MT17P - Mule Team Fixed Blade featuring K390

Ankerson said:
Not sure what you mean by tough.

K390 has a high compression strength and that helps with edge deformation when cutting, but it's not something I would use as a prybar or a screwdriver.
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sorry, i was worried that may be the case...bear with me while I try to ask my question in an intelligent enough manner:

i don't know if I am even educated enough in steels and metallurgy to ask this in the right way but when im asking about tough, im trying to understand the brittleness of this metal in relation to other steels that i may be more familiar with. is k390 similar to 10v or s90v in that i need to take care to avoid side loading while cutting for fear of significantly chipping out the edge? is it tough enough that I could use the mule to whittle away at hard woods and not need to worry about hurting the blade if my hand movements aren't just right?

maybe it would be more clear to ask you in terms of compression strength? when you say k390 has high compression strength, high compared to what? can you describe its compression strength in numerical values or percentages compared to s30v? to INFI? to 3v? to elmax? to k294?

I realize that in wear resistance and edge holding k390 is way high up the scale compared to any steels I've used before. I'm just trying to understand where its toughness (compression strength?) lies in comparison to other steels I may be more familiar with. forgive me if this is ridiculous to ask, but could k390 hypothetically be used for a chopping style blade or is it still too brittle for that, despite being significantly tougher than the other A11 class steels?

i realize we are talking about knives, cutting tools and not prybars or screw drivers, especially with how the mules are ground but experience has shown me that when i havent had the necessary tools, I have been able to confidently (mis?)use some of my knives for the unexpected task at hand whether it was prying or digging or similarly abusive "non-knife" tasks. I don't plan on using my mules in this way but am curious as to what this steel can handle...

hopefully this is clear enough - i really am just trying to understand as much as i can.

thanks for your time :)
 
shunsui said:
I think he means impact toughness measured by the Charpy C-Notch Impact Test. For example the Crucible 3V datasheet pdf shows Cru-Wear at 62 HRC having 30 foot pounds measured on the Charpy test, CPM M4 at 62HRC having 32 foot pounds, and CPM 3V at 62HRC has 40 foot pounds.

http://www.google.com/url?sa=t&rct=...M58wckg4qlCk4gbq8dp6qpA&bvm=bv.49784469,d.cGE
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yes exactly! that's what i'm trying to understand about this steel

thanks for the help with clearing that up :thumbup:
 
I cannot believe that I missed this one! :( they are all gone. Anyone have an extra for sale?
 
I received a MT17P in fine condition,thanks spyderco.
The grind is fine for starters,it is symmetrical and sharp.
The spydie hole is 8.6mm,the big holes in the handle are 10.15mm and the small handle holes are 4.85mm.
This seem a little larger than previous mules,should make handle fitting a little easier.
 
hookahhabib said:
sorry, i was worried that may be the case...bear with me while I try to ask my question in an intelligent enough manner:

i don't know if I am even educated enough in steels and metallurgy to ask this in the right way but when im asking about tough, im trying to understand the brittleness of this metal in relation to other steels that i may be more familiar with. is k390 similar to 10v or s90v in that i need to take care to avoid side loading while cutting for fear of significantly chipping out the edge? is it tough enough that I could use the mule to whittle away at hard woods and not need to worry about hurting the blade if my hand movements aren't just right?

maybe it would be more clear to ask you in terms of compression strength? when you say k390 has high compression strength, high compared to what? can you describe its compression strength in numerical values or percentages compared to s30v? to INFI? to 3v? to elmax? to k294?

I realize that in wear resistance and edge holding k390 is way high up the scale compared to any steels I've used before. I'm just trying to understand where its toughness (compression strength?) lies in comparison to other steels I may be more familiar with. forgive me if this is ridiculous to ask, but could k390 hypothetically be used for a chopping style blade or is it still too brittle for that, despite being significantly tougher than the other A11 class steels?

i realize we are talking about knives, cutting tools and not prybars or screw drivers, especially with how the mules are ground but experience has shown me that when i havent had the necessary tools, I have been able to confidently (mis?)use some of my knives for the unexpected task at hand whether it was prying or digging or similarly abusive "non-knife" tasks. I don't plan on using my mules in this way but am curious as to what this steel can handle...

hopefully this is clear enough - i really am just trying to understand as much as i can.

thanks for your time :)
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The edge isn't going to fall apart being that's is the normal .025" behind the edge that a lot of the other Spydercos tend to be so in short use it like you would a standard S30V Military.

Remember the blade is distal tapered so don't pry with it, but you don't have to treat it like a glass either, just use common since and enjoy the steel.
 
I looked on the bay out of morbid curiosity (already got mine), and someone has an MT17 for BIN at $300 :eek:
 
Yeah people on eBay are flipping these HARD. Glad I got one before the gouging could commence. Sorry DavidZ :(
 
That's one reason I'm glad the spyderco store has a 2 mule limit other wise a lot more of us would be paying inflated prices
 
^^^Indeed. I think courtesy and a tad bit of class would dictate at least waiting a few months before flipping a mule or any limited edition Spyderco. But who am I to say what others do with their property.
 
KNaB said:
Davidz has been taken care of ;)
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Thanks Mike - It is appreciated! :thumbup::) That is classy and first rate!! I cannot wait to try it - We blade forumites stick together - I hope to be able to return the good deed to you some day.
 
DavidZ said:
Thanks Mike - It is appreciated! :thumbup::) That is classy and first rate!! I cannot wait to try it - We blade forumites stick together - I hope to be able to return the good deed to you some day.
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Good show fellas!
 
Mine came on Friday but I was out of the office and won't be back until Tuesday. Really enjoying looking at the pics posted--thanks!

Just need to get some scales for her now.
 
In regards to toughness, I tried in vain to dig up some honest C-notch results on K390, but according to the data sheet using an un-notched bar, k390 is about 25% tougher than 10V/k294. The bar absorbed 44 joules of energy (34.5 ft/lbs) from the hammer before failure at 61HRc, which is pretty good, but hard to compare since this was not a C-notch test.

Extrapolating the percentage difference between 10V and k390 in the Bohler test, I would estimate a Charpy C-notch result of around 24-26 ft/lbs (at 61HRc, 1-2 points lower than the Mule). This would put it just below CPM-M4 at 63-64HRc or roughly equivalent to S30V at similar hardness.

From this deduction and my own initial impressions, I would agree with Ankerson and use it just as you would S30V. I am certainly not going to pamper mine.
 
Finally got my hands on mine today. Brought her home and instantly proceeded to put a Wicked Edge on her.

Couple initial thoughts. The knife I got has about a bend in it--at least 1/8". This is my first Mule Project. Has anyone else seen this? The other observation is that K390 is harder to reprofile than CPM M4! This steel is hard.
 
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