Forging Steel from the 1800s, why did it do this?

[tsavickas36]

A friend of mine handed me a threaded rod that he had cut out of a building they were demoing out. He said the original build was from the 1800s. He went through 6 sawzall blades to get through the piece so it was obviously hard.

When I put it into the forge and started hammering it out to see if he could use it to make some knives it started cracking all over the place.

I am very limited in my knowledge of why this would happen since it was definitely hardened steel before.

Any direction you can provide would be great. Thanks in advance.

 

[Stacy E. Apelt - Bladesmith]

My guess is wrought iron. The "hardened" part may be not as much as he thought. It has to be worked HOT or it will mush apart. Too hot and it will also mush apart. It isn't good for blades.

Added - Just because the original building was from the3 1800's does not mean the bolt was. It could have been added during repairs 10 years ago.

 

[DevinT]

Wrought iron, probably low quality. Less refined than the good stuff.

Most had around 3% silica slag in it which is hard on saw blades. This material won’t harden.

It’s best to fold it and forge weld it to itself a few times to refine it. Then use it for cladding or guards, butt caps etc.

Hoss

 

[tsavickas36]

My guess is wrought iron. The "hardened" part may be not as much as he thought. It has to be worked HOT or it will mush apart. Too hot and it will also mush apart. It isn't good for blades.

Added - Just because the original building was from the3 1800's does not mean the bolt was. It could have been added during repairs 10 years ago.

Thanks for the input.

 

[tsavickas36]

Wrought iron, probably low quality. Less refined than the good stuff.

Most had around 3% silica slag in it which is hard on saw blades. This material won’t harden.

It’s best to fold it and forge weld it to itself a few times to refine it. Then use it for cladding or guards, butt caps etc.

Hoss

Thanks for the guidance. Ill pass that along

 

[Ken H>]

Hoss: Good info on the 3% silica as to why the rod acted like it was hard when sawing during demo, it wasn't the rod that was hard, but the silica slag that made it cut like it was hard.

Hoss, you're always such a good source of good info, and your son is following in your footsteps. The knive-making world is a better place for both of ya'll.

 

[weo]

Hoss: Good info on the 3% silica as to why the rod acted like it was hard when sawing during demo, it wasn't the rod that was hard, but the silica slag that made it cut like it was hard.

Hoss, you're always such a good source of good info, and your son is following in your footsteps. The knive-making world is a better place for both of ya'll.

Agreed! Just yesterday I had a question from one of the blacksmiths at the Makerspace where I run the metal shop and forge about some 1800's railroad track he got from a friend and wants to forge. If I hadn't been following this forum, I wouldn't have been able to warn him about the dangers to saw blades from silica slag potential and tell him to use a cut-off wheel instead of our bandsaw to cut forgeable chunks off this, which may have let to additional frustrations for me had this happened and me having to replace another saw blade due to member abuse.
Again, thanks!