as always there's tons of conflicting info out there. i'm making a square edge hardy tool mainly for tenons and lap joints from a piece of track. since there's really no way of knowing what the steel is for sure any thoughts on how to heat treat. after the time it's taking to forge a 4" section into what i need it would really suck if the thing cracks from being too brittle. 

any suggestions or a link would be great ...thanks

Treat it like what it is, nominally 1085 low alloy steel. Unless you picked up one of the yard rails that contains a higher content of vanadium and manganese, those are usually marked though.

Weygers', "Complete Modern Blacksmith" has quite a bit about hardening and tempering RR rail. no guarantees though.

If you want to be sure of how to heat treat your bottom tools buy something you know. I like 4140 but 1045 is a fine choice.

Frosty The Lucky.

point taken on steel for bottom tools  - definitely helps to know what you're working with but 1045 is so xxxx expensive, around me anyway, just bought  3ft of 2" round 1045 for 90 bucks.  

and thanks ...i've seen weygers book mentioned a bunch of times so ordered it last week. 

 

try this

 

Since you apparently have not noticed our subsections here I will relocate this post for you

I always thought RR track was already hardened already.

Work hardend where the wheele meets the rail

RR rail is induction hardened for the first few thousandths of an inch on the contact surface for wear resistance and friction reduction. The rest of the rail is in an almost normalized state relying on the shape of the rail for strength but MUST remain flexible to prevent work hardening.

The depth of hardness of the contact surface is maintained and deepened slightly by the work hardening of contact with car (rail car) tires. This accounts for wear but the shape of the rail "cap" prevents work hardening from penetrating more than a few thousandths.

Rail is stronger as is than if it was solid high alloy steel, it's real strength is in it's shape and how it's laid.

Frosty The Lucky.