CRA or HR?

T

turkeyshooter

Active Member
I hope this isn't a dumb question, but I read where I should buy CRA for stock removal and HR for forging. Someone please explain the advantages and what exactly is the difference.
 
CRA is "Cold Rolled Annealed" where HR is "Hot Rolled". When I asked Matt Bailey for advice on the two, he told me that CRA 1095 would cut like butter. When I placed my order, I ordered HR due to the fact that it was in the size I wanted. I quickly learned that my bandsaw blade DID NOT like it one bit. It chewed up my blade pretty quick.

Hope this helps a bit.
 
I believe CRA does not have scale, and it is soft, so it's easier on belts/cutting. HR has scale, is not soft, but can be forged easily. I believe HR is cheaper usually.
 
I recently ordered some HR 1/4" x 3" x 72 and quickly found out this stuff is tough:eek::D

I think I will go the CRA route on the next order, specially for chopper steel. My BS works fine now with the new blade from Tracy, but still a beast to cut/grind.

I also noticed when drilling out holes in the tang there are hard spots that eat drills alive.cool 1

Dont get me wrong though, still loving the learning curves.
 
Nope, not dumb at all.

Guys are right, CRA stands for cold rolled annealed. You can anneal it your self by heating it up to critical and letting it cool slowly. Which I would do to either one if I was going to be cutting um with a consumer grade saw. Especially if it's one of the 10 series steels.

All annealing is not created equal. Different companies do a better job at it than others. Sometime it will be 18-20 Rockwell C scale and sometimes it may be as high as 38-40 Rc. Plenty hard enough to wreck even a pretty good saw. LOL

As they said, HR stands for hot rolled. And hot rolled is usually reserved for low carbon construction grade steel that's not subtable for making knives. That's because low carbon steel has a tendency to crack if it's cold formed. Dimensional steels like angle iron, I beam, plate steel, that sort of thing where welding, not machineability and hardness are the main concern it the most commonly cold drawn steels.

But there are exceptions to everything. ;~)

I would guess the recommendations you've read are based on the fact that cold rolled steel will be as much as 20% harder and stronger than hot rolled of the same grade according to the Machinery's Handbook. Especially on the outside. When smiths forge, they hammer in the additional toughness and they want to start with steel that's consistent all the way through. Just my guess at it.

JD,
 
Turkeyshooter,

Ive used both of these types of steel from admiral and here are my thoughts FWIW

For stock removal (what I've done thus far) stick with CRA steel ! The 1095 I've got cuts easily, accepts drilled holes with NO trouble, and grinds, as they say "like butter"

A 40 grit blaze will make CRA literally disappear ! Which is a good thing.

As mentioned, CRA= no scale.
can you grind off scale- yes
does that process eat belts- yes
Is this a PITA- yes
Does the use of abrasives outweigh the $ save by getting HR over CRA-IMO yes

Forging steel is a whole different process ! These are my thoughts as to why HR is good for forging and not for stock removal.

-due to the temps involved in forging the steel will have scale no matter what.

-working the steel at temps above critical negate the fact that it's not fully annealed from the mill.

-annealing is part of the process of making a forged knife before grinding on your forged blank so when you get to the stock removal part in forged construction your HR steel will now be annealed.

-Many stock removers will use precision ground steel and the grinder never even touches the flats or tang of the knife. This is a luxury not afforded to forgers. Even if forging from flatstock, the condition of the steel becuase of the heat involved will require that the entire blade be ground with the grinder so having a nice finish on the steel from the mill is no benefit to forgers but can be a HUGE time and abrasive saver for the stock remover.

I have annealed some HR 1080 from the mill before doing anything to it and it will greatly improve the working characteristics for cutting, drilling, and grinding but be prepared to do some major straightening of the steel before its workable. My pieces of around 18" came out of the anneal looking like a longbow. Fixable and useable but much more prep work than CRA before you even begin making a blade out of the steel.

These are my thought on this subject and do understand that I could be wrong about some of the forging aspects. I'm looking to get into forging in the comming year though so I've been studying up on the subject

-Josh
 
Wow,

Thanks for the info Josh! Lets just say I will try and stick with CRA from here on out. Just gotta burn up this tough HR 5160 first:D



Josh Dabney said:
Turkeyshooter,

Ive used both of these types of steel from admiral and here are my thoughts FWIW

For stock removal (what I've done thus far) stick with CRA steel ! The 1095 I've got cuts easily, accepts drilled holes with NO trouble, and grinds, as they say "like butter"

A 40 grit blaze will make CRA literally disappear ! Which is a good thing.

As mentioned, CRA= no scale.
can you grind off scale- yes
does that process eat belts- yes
Is this a PITA- yes
Does the use of abrasives outweigh the $ save by getting HR over CRA-IMO yes

Forging steel is a whole different process ! These are my thoughts as to why HR is good for forging and not for stock removal.

-due to the temps involved in forging the steel will have scale no matter what.

-working the steel at temps above critical negate the fact that it's not fully annealed from the mill.

-annealing is part of the process of making a forged knife before grinding on your forged blank so when you get to the stock removal part in forged construction your HR steel will now be annealed.

-Many stock removers will use precision ground steel and the grinder never even touches the flats or tang of the knife. This is a luxury not afforded to forgers. Even if forging from flatstock, the condition of the steel becuase of the heat involved will require that the entire blade be ground with the grinder so having a nice finish on the steel from the mill is no benefit to forgers but can be a HUGE time and abrasive saver for the stock remover.

I have annealed some HR 1080 from the mill before doing anything to it and it will greatly improve the working characteristics for cutting, drilling, and grinding but be prepared to do some major straightening of the steel before its workable. My pieces of around 18" came out of the anneal looking like a longbow. Fixable and useable but much more prep work than CRA before you even begin making a blade out of the steel.

These are my thought on this subject and do understand that I could be wrong about some of the forging aspects. I'm looking to get into forging in the comming year though so I've been studying up on the subject

-Josh
Click to expand...
 
best discussion on CRA, HRA and HR I've seen..

I've seen some thoughts on the stainless steels having less amalgamation separation in hot rolled. This shows up as mild banding or blotchy looking steel. I've seen steels like ats-34 have a blotchy appearance from what looks like a batch that didn't quite get mixed up enough. I quite using ats-34 for this reason, well that and the inclusions that kept popping up.
 
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It's not CRA, but I have a stick or tow of Aldo's 1084. I'd be more than happy to bring you a bar if you like next time I come down to see you. I may have some free time on Saturday.
 
Murph, I have 10 sticks 5'long of Admiral's 1084 HR as rolled.
I suppose I'm just too lazy to anneal it before using it.
You know how my time is and I have 12 more to get out ASAP and still working on that bistro.
I will probably just get into that 0-1PG and get them turned out.
But I thank you a bunch anyway.
Hay man- Have a HAPPY NEW YEAR--Jerry
 
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