BCMW ht 3V chopping tests

BluntCut MetalWorks

BluntCut MetalWorks

Knifemaker / Craftsman / Service Provider
Joined
Apr 28, 2012
Messages
3,462
BluntCut MetalWorks 20160603
CPM 3V, 65RC, 0.156" thick x 1.9" wide, 7.5" blade, 12.5" OAL
Edge thickness range: 0.014" to 0.025" (tested area ~0.02" thick)
Sharpened 15dps

I call this a confident builder test blade.

Chopped: 2x4 Douglas Fir, Seasoned pine & oak board, ended with 2 chops through a very thin metal broom handle.

While the 15 minutes video is slowly uploading...

What are your bets/speculations/:confused:
 
I haven't work with SpectrumWear before - https://www.alphaknifesupply.com/zdata-bladesteelC-SpecWear.htm
However I plan to make a 6.5" x 2" wide blade out of it. Target chopping hardness ~65rc
Also will make another 0.196" thick x 1.5" wide 7" aebl blade.. Target chopping hardness ~64rc

Any interests in seeing chop test videos? I don't want to bother BF public if what showing are deem as self promotion. Whilst my intention is showing there are much to learn about ht science.
 
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Luong,

If no one wants the video, pls email me. I want to see.
You've made D2 not brittle, what will it become of AEBL & 3V? :eek: :thumbup:
 
Thanks, Chris!

I will pre-ht grind those 2 blades and ht them today. A few days ago, I made a 64.5rc 5.5" aebl blade - in brain fart moment, tried baton through a seasoned knotty 2.5" dia olive branch. Started with a small chip but I kept hits harder and harder. Anyway, there experiments got activated ahead of time because I need 3V data. If aebl has cutting performs 80% of 3V, with its corrosion resistant & very inexpensive material cost - making it a winner for small & large knives.

Chris "Anagarika";16146287 said:
Luong,

If no one wants the video, pls email me. I want to see.
You've made D2 not brittle, what will it become of AEBL & 3V? :eek: :thumbup:
Click to expand...
 
That's a cool video of the thin-geometry 3V chopper at 65 Rc, especially when you're chopping knots and grain changes. I chop a lot of wood, and grain changes and hidden knots can do a lot of damage.

I didn't think 3V at that hardness would hold up, especially at that thinness. As you know, I've chipped my 3V chopper at 60 Rc just doing normal brushwacking.

When you got a small ripple in the edge when chopping through a metal handle, do you know what would make the steel ripple rather than chip? I think I was really impressed that an edge that thin just rippled slightly rather than chip when chopping metal because it shows a lot of toughness at high hardness.
 
At grain level - imagine a matrix as lego structure, where each piece = a grain. Structural cohesion/tensile depend lego block size; feet depth; offsetting and interconnecting. Higher cohesion would allow bend/flex more than structure with shallow feet depth and or cluster of highly aligned blocks (instead of interconnecting).

In the video, I mentioned - unlike a sub 60rc, once a high hrc edge is rippled, it can't be peen back. Thus there will be some loss in blade width/tall. Envision once a stack of lego blocks bent, which mean gaps occurred, so bend back stack will be slightly taller/longer. Well, in event of steel grain, bending back would rupture the plastic stretched boundaries (of course, implicitly martensite crystal also involved when grain boundaries cohesion is high... defer to talk about yet another wordy/blah topic).

Twindog said:
That's a cool video of the thin-geometry 3V chopper at 65 Rc, especially when you're chopping knots and grain changes. I chop a lot of wood, and grain changes and hidden knots can do a lot of damage.

I didn't think 3V at that hardness would hold up, especially at that thinness. As you know, I've chipped my 3V chopper at 60 Rc just doing normal brushwacking.

When you got a small ripple in the edge when chopping through a metal handle, do you know what would make the steel ripple rather than chip? I think I was really impressed that an edge that thin just rippled slightly rather than chip when chopping metal because it shows a lot of toughness at high hardness.
Click to expand...

edit to add:

My yt comment/reply

Instead of guessing - I went outside and:
Made 10 shattered chops through frozen beef rib bone. Straight down /perpendicular chops resulted in no or micro ripple. Repeat on same edge area with rippled = micro chips, since the bend has exceeded plastic zone. 20-30 degrees off 90* chops = big ripples and 1 chip to 0.008-0.01" cross section thick. From sound of some lateral chops, for sure I though/expect a large chip past edge shoulder - I am surprise at outcome.
I did tempered this blade down from 66+rc as-quenched. 3V 67rc is a highest AQ hrc I ever done. I plan to make a few small 3V knives with 66+rc. Certain will test 1 or 2 untempered 3V blades.
 
