Do inclusions tell me anything about the metal?

[Scalebar]

Slowly converting an old coal shovel into new tools. This knife's stock removal, I've taken the metal down from 3mm to 1mm so I'm pretty certain these marks are inclusions. This is after heat treating and 800 grit clean up, Can I infer anything about the material from them? Other than it adds a little character... 

[JHCC]

Every one a possible failure point.

[Scalebar]

True but it won't stop me using mystery steel, probably wouldn't use this for aerospace applications though. With lapidary I got used to getting something almost complete then, plink.... 

I wonder what the faliure rate used to be in the days of bloomery metal 

[ThomasPowers]

The old books talk in detail about testing each piece of wrought iron you buy to see what it's like and so what it's good for.  They also may specify steel for use.  Swedish steel was know for it's quality for instance---generally because they were still charcoal smelting it for the high grade stuff.  The also had lower expectations in general; which is funny as they often used their steel much harder than modern people who are worried about issues in the 1% range while never using an item over 40%!

[Scalebar]

Thanks, I'm of sprung secateurs next - tin snip style spring , I'm figuring this would be bad choice for the spring?

[anvil]

Your shovel, if it's old, is most likely wrought iron. If modern, it's mild steel. Neither will make a spring

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[Scalebar]

It hardens well - snapped as I tightened the vice on it, nice fine grained grey-white fracture line 

[JHCC]

23 hours ago, anvil said:

Your shovel, if it's old, is most likely wrought iron. If modern, it's mild steel. Neither will make a spring

That's a little broad; a shovel could have been made from just about anything, depending on time, place, and (most importantly) what was available to the maker at the time. I have some steel straps (salvaged from a clothesline tree) that theoretically should be mild steel but are basically 1095.

[anvil]

Thanks, and you are correct. I should have said "modern shovels are mild or high carbon. 

Also, I'm actually winging it on old shovels as well. I'm assuming that older shovels were wrought due to price of other steels.

So scratch my last post. 

For what it's worth, and where my assumption came from, my grandfather was a coal miner '20's_'50's. I have one of his old shovels and have seen other old ones made in two or 3 pieces. There was the shovel body and one or two spade type connectors that rivited to the shovel and the other end made the socket for the handle. I assumed that the spade connector was a high carbon steel to strengthen the shovel, and join the shovel body to the handle, and when the shovel wore out, you could replace it.

[Scalebar]

This thing's all steel apart from the t bar - unless it had very long wooden shaft. The socket's welded onto a hefty shaft that's then riveted into another section. I figure I need to cut that into sections, slit it and flatten it. It all seems to spark well but I've not tried hardening it yet.