cooled.

Steve S

I think it is simply cold told steel. I have tried to bend cold rolled in a press before and that is exactly what happens. It is good material, use it for your brackets. It is stronger than A36 but as you see it is more brittle.
-Jonathan

tried the magnets again, it feels about the same amount of force to pull off the magnet, compared with mild steel.

I'll take the broken chunk to the steel shop next time, and see if they know exactly what it is.

If it is indeed cold rolled steel, I assume it's ok to drill into that for brackets and such? I'll do some welding tests next time I get a chance. Which will probably be next weekend, might as well just take the piece to the metal shop and see what they say

Spark test on the grinder. There is charts/photos online that will help crudely identify it by the sparks it throws.

ETA: I see Werkspace already mentioned that.

Oh, I missed that reply about the sparks, I'll try that! I'll compare it with mild steel, which is the only other ferrous metal that I have.

danielbuck wrote:Oh, I missed that reply about the sparks, I'll try that!

Alternately, after determining what 'type' of steel it is with the spark test, you can try to anneal a piece of it and then see how it bends.