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I'm still amazed the 3V at 65 Rc will bend (ripple) before it chips. Hardness is a proxy for strength, which is resistance to permanent deformations, such as rolls, ripples and dents. Toughness, which is resistance to chipping and breaking, is usually higher at lower hardness levels.

3V is well known as an especially tough steel; even so, when it remains that tough (ripples before it chips) at that high hardness, the heat treat must be amazing, because that blade at that hardness is extremely strong.
 
Luong, have you considered sending an assortment of your knives to someone like Dan Keffeler or Gayle Bradley or another well known bladesports competitor for evaluation? It seems that that's where you're headed at some point.
 
It's the matrix - got it right, most steels will behave fairly similar. More/less group together in a narrow range in push/chop cutting. Strong matrix help keeping carbides in place (concrete & aggregate analogy) enabling better wear resistant when draw/pull cuttings.

3V is a 2.5-3% carbide volume steel, so toughness is a given. Most ht are mediocre because of failure in dealing with RA caused by extra alloy (cascade to extra strain/dislocation), a bit finer grain also amplify dislocation.

If you notice, most of my lately choppers have hardness around 65rc. Toughness in this context = energy load the matrix supports. Same old physics apply to all these steels... Otherwise, my 65rc D2 doesn't exists, right ;)

Twindog said:
I'm still amazed the 3V at 65 Rc will bend (ripple) before it chips. Hardness is a proxy for strength, which is resistance to permanent deformations, such as rolls, ripples and dents. Toughness, which is resistance to chipping and breaking, is usually higher at lower hardness levels.

3V is well known as an especially tough steel; even so, when it remains that tough (ripples before it chips) at that high hardness, the heat treat must be amazing, because that blade at that hardness is extremely strong.
Click to expand...

Thanks for the compliment. Dan & Gayle & others are well known in knife & bladesports community, they earned that with with a lot of works and years of present. My works & posts irked quite a few makers because of hard to swallow claims & anecdotal videos, so best not to spread myself thin.

bodog said:
Luong, have you considered sending an assortment of your knives to someone like Dan Keffeler or Gayle Bradley or another well known bladesports competitor for evaluation? It seems that that's where you're headed at some point.
Click to expand...
 
I got this done today

sZvLjld.jpg


I tried to pushed for a 65rc aebl, only got around 64.25rc (avg 4 reads) - so slightly greedy disappointed. At any rate, this new 0.196" thick aebl blade performed very well. After all the chopping, I cut up ~100ft of cardboard. Edge no longer slice phonebook w/o tearing.
 
Luong,

Thanks for updating, a bit OT but since it's AEBL & BCMW, I'd share a but too.

From my very limited test of AEBL 64HRC you sent me, slicing pizza tray single layer cardboard, the edge wear retention is similar to ZDP (E4) or M4(GB1), better than VG10 (Stretch). My parameter is whether the same amount (approx) of this and still shave my face, very unscientific, :rolleyes:

I also realized the ranking will depend on how the test parameters being defined. Slice cardboard until no longer slice phonebook paper, is different from no longer push cut phonebook paper, for example.

Your slogan should be "BCMW, where matrix matters"
;)
 
Thanks, Chris! I like your suggested slogan because actually reflect the blade core strength. Also appreciate feedback on the aebl paring knife. New aebl ht yields slightly higher toughness(mostly in impact load) than your version.

Chris "Anagarika";16149009 said:
Luong,

Thanks for updating, a bit OT but since it's AEBL & BCMW, I'd share a but too.

From my very limited test of AEBL 64HRC you sent me, slicing pizza tray single layer cardboard, the edge wear retention is similar to ZDP (E4) or M4(GB1), better than VG10 (Stretch). My parameter is whether the same amount (approx) of this and still shave my face, very unscientific, :rolleyes:

I also realized the ranking will depend on how the test parameters being defined. Slice cardboard until no longer slice phonebook paper, is different from no longer push cut phonebook paper, for example.

Your slogan should be "BCMW, where matrix matters"
;)
Click to expand...

My recent experiments with 3V; aebl; Spectrumwear are incidental stemmed from a need for data on 3V impact toughness at high hrc. Plus, I didn't want my dewar - full with LN2 - feel like a lonely evaporator:p I need at least 10 more experiments to fine tune ht params for high alloy steels. It's quite annoying not getting a 66rc peak-hrc for aebl. This ht process is much simpler compare to ht for low alloy high carbon steels.

edit to add: checked my ht log & toaster oven - look like multiple temperature spikes, so I am close to 66rc peak for aebl. With some tuning, a 66-66.25rc is possible.
 
