MT33 CPM REX 76 -First Impressions, Performance, and Testing Thread

[mtb]

@Steeltoez83
Could you share the sharpening experience please?
Would definitely be interested to see the video too! :)

[Steeltoez83]

@Steeltoez83
Could you share the sharpening experience please?
Would definitely be interested to see the video too! :)

I need to invest in some kind of tripod stand to record videos. Now im testing 24 other knives in conjunction with the mule. Now im not exactly fond of linking my videos for click bait purposes. And the true spirit of the mule team is to articulate what the performance and perspective actually is. Now in terms of performance, the factory edge hit the same performance level as the xhp on my native chief. The chief has had about 7 edges so its well past the fatigued edge stage. When I applied the same sharpening/testing protocols the edge leaped to 17 survival rounds. The closest competitor was the m4 pm2 with 11 rounds. When i placed the king neo edge on my mule I achieved 25 rounds of survival. I didnt restrain myself to testing protocols, just for fun to see what silicon carbide could do. S90V and maxamet after 6 edges hit around 10 rounds, the factory edge was hitting 8 on the mule. The mule is running circles around everything that im testing currently. In my last testing cycle it scored 36 when i incorporated stropping protocols. I usually journal my findings on my instagram, and get more detailed on there what im doing and what im finding. I was using a 220 grit aluminum oxide sanding sponge as my test strop. I coated that in 4 micron stroppy stuff compound. The strop had 480 passes before I even touched the mule. H1 on the same test got 18 rounds, the mule got 36. I used the spyderco cbn benchstone for the last round of testing, however most forum folk use the sharpmaker. Ive only used diamond, cbn, and silicon carbide to sharpen this steel. All harder abrasives then what I predict others will use. Now It seems it takes a bit more work to set a burr than most other knives, so I predict more ppl will have issues if they dont understand what they are doing. I havent tested a pure ceramic sharpening progression, but I would guess the performance would plummet. I dont know how it compares to the common cardboard testing, but it seems very resilient to edge deformation in the testing i do. Id like to see this steel on the military bcuz the maxamet military seems like a pipe dream at this point. It takes a edge very similar to maxamet, for a frame of reference. Im personally curious what others notice in terms of performance and sharpening. Im really a big fan of this stuff, and would buy another offering if available.

[Ramonade]

I just wonder, what is a survival round ?

[Steeltoez83]

I use 1 inch cutting edge. The knife goes thru 30 inches of gravel/sand/potting soil. I lay builder paper on top and make 2 cuts 15 inches each. Clean the blade with my fingers, no stropping allowed. Test sharpness on index card for the ability to cut. Flat apex folds the card.

[Ramonade]

I use 1 inch cutting edge. The knife goes thru 30 inches of gravel/sand/potting soil. I lay builder paper on top and make 2 cuts 15 inches each. Clean the blade with my fingers, no stropping allowed. Test sharpness on index card for the ability to cut. Flat apex folds the card.

Ok, so you're not messing around when you are talking about survival. You are seeking for the edge that can not only cut the car, but the road in half too !

[mtb]

Thanks for taking the time for such detailed write up!
Sounds like it will take a loooooong time before I can discover its true potential with my usage pattern, but it's worth the effort.

I need to invest in some kind of tripod stand to record videos. Now im testing 24 other knives in conjunction with the mule. Now im not exactly fond of linking my videos for click bait purposes. And the true spirit of the mule team is to articulate what the performance and perspective actually is. Now in terms of performance, the factory edge hit the same performance level as the xhp on my native chief. The chief has had about 7 edges so its well past the fatigued edge stage. When I applied the same sharpening/testing protocols the edge leaped to 17 survival rounds. The closest competitor was the m4 pm2 with 11 rounds. When i placed the king neo edge on my mule I achieved 25 rounds of survival. I didnt restrain myself to testing protocols, just for fun to see what silicon carbide could do. S90V and maxamet after 6 edges hit around 10 rounds, the factory edge was hitting 8 on the mule. The mule is running circles around everything that im testing currently. In my last testing cycle it scored 36 when i incorporated stropping protocols. I usually journal my findings on my instagram, and get more detailed on there what im doing and what im finding. I was using a 220 grit aluminum oxide sanding sponge as my test strop. I coated that in 4 micron stroppy stuff compound. The strop had 480 passes before I even touched the mule. H1 on the same test got 18 rounds, the mule got 36. I used the spyderco cbn benchstone for the last round of testing, however most forum folk use the sharpmaker. Ive only used diamond, cbn, and silicon carbide to sharpen this steel. All harder abrasives then what I predict others will use. Now It seems it takes a bit more work to set a burr than most other knives, so I predict more ppl will have issues if they dont understand what they are doing. I havent tested a pure ceramic sharpening progression, but I would guess the performance would plummet. I dont know how it compares to the common cardboard testing, but it seems very resilient to edge deformation in the testing i do. Id like to see this steel on the military bcuz the maxamet military seems like a pipe dream at this point. It takes a edge very similar to maxamet, for a frame of reference. Im personally curious what others notice in terms of performance and sharpening. Im really a big fan of this stuff, and would buy another offering if available.

