Edge Retention : Cardboard


Basic methodology :

In addition :

Cardboard details :

General steel classes

A few general notes :

In regards to the values :

means :

As a rough check, as long as the runs are changing the median by more than the standard deviations it is unlikely the result is stable (i.e. the true value).

Edge retention by Class on 1/8" cardboard at 15, 10 and 5% of optimal sharpness
Class # runs Sharpness 15% 10% 5%
cardboard cut (m)
I 29 70+ 0( 6) 1.4+0.0(0.2) 4.0+0.0(0.4) 21+ 0( 2)
II 27 90+ 0( 5) 3.1-0.0(0.3) 8.6+0.0(0.7) 43- 0( 3)
III 27 79- 1( 5) 4.0-0.1(0.5) 11.6-0.5(1.3) 65- 2( 7)

A summary table where the same steels are combined :

Edge retention on 1/8" cardboard at 15, 10 and 5% of optimal sharpness
Steel Hardness Sharpness # runs 15% 10% 5%
cardboard cut (m)
Class I
420J2 < =56 94+15(37) 21 1.0+0.1(0.1) 3.0+0.2(0.3) 18+ 2( 2)
L6 54-56 75+10(11) 5 1.6-0.1(0.4) 4.3-0.5(0.7) 21- 2( 3)
1084 54-56 83+ 4(14) 12 1.2-0.3(0.2) 3.5-0.5(0.4) 19- 2( 2)
440A 63- 2(24) 7 1.5-0.1(0.2) 3.9-0.1(0.4) 16- 1( 1)
12c27m 57-58 60- 5(14) 3 1.8+0.4(0.3) 4.9+0.9(0.7) 23+ 3( 3)
SM-100 59-60 75+ 0(18) 11 1.7+0.0(0.3) 4.3-0.2(0.6) 20+ 0( 3)
cKc-X 83+ 0(21) 10 1.4+0.1(0.2) 4.2+0.1(0.4) 25+ 1( 2)
Class II
50100-B, 52100 58-60 75- 8(16) 9 3.0+0.1(0.3) 8.1+0.1(0.8) 38- 2( 3)
8Cr13MoV 59-61 97+ 3(14) 12 2.7-0.2(0.4) 7.5-0.6(0.8) 39- 2( 4)
VG-10 58-60 83+ 0( 9) 31 3.9+0.1(0.3) 9.7+0.2(0.7) 42+ 1( 3)
AEB-L 60-62 107- 0(15) 24 4.0-0.1(0.4) 10.7-0.2(0.9) 53- 1( 4)
O1 58-62 79+ 0( 9) 16 2.7-0.2(0.3) 8.6-0.5(0.9) 57- 2( 5)
Class III
S30V 58-60 73+ 2(12) 25 3.0+0.1(0.3) 9.6+0.3(0.9) 57+ 1( 5)
Elmax 58-63 83+ 4(16) 21 3.8-0.1(0.5) 11.9-0.1(1.3) 74+ 2( 7)
1095 65-67 94+ 0(28) 6 6.5+0.7(1.0) 16.1+1.4(2.4) 70+ 4(10)
M4 60-64 83+ 0(15) 11 5.7+0.4(0.9) 17.5+1.8(2.4) 103+13(14)

The full table showing the results of each knife. Note the following data, note the color codes :

