Steel choice for a chopper, 5160?

noseoil

noseoil

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Apr 24, 2013
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Being new to this world, I'm wondering about using 5160 for a chopper type of camp knife. I've read where it's plenty tough & takes a beating & is also fairly forgiving. I'm wanting to make something no larger than 18" over all (12" edge max), 1/4" thick at the spine & 2" wide at its widest dimension. I have a rough design worked out now, but I want to get some input on 5160 for this task. I'm not wanting to chop nails, bricks & concrete block, but wood.

As a follow-up question, is 58 about the right hardness for this type of steel & blade? I'll have to send it out for HT, so I can ask for whatever I want & be sure of getting close to that value. I'm planning on about 0.025" behind the edge for durability & having a fairly beefy profile behind the edge, with a good amount of mass for penetration, so it's not really a speed blade. Is going above the 58 mark a problem with 5160 & a larger blade like this? Will it take more than 58 & still be tough, or is that really the limit for this steel & blade type?

I know 3V would be a better choice in general, as would some other types, but since I'm very new to making blades, I don't want to spend that kind of money on a beginner's project, with the chance of screwing it up & making something ugly out a fine steel which deserves better. That can wait until later for me. Thanks for looking.
 
I you are new to making blades, then I would say 1084, especially if you plan to heat treat it yourself.
 
Nothing wrong with steels like 5160, 80CrV2, 8670, L6, 15N20 instead of high-zoot stuff like 3V.

For tempering, 58 would be fine for 5160. For 80CrV2 you probably don't want to temper it down that far. I'd take whatever you get at 400°F.

From what I've been reading, I don't know if I would ever temper any carbon steel above 400°F.
 
RX-79G said:
Nothing wrong with steels like 5160, 80CrV2, 8670, L6, 15N20 instead of high-zoot stuff like 3V.

For tempering, 58 would be fine for 5160. For 80CrV2 you probably don't want to temper it down that far. I'd take whatever you get at 400°F.

From what I've been reading, I don't know if I would ever temper any carbon steel above 400°F.
Click to expand...

Its not only depending on the tempering temp. The overall of how you prepare, austenitizing and quenching the steel are also very important.

I wish you should be less reading/theorizing and do more real world testing/using.
 
Luong: "X steel at 60rc with 0.025" BET; 20dps is very strong (via steel volume), so toughness probably be mostly an unused insurance."

If I'm making a blade with these dimensions, this weight & thickness (not really at all thin, at least in this case), is 60 a reasonable hardness to expect with both 1084 & 5160, and still have a good durable blade? I know edge holding would be much better at 60 with a chopper, but my concern is that the edge might end up too weak & brittle from bad impacts & possible twisting, due to an inexperienced user like me.

A better steel would take a much higher number easily, and have a thinner edge as well. Is that why you're saying that the edge geometry at 0.025 with a 20 degree bevel will be sufficient to hold the higher HT number and not suffer a failure with this type of a lesser steel? Sorry to belabor the point, but I'm trying to understand what you've said & why.

Thanks, tim
 
Hi Tim,

Since you will send it out for ht, use 80CrV2 (unless 5160 is on hand already). It's a better steel because finer grain and higher strength. Fine grain = higher strength+toughness.

A good balance of strength + toughness for chopper for Peters (and others good hters, except me) is where strength around: peak hardness - 5rc. Precipitate/ease high stressed areas of matrix - i.e. plate martensite; grain boundaries. Normal 5610 & 8670 peak hrc around 62-ish. While 1084 & 80CrV2 actually max hrc around 65-ish <= higher than that, could mean excess plate martensite, which is bad especially for chopper. So 59-61rc range for this 2 steels is about right.

0.025" BET + 20dps edge on a FFG 2" 1/4" 60rc 80CrV2 is very strong and very tough. Mis-hits and massive steering (due to knot or wild twisty grain) and super-hard woods and strong rebounce - all of these probably will ripple the edge & grind bevel just above edge shoulder. If you want to mitigate/minimize these remote chance of ripple, use 3/4 or 1/2 height sabre grind. That lower the CM (center of mass) and give edge shoulder wider lateral strength (more steel above it, that's all). Give up some penetration and gained some weight.

Higher hardness = higher level of working sharpness = (in general) less energy for same work load.

A 18 oz chopper with good profile & edge geometry will easily outperform 24 oz with thick edge geometry (~ 0.04" BET), extra applicable when cross-grain chopping seasoned woods.

Instead of having lingering doubts/second-guesses. Ask Peters Ht for 61rc 80CrV2. With naked blade (no handle), sharpened 20dps as sharp as you can. Light cross-grain chops 2x4, if fine, go to seasoned pine/oak -> pine heart wood -> now mis-hits ... until you get edge damage 1/64-1/32" deep. Pretty sure, it will be a rolled (aahh, exceeded elasticity and got plastic flowed). 58rc will roll much earlier than 61rc. If you get a nasty chip 1/32+", LOL sorry lousy ht. I recommended 60rc partially to covers a so so ht.

Here is my 65rc 0.325" thick W2, 0.016"BET, 15dps chops a small piece of African Blackwood. AB is extremely dense and hard, easily fracture/deform thin apex. A sharp 60rc 80CrV2 edge (same edge geometry) will roll if chop AB as video.
https://www.youtube.com/watch?v=-s_IVs7nyH4#t=10m52s


noseoil said:
Luong: "X steel at 60rc with 0.025" BET; 20dps is very strong (via steel volume), so toughness probably be mostly an unused insurance."

If I'm making a blade with these dimensions, this weight & thickness (not really at all thin, at least in this case), is 60 a reasonable hardness to expect with both 1084 & 5160, and still have a good durable blade? I know edge holding would be much better at 60 with a chopper, but my concern is that the edge might end up too weak & brittle from bad impacts & possible twisting, due to an inexperienced user like me.

A better steel would take a much higher number easily, and have a thinner edge as well. Is that why you're saying that the edge geometry at 0.025 with a 20 degree bevel will be sufficient to hold the higher HT number and not suffer a failure with this type of a lesser steel? Sorry to belabor the point, but I'm trying to understand what you've said & why.

Thanks, tim
Click to expand...
 
shqxk said:
Its not only depending on the tempering temp. The overall of how you prepare, austenitizing and quenching the steel are also very important.

I wish you should be less reading/theorizing and do more real world testing/using.
Click to expand...

What, exactly, is not only depending on temp?

Did you see the thread I put up in Blademaking? You could participate there.
 
If you're sending it to a pro for the proper HT for the steel & application, your options are limited only by your budget & creativity....I say use Elmax or CPM-20CV. It'd perform like a champ & the owner wouldn't have to worry about stuff like corrosion or sharpening so much. As long as it's used vs. wood and similar, it'll be more than tough enough, and it'll just be damn cool to have a chopper in a great stainless steel. My chopper/camp knife, while not quite the behemoth yours will be, is CPM-154, and I just love being able to use it for everything under the sun, wipe it off, and throw it back on my hip until the next use...with very minimal stropping/sharpening worries. And with all of my knives, I just prefer steels that can deliver the long lasting edges...they're not difficult to maintain & I just don't enjoy (yes, this means I'm not very good at it) "sharpening" anything...just my thoughts - best of luck on your chopper!!
 
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