I use 1 inch cutting edge. The knife goes thru 30 inches of gravel/sand/potting soil. I lay builder paper on top and make 2 cuts 15 inches each. Clean the blade with my fingers, no stropping allowed. Test sharpness on index card for the ability to cut. Flat apex folds the card.

[Steeltoez83]

I wanted to make my testing different from everyone else. And I wanted to make a high and low volume versions to see where steels excel at. Ive done rope cut testing before and I got burned out on that. I dont think ppl cut rope for a living, and this test is to replicate not hard use but harder use without lateral stresses. The apex becomes more durable if i raise the angle, but it loses the sharpness to go longer rounds. Its not perfect, but its something I was doing before my mules arrived. Goal was to have edges dull within 20-25 cuts. The higher volume testing is not been determined yet, but id want 50-75 cuts so i can do 2-3 knives a day. I figured im testing 20 other spydies so its a good frame of reference. Being under the umbrella of other spyderco products, and articulated on a spyderco forum. Mule performance feedback is a lackluster endeavor, and id like to input what I can. Perhaps inspire others to articulate their perspectives on a project that banked on us the community to produce feedback. I am sending out a rex76 mule to get tested for hardness this week. Im hoping triple b keeps it for a few months and puts it thru his own line of testing. And gives direct feedback to Sal on whatever he finds.

[mtb]

I wanted to make my testing different from everyone else. And I wanted to make a high and low volume versions to see where steels excel at. Ive done rope cut testing before and I got burned out on that. I dont think ppl cut rope for a living, and this test is to replicate not hard use but harder use without lateral stresses. The apex becomes more durable if i raise the angle, but it loses the sharpness to go longer rounds. Its not perfect, but its something I was doing before my mules arrived. Goal was to have edges dull within 20-25 cuts. The higher volume testing is not been determined yet, but id want 50-75 cuts so i can do 2-3 knives a day. I figured im testing 20 other spydies so its a good frame of reference. Being under the umbrella of other spyderco products, and articulated on a spyderco forum. Mule performance feedback is a lackluster endeavor, and id like to input what I can. Perhaps inspire others to articulate their perspectives on a project that banked on us the community to produce feedback. I am sending out a rex76 mule to get tested for hardness this week. Im hoping triple b keeps it for a few months and puts it thru his own line of testing. And gives direct feedback to Sal on whatever he finds.

Kudos to you, and please keep these great information coming!

[Steeltoez83]

I sent out a bunch of knives to triple b and i havent received any specific information in regards to his findings. To be fair I sent him 6 knives for him to use and enjoy. I am sure he can forward his findings directly to Sal. His 2 cents carry more weight than mine. Now Ive know Shawn for years, in fact I might be the first he told me about his collab, and i got to view the prototype before anyone else. There was a misunderstanding about the urban run in AEB-L so i sent mine to him for evaluation. His name was associated with that batch heat treat but mine was rockwell tested at 58.3. In private discussion he agreed to check out both my rex 76 mules as well. I threw in my 10V pm2 so he can directly compare his 15V heat treat to that. I know Shawns focus is on his own knives so he has to focus on business priorities over spyderco collections. I threw in my s110v ukpk which was hardness tested at 62.6 if i remember correctly. And i also threw in my sage 3 so Shawn has 6 of my spydies. As a knife maker I think he has a better grasp of evaluating heat treat and geometry just from experience with trial and error. Just a matter of time before I can report anything.

[mtb]

I sent out a bunch of knives to triple b and i havent received any specific information in regards to his findings. To be fair I sent him 6 knives for him to use and enjoy. I am sure he can forward his findings directly to Sal. His 2 cents carry more weight than mine. Now Ive know Shawn for years, in fact I might be the first he told me about his collab, and i got to view the prototype before anyone else. There was a misunderstanding about the urban run in AEB-L so i sent mine to him for evaluation. His name was associated with that batch heat treat but mine was rockwell tested at 58.3. In private discussion he agreed to check out both my rex 76 mules as well. I threw in my 10V pm2 so he can directly compare his 15V heat treat to that. I know Shawns focus is on his own knives so he has to focus on business priorities over spyderco collections. I threw in my s110v ukpk which was hardness tested at 62.6 if i remember correctly. And i also threw in my sage 3 so Shawn has 6 of my spydies. As a knife maker I think he has a better grasp of evaluating heat treat and geometry just from experience with trial and error. Just a matter of time before I can report anything.

Do keep us posted!

[legOFwhat?]

Spent a few hours with this mule this weekend, broke down a box big enough for me to fit in, to the point where the friction made the blade nearly too hot to touch. Whittled around on some cedar, then limbed a few trees to clear our walking path. I figured the impact of chopping through the little libs would do a little damage, because I even had to do a little batoning to get through some of the harder limbs.