Edge retention on 1/8" cardboard at 15, 10 and 5% of optimal sharpness
Knife Steel Hardness Sharpness # runs 15% 10% 5% pps
cardboard cut (m)
Class I
Wiltshire Utility TiN 72-84 35+10(11) 2 0.7+0.0(0.2) 2.8-1.0(0.6) 21- 8( 5)
Ai De Chef - Roast 60+21(65) 5 0.8+0.0(0.1) 2.9+1.3(0.5) 20- 8( 4)
Endura Carving 43+20(11) 2 0.6+0.5(0.1) 2.2+1.2(0.5) 13+ 7( 3)
Galaxy Cleaver 38+ 1( 8) 3 1.0-0.0(0.1) 4.0+1.0(0.5) 20+ 2( 4)
Everyday Basics Santoku 54+ 8( 8) 2 1.2+1.0(0.1) 3.4+2.5(0.4) 17+ 8( 3)
CC Chef 420 J2 94+11(20) 4 1.4+0.3(0.1) 4.0+1.0(0.4) 20+ 3( 3)
J. Marttiini Fillet 420 J2 53-54 68- 3(24) 3 1.1+0.2(0.1) 4.0+1.0(0.5) 24+1( 4)
Point Guard 420J2 54-56 38+19(23) 2 0.1+0.0(0.1) 0.7+0.6(0.1) 7+ 5( 1)
MT 151 440A 50+ 0(11) 5 1.4+0.0(0.1) 3.6+0.0(0.3) 15+ 0( 2)
McCullen SM-100 59-60 60- 7( 8) 5 2.0-0.1(0.3) 5.3+0.3(0.8) 23+ 2( 4)
cKc SM-100 59-60 86+ 0(19) 6 1.3-0.1(0.1) 3.7-0.2(0.4) 17- 1( 2)
Douk Douk 1075 52-53 68+ 1( 8) 5 1.5+0.3(0.2) 4.7+ 0.6(0.5) 29+ 2( 4)
Bushman 1084 54 71- 4(10) 4 1.4-0.5(0.1) 4.4-1.1(0.4) 13- 4( 2)
small Peasant L6 54-56 HRC 66+ 1( 6) 5 1.4-0.1(0.2) 4.00.0(0.5) 20- 2( 3)
Svord 350B L6 54-56 HRC 75+23(21) 2 2.0-0.6(0.3) 5.0-1.0(0.8) 25- 1( 5)
Opinel 1084 54-56 100+15(30) 6 1.4-0.4(0.2) 4.0-1.0(0.6) 25- 8( 5)
Havalon Piranta 60+ 0(12) 1 2.4+0.0(0.3) 5.6+0.0(0.7) 20+ 0( 3)
Hudson Bay Camp Z50Cr14 52-54 68- 8( 8) 3 1.5-0.6(0.4) 4.5-1.5(0.6) 24- 8( 4)
Crater 420HC 55-59 HRC 83-11(12) 6 2.0-0.1(0.2) 5.0-0.0(0.6) 21- 1( 3)
PC Chef X55CrMoV14 71+11(15) 2 1.0+0.4(0.2) 3.2+0.6(0.6) 21- 2( 4)
MPU 440A 79+ 1(10) 2 1.9+0.2(0.3) 5.1+0.6(0.9) 24+ 3( 5)
cKc-X (t) cKc-X 79+ 4(18) 4 1.2+0.3(0.1) 4.2+1.0(0.5) 28+ 7( 4)
cKc-X cKc-X 88+ 0(17) 6 1.5+0.0(0.2) 4.3+0.0(0.5) 24+ 0( 4)
ESEE-3 1095 55-57 94+38(31) 3 2.4+1.0(0.5) 6.2+1.7(1.4) 28+ 2( 8)
Condor Bushbuddy 1075 56-58 58+ 2( 9) 3 1.0-0.3(0.1) 4.0-0.0(0.6) 26+ 3( 5)
Pacific Salt H1 57-58 68 + 0 ( 5) 3 1.4-0.3(0.2) 4.2- 1.3(0.7) 24-10( 5)
Junkyard Dog 13C26 55-57 94+16(20) 3 2.3+-.2(0.4) 5.8+0.1(1.5) 25+ 4( 4)
Mora #1260 1095 58-59 107+19(27) 5 1.8+0.2(0.2) 4.1+0.3(0.4) 16+1( 2)
Leuko 12C27m 57-58 94- 0(10) 1 1.7+0.0(0.4) 4.9+0.0(1.0) 26+ 0( 6)
Mora 2000 12C27m 57-58 54+ 4( 4) 2 2.0+0.7(0.2) 5.0+1.5(0.6) 21+ 5( 3)
