While both were made from VG-10, the F1 is slightly softer at 59 RC compared to the 60-62 RC of the Spyderco Bill Moran Featherweight . Both blades were sharpened to a fine shaving edge with a light secondary micro bevel from a fine 800 grit ceramic rod. The knives were used to cut up a used car mat and the number of slices required taken as a measure of sharpness :
| Model | First roll | Second roll | Third roll | Fourth roll | Fifth roll |
|---|---|---|---|---|---|
| F1 | 8 | 6 | 8 | 10 | 20 |
| Sypderco Bill Moran | 5 | 6 | 9 | 11 | 17 |
In short there is no significant difference seen. The Spyderco Bill Moran is slightly ahead at the end by a few percent, but the variance in cutting a roll is larger than the difference seen. This agrees with the last last comparison [ ref] which showed a similar small advantage to the SBM over the F1.
UPDATE : this type of comparison should be repeated several times with full sharpenings each time to ensure that the variance in the cutting is taken into account.
The downside to the slightly higher RC is that frequently this induces a loss in impact toughenss and ductility.
Both knives were chopped into a piece of pine 20 times, as well four assisted chops driving the blades in 3/8" deep. Further three pieces of lamp cord was chopped through, and then the blades were pulled the blades through a loop of the same wire five times. During the cutting the knives were twisted to generate shearing effects on the edges. The net effect of this was the blades were a little blunted but could still scrape hair.
One millimeter thick copper tubing was then chopped into ten times, the blades were twisted after the impacts. The SBM chipped resulting in a 1.5 millimeter long 0.3 millimeter deep gap. The F1 held up fine. The cutting was repeated with the F1 again with no damage.
A five millimeter mild steel rod was used to strike each blade ten times directly on the edge and then ten times on each side. The SBM did not handle this well and lost multiple pieces out of its edge. It fractured losing pieces out of the blade which resulted in multiple circular gaps from about 0.5 to one millimeter in diameter. The F1 was just slightly dented about 0.3 mm long and 0.2 mm deep. With some work with a steel the F1 was restored to being not significantly more than just blunted. The impacts were fairly hard and deeply cut into the rod and even bent it.
In short, the edge on the F1 is much more durable than on the SBM. Both have similar edge angles.
Each blade was stabbed about 1.0 cm deep into a piece of pine. The SBM's tip fractured easily on a pull and 1.0 cm stayed in the wood. The F1 had no problems and I increased the depth to 1.4 cm and it easily tore the wood apart.
UPDATE : the nature of the tip geometries is an important factor here. it would have been informative to have described both in detail.
The blade of the SBM was viced in wood about two cm back from the broken tip and flexed to 45 by hand which resulted in the tip being deflected 1.5 mm. The F1 was much stronger under heavier loads [ref].
Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com.
| Last updated : | Mon May 5 16:21:54 NDT 2003 |
| Origionally written : | Mon Sep 13 13:32:36 NDT 1999 |