At 17°it isn't the best shaver. I wanted a stronger edge after chipping on brass rods. 17°seemed to hold up against the same abuse and now after cleaning up all the tree goop, I was surprised to still cleanly slice through copy paper. I think I'll lower the edge back down to 15° or so and call it good.

[aprivetera]

Here are my initial impressions of (and a little advice needed for) the Rex 76 mule compared to previous experience with SRS13/SUS405 mule. Certainly feels very sharp and holds that sharpness well, definitely stays sharper than the san mai mule. The blade seems not as polished or impressive looking when compared to the Japanese work of art, but it offers better performance.

So far it's been on a quick backpacking trip, easily sliced up a large cardboard box into small pieces for a Halloween costume, carved three big pumpkins and served plenty of time in the kitchen. Rex 76 definitely feels easier when cutting through tougher materials compared to SRS13/SUS405.

The big drawback is the non-stainless nature of the steel. It's already showing some small spots of corrosion on the handle since it's just wrapped with some paracord. The SUS405 has definitely outperformed in that category.

G10 handles might be necessary on the non-stainless steels for the long haul. Wondering if they need any special backing between the scales and handle to resist corrosion even further. Would appreciate other experiences and any tips from those more familiar with non-stainless, non-treated steels like these.

[Ramonade]

I can say that i saw rust even on the tang of the RWL34 Mule when it was rocking the G10 scales for a while.

I'm in the process of making a definitive handle for the Rex76 but in the meanwhile, i did put a coat of Froglube paste between the G10 scales and the tang of the Rex76.

As for the finish of the blase compared to the SRS13 Mule. My feeling was the opposite

[standy99]

G10 handles might be necessary on the non-stainless steels for the long haul. Wondering if they need any special backing between the scales and handle to resist corrosion even further. Would appreciate other experiences and any tips from those more familiar with non-stainless, non-treated steels like these.

Thin strip of felt (buy at any craft, fabric store) soaked with mineral oil placed under the scales between the scale and steel will prolong the need to take scales off for checking.

I went to putting on permanent (epoxy) scales on most mules I own due to the constant corrosion when I removed scales. Even steels I didn’t think would have issues. (Use the above felt trick for newer mules I use before I get to putting scales on)

[mtb]

Inspired by the performance of K390 Endura/Police @ 13 dps, I took the REX76 Mule Team to 13 dps too.
While it works extremely well at home, I wanted to see how good it works outside.
I have the wrong scale for this task, but it performs well... maybe not as tough as the K390s @ 13 dps

[Steeltoez83]

Both my rex76 mules tested at 69.3 hrc. Triple b Shawn uses 10 measurements and averages the results.

[tcarltonw]

Both my rex76 mules tested at 69.3 hrc. Triple b Shawn uses 10 measurements and averages the results.

Good stuff, thank you for doing that and taking the time to share. Theres also no question of the accuracy of Shawn's numbers. I think Fullscaler posted recently if anyone had gotten any numbers back so I imagine he'll be happy to hear. Out of curiosity, what did your other blades read at? Appreciate it man.

[Steeltoez83]

Both my rex76 mules tested at 69.3 hrc. Triple b Shawn uses 10 measurements and averages the results.

Good stuff, thank you for doing that and taking the time to share. Theres also no question of the accuracy of Shawn's numbers. I think Fullscaler posted recently if anyone had gotten any numbers back so I imagine he'll be happy to hear. Out of curiosity, what did your other blades read at? Appreciate it man.

Shawn only provided me with the hardness of the mules and some factory edge bess test results. Not sure if he put any mileage on anything I gave him. He did have 15V to enjoy after all.

[tcarltonw]

Both my rex76 mules tested at 69.3 hrc. Triple b Shawn uses 10 measurements and averages the results.

Good stuff, thank you for doing that and taking the time to share. Theres also no question of the accuracy of Shawn's numbers. I think Fullscaler posted recently if anyone had gotten any numbers back so I imagine he'll be happy to hear. Out of curiosity, what did your other blades read at? Appreciate it man.

Shawn only provided me with the hardness of the mules and some factory edge bess test results. Not sure if he put any mileage on anything I gave him. He did have 15V to enjoy after all.

Yeah that's definitely understandable. A man and his craft.

[tcarltonw]

So I recently sharpened the 76 mule that I got back from Cerakote and have to say it was easier to sharpen than I expected. I had planned ahead of time to go with 17 dps & after checking the angles of each side it wasn't too far off. One side was ~ 16° for a majority of the edge with a slight increase as it approached the plunge line & tip. The other side was 18° with multiple 1° changes and 2 to 2.5 ° increases near the plunge and tip. So while it wasn't uniform it wasn't too far off from where I wanted to be without having to do a full reprofile. I used a kme with diamond stones and went 100, 140, 300, 600, 1500. Think I'm going to run with it as is for now, touch it up later, then put it through a strop progression for comparison. Also, I've been up since 3am so hopefully that made sense