Boker Rhino 12C27 83+ 8(24) 5 1.5+0.5(0.1) 5.0+1.0(0.5) 34+ 6( 5)
Class II
Uddo Puukko O1 58-59 75+ 0(11) 6 3.1-0.7(0.4) 9.3-1.0(1.2) 52+ 1( 8)
Twistmaster Carbon V 59 75- 0( 9) 4 2.6-0.0(0.3) 7.3-0.1(0.9) 37- 0( 5)
AK 47 AUS-8 59 54+14(13) 4 1.8+0.1(0.3) 6.5-0.2(1.0) 45- 2( 9)
Basic #10 INFI 58-60 75- 8(34) 4 3.5+0.8(0.5) 8.6+1.3(1.3) 36+ 1( 6)
Japanese Utility 1080 60 94+ 5(19) 4 3.7+1.0(0.9) 9.9+1.9(2.7) 48+ 3(16)
Great Eastern 1095 91- 3( 6) 6 2.8-0.4(0.5) 7.7+1.3(1.0) 40- 9( 6)
ZB 786 8Cr13MoV 91+ 8(14) 4 2.7+0.8(0.3) 7.3+2.2(0.6) 37+13( 5)
SRM 710 8Cr13MoV 117- 8(17) 6 2.8-0.7(0.4) 8.0-1.6(1.0) 44- 5( 7)
Blackjack Small 52100 88- 6(17) 2 3.6+0.7(0.5) 9.9+1.6(1.9) 50+ 5(12)
Ratweiler 52100 58-60 63-63(16) 3 4.0+0.4(0.6) 9.7+0.6(1.6) 37- 4( 7)
Meadowlark 8Cr13MoV 60-61 94+ 0(11) 4 2.7+0.4(0.3) 7.3+1.0(1.0) 36+ 4( 6)
K08 MBS-26 60-61 95+ 1( 9) 3 2.9+0.7(0.4) 7.9+1.5(1.1) 41+ 4( 7)
Serrata D-440C 63+ 0(10) 5 1.9-0.2(0.6) 4.9-0.6(0.5) 21+ 0( 2)
Fallkinven H1 VG-10 59 63+ 8(13) 3 3.6+0.8(0.6) 8.8+2.3(0.9) 35+ 8( 7)
Temperance 2 VG-10 58-60 73+ 5( 8) 6 4.2-0.1(0.6) 9.8+0.1(1.4) 37+ 2( 6)
Lum VG-10 58-60 100+ 6(17) 7 3.3-0.4(0.3) 8.7-1.0(0.8) 42- 4( 5)
Delica (wave) VG-10 58-60 94- 4( 9) 6 3.2-0.4(0.4) 7.8-1.0(1.0) 33- 4( 5)
Persian VG-10 58-60 79+23(16) 5 3.8-0.7(0.8) 10.9-1.1(1.3) 54+ 3( 8)
ErgoSlice N690 60 65+ 2(10) 6 3.6+0.2(0.6) 9.2+0.3(1.6) 40+ 1( 8)
Miyabi Chutoh VG-10 60 94- 3(11) 5 3.5+0.2(0.4) 9.6+1.1(0.9) 48+ 7( 7)
McCulleun Chef 14C28N 59-60 97+18(22) 4 3.5+0.4(0.5) 8.9+1.3(1.7) 56+ 9(12)
cKc Victorious AEBL 60 107- 4(29) 6 5.5+0.1(0.6) 13.5+0.8(1.5) 51+ 6( 8)
cKc mule O1 60 79+ 4(18) 4 3.8-0.8(0.7) 11.0-1.5(2.2) 58- 4(14)
cKc micro-hiker AEBL 61 75-28( 8) 7 2.6-0.0(0.2) 7.0+0.3(0.5) 34+ 3( 3)
cKc micro-hiker (A) AEBL 61-62 125+18(11) 6 5.7-0.4(0.8) 16.2-0.3(2.4) 83+ 6(16)
cKc micro-hiker (B) AEBL 61-62 111-14(17) 5 5.2-0.9(0.9) 13.5-2.4(2.0) 65-23(12)
cKc utility O1 62 79+ 4( 7) 6 2.0-0.1(0.3) 7.2-0.3(1.2) 52- 2(12)
cKc Chef AEBL 62 88+ 5(11) 3 3.6-0.9(0.5) 10.9-4.8(1.5) 64-25(11)
Class III
Gavko Spartan 3V 59-60 75+ 4(32) 3 4.0-1.0(1.0) 10.8-1.0(2.9) 52+ 7(17)
Gavko Flipper S35VN 59-60 81- 2(19) 4 3.9+0.7(0.8) 11.9+2.1(2.8) 70+22(20)
PXL SGPS 62 94+ 0(15) 5 4.8-0.2(0.4) 12.4-0.3(1.1) 56- 1( 6)
