Technical High Strength Steel from Scrap Yards

I have been running into a bit of high strength steel in my s**** yard finds. I was making someting and needed to machine it after cutting. It was hard as hell. The grind test produced a lot of sparks. The stuff may cause problems when welded or during fab work. Just a heads up.

 

That is one of the problems with s**** steel. You often don't know what you are buying.
There is a "gun" that is used on metals to tell you what it is. The salvage metal guy by me will use it if you need a special material for some reason.

 

All the drops end up in someones s**** bin, whether it's cobble plate, or high strength. I work for a large equipment manufacturer, we burn a lot of plate in house, mild steel to specialized high strength. It all goes into the same bin.

There are portable rockwell and brinell test devices, kinda pricey just to have around though.

Maybe some of the experienced machinists can chime in with an easy, field test.

What thickness plate are you buying where you're finding this?

 

Bring a file with you when you go shopping, this is the best and simplest test for an unknown steel, and a magnet.

 

Wonder if there's a manual spark test method?

 

Spark test video. JC

 

The author replies! Thanks.
I wondered about using a file as a tool.
(Suppose degree of softness would reveal)

 

When I was in the fabshop, we had some hard plate steel we used for wear conditions on equipment. It looked exactly like plate steel but you could not shear it or use the punch press on it, same went for trying to drill holes in it. We had to cut it with a cutting torch. It came in large sheets and had a yellow paint lightly painted on it to make it identifiable.

 

Takes you by surprise when it in different shapes like angle and channel and square tube too..I have aquired a feel by site for some of it but when in doubt I spark a coner edge with battery & jumper cables, if a file can't touch it then it is not mild steel..

 

^^^ Been known to do that...ooops!

 

Sometimes if I don't have a file I hit the edge with a known piece of mild steel, the dents/nicks should look the same.

 

I own a fab shop. I get calls all the time for guys who want to bring me plate they bought off craigslist to shear. "The guy I bought it from told me it was A36"
Some of them get angry when I refuse to cut it for them. They have never had to pay to repair or replace a shear blade.

 

Always purchase from your local steel supplier----Saves grief!

 

Although a friend will apply the "smell" test, and impress some unfamiliar with metals, I don't think there's much merit to it. ( We kid around about it when there's obvious novices in the vicinity)

This works surprisingly well and costs little.

 

Yes but matters more after you weld it, lot of stuff is pretty file able until heat gets put to it...

 

Seb, I welded some lug holes in a C4 vette rear wheel flange. (Was converting to 4.5 Ford Pattern)
I guess the carbon migrated...as any pilot-hole near a weld would not drill!
It took a diamond wheel to nibble the dia. open.

 

Worked in a steel mill for 40 years.
We had 110 different steel grades you could pick from

 

I picked up some s****s from a closed machine shop, all kinds of cool stuff but one chunk 4''x6''x12'' has been my anvil (and a good one) for about 10 years. I think it is D2

 

If you know what you're doing. I've been doing it for over 30 years, went through a pallet of forgings that were supposed to be a rockwell 38 a few years ago. We were having tool-life issues and I culled out the ones I thought were too hard, just by using a file. I said they were a 50 and a real hardness check supported my findings.

 

I'm no pro or machinist but I have built a lot of stuff in my life. When I need steel for a project like a fab bench or tool cart I visit the drop and s**** section of the local steel distributor. Almost any angle iron or square tubeing with an electro welded seam will be mild steel and be all you need. If I am building something that requires a specific material I go to the counter and have the sales guy write up the order then go to the door and they load it.

I would bet that almost any project for a hot rod including the frame could be built with mild steel and be adequate. Maybe an occaisional gusset in a stress area but it would be easy to weld and finish and not need anything more exotic than a garage quality MIG or stick welder.

 

D2 is the most wear resistant alloy steel I've used. When cryogenically heat treated, it simply doesn't wear.

 

I'm with aaggie. I get a lot of stuff from the local metals supplier in my area. They sell the cut-offs at s**** price. Might take a trip of two until they have what you need on the s**** rack. But it's well worth the wait. And they know what type it is.

 

Bed angle rails are hard but crack when welded. Made from railroad rails.

 

D2 has a high chromium content with molybdenum (good for toughness) and vanadium (single-point hardness). I first used it to replace some punches in a die set. Air hardening, so it does well dimensionally after heat treatment.

 

D2 is some nasty stuff to machine/grind/process in any manner after H.T.

 

Grinding is not bad if you allow so much per-side on a diameter.. machining... go fish, your mileage may vary.