All Steel Created Equally !!! How to tell if steel is suitable for knives....

Battle Creek Knives

Battle Creek Knives

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well we all know this isn't the case.. but I have a question.......

I'm doing some sub-contract work for a big steel company here locally, they have virtually everything and I've been given the go ahead to pull scraps whenever I want...

I beams, angle iron, wrought iron, flat stock...... etc..

Although they work with steel everyday I'm sure none of them are metallurgist's, thus the reason for this thread..

their flat stock looks like the same stock I get for knifemaking but the steel is 'unknown'..

how does one determine the type of one steel over the other without rocket science.

I think I'm going to pick up a piece of 1/4" flat stock and make a super chopper out of one and see how well it holds an edge, but seeing I'm not currently making any more knives til my other projects are done this may be a while..

anyone have ideas in how to test metal/steel to see if its worthy???

thanks,

rob
 
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What type of steel company? Supplier? If it is a supplier look for painted identifiers. Higher carbon steels are a bit darker than regular Mild steel, though not as dark as Hot rolled steel(recast layer). Wish I could help out more.
 
the company orders in their material and makes various things from them, they even play with acm.. sheet metal etc.. anything you can think of...

I would never make a knife from 'unknown' steel with the intentions of selling it, however I'm very tempted to anneal a slab and make a chopper and see how it fares...
 
I would harden a scrap just to see if there is anything to it before bothering to make a blade from it.
 
For unknown steel I do a simple test of heating to the critical range of 10xx and quench. Hold on the edge of my anvil and give a swift wack to see if it is a higher carbon steel. If it snaps like glass you have something workable. Though it will be guess work if it is a chopper for your self go for it.

I picked up a ton of old plow blades and they work well for chopper steel. Would not sell one but I have givven a few away.
 
Heating to 1500F and quenching, then breaking without temper won't tell 1030 from 1095. They both will snap easily.

There is no way to know exactly what the steel is without an assay.
many tests ,like spark tests, quench tests, Doing a quench/temper and then Rc testing, etc. will tell you if it is hardenable, but won't tell you the actual alloy or how to properly HT it.

If you get 100 pounds of the same steel, and are sure it is all the same, the best thing would be to send a 1" square coupon to the lab for testing.
 
bladsmth said:
Heating to 1500F and quenching, then breaking without temper won't tell 1030 from 1095. They both will snap easily.

There is no way to know exactly what the steel is without an assay.
many tests ,like spark tests, quench tests, Doing a quench/temper and then Rc testing, etc. will tell you if it is hardenable, but won't tell you the actual alloy or how to properly HT it.

If you get 100 pounds of the same steel, and are sure it is all the same, the best thing would be to send a 1" square coupon to the lab for testing.
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Interesting, did not know 1030 would do that. I tried this test on what was suposed to be 1045 and it did not snap easy, not like 1095. Maybe it was not 1045?
 
Honestly, I would fill up the truck (and your buddy's, neighbor's and any other truck you can fill) with all the scraps you can get, take them to the recycling center and use the money to buy fresh, known steel. It will take a lot, scrap steel was running about 15 cents a pound last time I checked. There's a reason they don't care if you take it ;)

Mystery steel ain't worth the time you spend grinding it unless you get REAL lucky... and with construction steel, I sincerely doubt you'll get that lucky. Structural stuff, even the stainless, simply doesn't need the high levels of carbon a knifemaker wants.
 
I am really PO'ed. I just typed this twice, and it got lost in sending both times. Cable problems after the storm?


I saw the part about wrought iron and grinned. I severely doubt any big fabricator's shop has any real wrought iron laying around. Many people ( wrongly) call all decorative strip steel constructions "wrought" iron. The proper term is "Ornamental Iron". It is made from mild steel, not wrought iron.

What I was saying about the snap test was that while good knife blade steel will snap if heated, quenched, and hit with a hammer in a vise....so will many non-knife steels. Just because the good steel does it does not mean that all steel that does it is good steel. That is a perfect example of a specious argument.
I see this statement made in almost every thread on mystery steel, and it is totally false.

About your 1045 not snapping. That can be due to the quenchant,or the alloy. If the steel has .45% carbon, but other alloy ingredients, it isn't 1045 but many will call it that. The alloy ingredients may greatly retard brittleness and hardening. Quenching 1045 in a slow oil may leave it as pearlite.

Some alloys have 1% carbon or more....and won't make a good knife blade due to the alloy.
Some alloys have .30% carbon or less.....they may get brittle enough to break....but won't make a good knife blade.
A36, 1030, or the bar stock from Home depot will all break if heated to above critical, quenched in water, and hit by a hammer while in a vise.

Unless the shop has the steel labeled by formula or spec. ,any "found "steel is of an unknown alloy content, and the carbon level is only part of the story in if it will be usable for a knife.
I have found that the color codes on steel are nearly useless.
As far as gauging the carbon content by the "darkness" of the steel bar, that is just foolish. The surface color is a result of oxidation ,not carbon content.

A few weeks back, I was doing a demo. I made a tree spike plant hanger from 1/2" mild steel square stock. I drew out the end and made a spiral, drew out the other end into a spike, and twisted the center like a corkscrew. I bent the spike at 90 degrees, re-heated the bar, and stuck the spike end and the spiral end in the slack tub to cool it so I could hold the ends and bend the curve of the hanger on the bick. I forgot to re-heat the whole hanger after the shaping. I went to adjust a little twist and the spike snapped off in my hand.
 
Most likely all mild steel there. High carbon and tool steel will have color code, ends painted.

Get all you can haul home and use to build stuff, press, tables, trailer, etc...
 
okay, let me rephrase..... I can't get all I want as they have many trash bins with various metals that they dump into semi trailers and haul to recycling..

they've just given me the nod to take as I need not personal monetary gain...

If you seen my thread about grinder motors, well this is where I'm getting the metal to build my grinder.. amongst other things I'm sure...

Today I seen some really nice thick aluminum square tubing, who knows I may end up with an all aluminum grinder :D
 
Don Hanson III said:
Most likely all mild steel there. High carbon and tool steel will have color code, ends painted.

Get all you can haul home and use to build stuff, press, tables, trailer, etc...
Click to expand...

THat's realistic.

I would look for.

Tubing
Angle iron - Angle iron is awesome
I beam

pipe - 2 sizes that slip fit - think knife vise
Bench-and-swivel-knife-vises_MED.jpg
 
bladsmth said:
As far as gauging the carbon content by the "darkness" of the steel bar, that is just foolish. The surface color is a result of oxidation ,not carbon content.
Click to expand...

I was not saying darkness was an indicator of anything guaranteed. I personally notice that Rolled Sheet of the high 10XX variety, is darker than the 1010-1018. Could just be my imagination going wild, but then again I have been around the stuff my entire life, and can point out many, many things about steel/Alum/SST Sheet that others would never see.
 
Absolutely take a bunch home and build machines, workbenches, forges, etc. with it. I love finding good angle, beam, channel, tube, whatever. Plate steel is even more rare to find, but great when you do. Heck, save it up for a while and build a press.

When I worked on big jobsites, the one castoff steel I used for knives was tension cable. It was in all the concrete decks, for seismic code. About 3/4" round, as I recall seven thick wires around one. All I could ever find out about it was that it was normally made of "music wire" which is 1095. It welded easily, and made very good blades that would show hamon well. The watering was elongated and subtle, but pretty.

If you forge, look for square or round stock in 3/8" to 3/4" thickness. You can make tongs, and cool stuff like hooks and pokers and other hardware.
 
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