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Howdy Luong,

Those bottom two profiles look familiar. ;)
Glad to see you're getting a baseline against 3v, seemingly everyone's favorite tough steel.

I told you my wife had comadered the zwear blade as her kitchen knife, right? She's now informed me it is traveling with us this year (we prepare alot of our meals when out). She doesn't want me using it anymore for hard (so-called abusive) tasks, that if I tore it up, I'd have to get her another one, so it mainly lives a pampered life on the kitchen counter now (I still sneak it out occasionally). She's also mentioned something about a whole set. :eek:

The 52100 & W2 blades are still fair game and get constant use for anything & everything, they will also travel with us, along with a k390 mule, 3v master hunter, and a home made M3.

All are holding up very well so far, much impressed, thanks! :thumbup:
 
Hi J,

Your great feedback and business are much appreciated! I am glad that 64rc zwear paring/light-util knife landed a comfy/easy life.

Heheh yup - one of the 2 profiles is striking similar to your design - doesn't it;) Oh there are more just like it are awaiting at the gate :D

jpm2 said:
Howdy Luong,

Those bottom two profiles look familiar. ;)
Glad to see you're getting a baseline against 3v, seemingly everyone's favorite tough steel.

I told you my wife had comadered the zwear blade as her kitchen knife, right? She's now informed me it is traveling with us this year (we prepare alot of our meals when out). She doesn't want me using it anymore for hard (so-called abusive) tasks, that if I tore it up, I'd have to get her another one, so it mainly lives a pampered life on the kitchen counter now (I still sneak it out occasionally). She's also mentioned something about a whole set. :eek:

The 52100 & W2 blades are still fair game and get constant use for anything & everything, they will also travel with us, along with a k390 mule, 3v master hunter, and a home made M3.

All are holding up very well so far, much impressed, thanks! :thumbup:
Click to expand...

Updates

Small 3V full tang above:
1) 66rc chipped when swing+wrist_flick at thin African Blackwood. Tempered down to 65rc - Passed.
2) Chop frozen beef rib bone - passed
3) Baton frozen beef rib bone - chip badly. Sheer baton strike - lost tip 0.8"L x 0.5"W, spine at break point ~0.075"
* this blade is too thin for this kind of abuse.

Spectrumwear tempered down to 65rc (didn't want edge to risk gross damage at 66rc)
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

52100 64.5rc ht on 20160605, 1/8" thick: 0.018" BET, 15dps, 2K waterstone finished edge
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

W2 66.5rc ht on 20160605, 1/8" thick: 0.03+" BET, 15dps
In spite of super thick edge however 2K finished apex is plenty sharp/thin
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

1084 stick tang, 66rc ht on 20160602, 1/8" thick: 0.02+" BET, 15dps
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

edit: re-stated 52100 & W2 hrc after grinded deeper into the blade (i.e. free of decarb). And added 1084
 
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bluntcut said:
Hi J,

Your great feedback and business are much appreciated! I am glad that 64rc zwear paring/light-util knife landed a comfy/easy life.

Heheh yup - one of the 2 profiles is striking similar to your design - doesn't it;) Oh there are more just like it are awaiting at the gate :D



Updates

Small 3V full tang above:
1) 66rc chipped when swing+wrist_flick at thin African Blackwood. Tempered down to 65rc - Passed.
2) Chop frozen beef rib bone - passed
3) Baton frozen beef rib bone - chip badly. Sheer baton strike - lost tip 0.8"L x 0.5"W, spine at break point ~0.075"
* this blade is too thin for this kind of abuse.

Spectrumwear tempered down to 65rc (didn't want edge to risk gross damage at 66rc)
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

52100 64.5rc ht on 20160605, 1/8" thick: 0.018" BET, 15dps, 2K waterstone finished edge
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

W2 66.5rc ht on 20160605, 1/8" thick: 0.03+" BET, 15dps
In spite of super thick edge however 2K finished apex is plenty sharp/thin
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

1084 stick tang, 66rc ht on 20160602, 1/8" thick: 0.02+" BET, 15dps
1) chop AB - passed
2) chop fbrb - passed
3) baton fbrb - passed

edit: re-stated 52100 & W2 hrc after grinded deeper into the blade (i.e. free of decarb). And added 1084
Click to expand...


Thanks for sharing Luong


great info

I learn alot from ya
 
Thanks Shawn! I've been following rour review threads, they are great!

DeadboxHero said:
Thanks for sharing Luong

great info

I learn alot from ya
Click to expand...

Updates

More ht done - this time aim for supporting high impact load and deal with extra mass thermal issue. Got 0.5rc short on 52100; however quite please with clean-abraded damage from aggregate rather than fracture type.

9JSoCyD.jpg
 
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