SureFire Delta S30V 58+ 3(17) 4 1.5+0.2(0.2) 5.5+ 0.8(0.9) 40+ 8( 9)
RSK S30V 58-60 84-10(29) 3 1.6+0.1(0.2) 4.7+ 0.1(0.6) 26- 1( 4)
Small Sebenza S30V 58-59 71-23(15) 4 4.1+0.7(0.5) 12.0+1.4(1.5) 66+ 2(10)
Paramilitary S30V 59-60 67+ 2( 8) 6 3.9+1.0(0.7) 11.5+2.2(2.3) 64+ 3(15)
Nilakka S30V 59-60 84- 4(29) 3 3.1+0.4(0.5) 10.3+1.8(1.7) 69+16(14)
South Fork S30V 60 97+11(22) 6 4.2-0.4(0.5) 13.7+0.4(2.1) 93+19(15)
Delica SuperBlue 62-63 97+ 3(13) 6 4.5+0.2(0.6) 12.3-0.5(1.8) 61-13(11)
Marcus Lin ATS-34 60++ 68-26(21) 3 5.4+0.8(0.9) 15.7+3.2(3.0) 83+22(19)
Safari Skinner D2 61-62 125+27(49) 4 6.0+0.4(1.1) 16.3-1.1(3.2) 85-32(20)
ZT 0561 Elmax 50+12( 8) 4 1.9-0.1 (0.2) 6.5- 0.5 (0.9) 41- 2( 7)
cKc ProtoType (Burnt) Elmax 60 58+ 3( 9) 5 2.7+0.6 (0.4) 7.9+1.1 (0.8) 41+ 2( 7)
cKc Slipjoint Elmax 60 100- 0(14) 6 5.8+1.0 (0.9) 18.0+1.7 (3.0) 112+12(23)
Johnson utility O1 63.5 93-10(23) 5 4.9-0.2(0.6) 15.1-0.4(1.5) 94- 0(12)
Marcus Lin 1095 60++ 125+25(24) 5 6.8+0.8(1.0) 16.3+1.2(3.3) 68+ 1(16)
Johnson Paring 1095 66 68+19(18) 2 12.2+5.0(2.5) 25.1+10.1(5.8) 84+33(22)
Pretium Elmax 62-63 97+ 3(28) 6 6.0-1.2(0.9) 18.3-2.4(3.2) 109- 4(23)
Richmond Artifex m390 61     65- 0( 9) 3 4.1+0.8(0.6) 11.8+0.6(1.0) 62- 9(12)
Delica ZDP-189 64-65 79+ 4(13) 6 6.2+0.5 (0.8) 19.5+2.2 (2.9) 120+20(22)
Air CPM-M4 62-64 83- 8(16) 4 6.1+1.8 (0.7) 18.8+3.0 (3.0) 110-15(25)
710 CPM-M4 62-64 86- 2(10) 6 5.5+1.0 (0.9) 16.7+3.5 (3.0) 97+23(22)
Modulator S110V 61-62 53+17(15) 3 5.0+2.3(0.8) 13.6+5.7(2.3) 62+27(13)
Coyote Meadow CPM-10V 62.5 73+ 8(11) 6 3.1+0.2(0.4) 11.1+0.5(1.5) 84+ 4(14)
OTK EDC k390V 64 37- 2( 2) 2 1.0+0.4(0.1) 2.9+1.4(1.7) 13+7( 9) 300+ 0(40)
Gavko CPM-S125V 63 54+ 0( 6) 7 3.2+0.1(0.4) 9.9+0.1(1.3) 55- 2( 9)
Farid 121 REX 68-70 52+ 4( 8) 6 1.6+0.2(0.2) 4.0+0.2(0.5) 17+ 3( 2)

Graphics on the individual steels in Class I :

and Class II :

and Class III :

Comments and references

Comments can be emailed to cliffstamp[REMOVE]@gmail.com or by posting to the following thread :

Most of the pictures in the above are in the edge retention album at PhotoBucket.


Last updated : 16/09/2013
Originally written: 11:29:2011
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