BCMWn690

OK, third run and the numbers are getting stronger. Again, prepared on 800 grit wet/dry over a washboard, slightly burnished on plain paper. Beginning edge could pushcut newsprint at a 90 though with a bit of noise. Test is the standard 10lbs static load, 2" of travel.

This go around it hit 16lbs on the initial pressure cut. At around 140 passes it began to choke, but then recovered and ran to 213 before missing three in a row. Of the steels I've tested that makes it a very strong performer. It finished with 24 lbs on the pressure cut after failing the draw test.

So, the numbers are outside the 10-15 % I like to see from one test to another and outside the 20% I have set as a pass/fail as far as keeping the numbers from two runs. One more run will be needed to see where this steel/geometry falls.

Again, this steel has a bit reputation for stubborn burrs and was observed during sharpening. Did clean up nicely though and at the conclusion of this test there was zero evidence of rolled edge or burr remnants. No sign of edge damage. A strong result. I do not have a lot of experience with this steel but am beginning to grow in appreciation, at least for this example.

Martin
 
Alright, this was the last test.
Same criteria, 10 lb static load with 2" draw. Edge prepared on 800 grit wet/dry with mild paper burnishing to finish/deburr. Push cut numbers taken at start and finish, test media 3/8" manila rope, failure = three consecutive misses.

Start pressure cut = 15 lbs
Ran for 164 cuts
Final pressure cut = 21 lbs

Above average numbers from the previous test either due to exceptionally god sharpening job or more likely a thinner than average stretch of rope - I am running out of coils and so was unable to swap for a variety.

Very good performance on this test, edge showed no unusual wear defects or chipping etc.

Good stuff,
Martin
 
Martin - as usual, your posts are informative and well-covered <= I enjoyed & appreciated that!

Good sharpening and EI3K setup provide consistence numbers for testing edge wear resistant against rope. Matrix hardness (above 60rc) play a smaller role http://www.bladeforums.com/forums/s...ls-multiple-hardnesses-multiple-testers/page2

EI3K numbers at a quick glance (CV = approx heat treated carbide volume):
N690 63rc, 7cv% - 164 cuts
52100 63rc, 3.0cv% - 120
1095 64rc, 3.0cv% - 120
M2 65rc, 4.5cv% - 130
Cfv 61rc, 5.0cv% - 150 (average of 124+174)

HeavyHanded said:
Alright, this was the last test.
Same criteria, 10 lb static load with 2" draw. Edge prepared on 800 grit wet/dry with mild paper burnishing to finish/deburr. Push cut numbers taken at start and finish, test media 3/8" manila rope, failure = three consecutive misses.

Start pressure cut = 15 lbs
Ran for 164 cuts
Final pressure cut = 21 lbs

Above average numbers from the previous test either due to exceptionally god sharpening job or more likely a thinner than average stretch of rope - I am running out of coils and so was unable to swap for a variety.

Very good performance on this test, edge showed no unusual wear defects or chipping etc.

Good stuff,
Martin
Click to expand...
 
Just wanted to thank bluntcut and HeavyHanded for the thread. Very interesting stuff and lots of time and resources dedicated here.
 
bluntcut said:
Martin - as usual, your posts are informative and well-covered <= I enjoyed & appreciated that!

Good sharpening and EI3K setup provide consistence numbers for testing edge wear resistant against rope. Matrix hardness (above 60rc) play a smaller role http://www.bladeforums.com/forums/s...ls-multiple-hardnesses-multiple-testers/page2

EI3K numbers at a quick glance (CV = approx heat treated carbide volume):
N690 63rc, 7cv% - 164 cuts
52100 63rc, 3.0cv% - 120
1095 64rc, 3.0cv% - 120
M2 65rc, 4.5cv% - 130
Cfv 61rc, 5.0cv% - 150 (average of 124+174)
Click to expand...

Those numbers correlate amazingly close to the carbide volume - makes sense, but to see it arranged like that generates a bunch of food for thought.
 
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