Pronghorn by Ed Fowler

A shot of the Pronghorn by Ed Fowler:

The review consists of :

• specifications
• stock evaluations
• general work : food, field, miscellaneous
• edge retention
• ease of sharpening
• grip
• sheath
• overview
• comments and references

Specifications

This Pronghorn belongs to Gabe Newell is was bought new and unused. It was forged by Ed Fowler, an ABS Master Smith, out of 52100, a ball bearing steel, and heat treated using a triple quench to harden the edge. The guard is made from brass and the handle from sheep horn. The scabbard was crafted from thick leather with very tight stitching. The knife is neutral in balance and weighs 260 g. The Pronghorn is 0.215 inches at maximum through the choil, and has a slight distal taper towards the tip :

The knife is about an inch wide (2.4 cm), with a full convex grind with a very slight secondary edge bevel. The main grind measurements, taken about halfway out on the blade :

There is a secondary edge bevel, the knife is 0.010" thick behind the edge near the point, and trails beyond the visible through the choil. The bevel is uneven in width as well from side to side, and doesn't meet clearly at the tip which leaves it somewhat blunt.

Stock work

The initial sharpness was low. The edge on the Pronghorn was reflecting light for most of the length through the tip. Under magnification, the secondary edge bevel was clearly visible and was formed with a coarse abrasive. The major micro-teeth along the edge were about twenty microns deep. The edge would catch a few hairs on the left arm, none on the right indicating a rolled edge. There was little slicing ability on newsprint, would catch in places, no ability to push cut. Thread push cuts needed 190 g near the tip and up to 350 g near the choil, median 228 (32). The slicing performance on 1/4" poly was about 1.20 - 1.30 cm with a 1000 g load.

The Pronghorn could slice 3/8" hemp on a two inch draw requiring 17-19 lbs, 50 lbs on a push cut near the choil and 25-30 in the tip. The edge degraded rapidly in the tip, this would be expected as the asymmetric shaving ability and light reflection indicate a rolled edge.

The Pronghorn took 5.4 (5) cuts to make a point on basswood dowel.

As a chopping tool the performance was low as expected given the size. On small scrap woods it was used in both a two fingered partial grip around the end of the handle and a full grip around the handle. Chopping eventually progressed up to heavy swings from the shoulder and the Pronghorn had 36 (2) % of the ability of the Camp Tramp which translated to about 20 (2)% of the ability of the Wildlife Hatchet from Gransfors Bruks.

The Pronghorn's tip has a thick taper and the penetration is 600 (26) pages on a vertical stab into a phonebook. The tip was fairly blunt which lowered performance. It could not for example remove a splinter as it could not cut skin very well and it took the full weight of the knife for the tip to penetrate through a piece of photocopy paper held under tension. The knife was unable to dig in wood as noted below.

Food preperation

With the initial edge , while the thin edge profile was thin the lack of a high sharpness caused the Pronghorn to just mashed tomatoes. It could not cut through heavy bread crusts, nor effectively trim fats from poultry. The thick wedge shape also left it significantly behind a Japanese utility knife on most vegetables. Specifically the utility knife took 4 lbs to slice up a brocilli stalk and the Pronghorn 8 lbs . On larger vegetables the differences was greater still, 2 vs 6 lbs on an onion for example, 10-11 lbs vs 24-26 lbs on a turnip.

After sharpening the Pronghorn did well on the softer foods as they don't demand much from the geometry. It worked well on on meats, sectioning large cuts as well as taking apart various poultry for stocks, soups and baking. The tip profile worked well in removing the breasts and tendors. The tip was a little thick for joint work as it could not efficiently separate the joints, a much more slender tip like on the Model 10 was found to be much more efficient.

The corrosion resistance was low as expected for the steel. The Pronghorn took a patina quickly when exposed to acidic juices. The large guard also made use of a cutting board difficult and the handle also tended to get slippery when greased.

Wood working

For wood carving, the efficient edge profile makes for an efficient tool. However the large choil produces a significant leverage disadvantage unless a choked up grip is used and then there are various problems with ergonomics due to the very pronounced guard. The narrow profile and thus large spine to width ratio also lowers performance which puts it behind other blades with similar edge profiles such as an Opinel.

As a chopping tool, the Pronghown was ineffective mainly due to its size. With a partial grip around the end of the handle, the Pronghorn needed around fifteen chops to cut Alders about one and half inches thick. There were a lot of missed chops due to lack of control of the grip due to its shape, and the inherent instability of such a partial grip. It can be used with a baton to section thicker woods but the handle ergonomics were limiting and the blade length short for such work. The knife had little inherent splitting ability for similar reasons as it has low chopping ability. It was used to split some wood with a baton and the performance similar to a H1.

The tip was used to dig in a piece of clear pine of 2x6. The Pronghorn was unable to break the wood out on 1/4" and 1/2" of penetration mainly due to the thick convex nature of the tip grind which makes the knife pop out. On 3/4" of penetration, the knife could also not clear the wood and took a bend. The tip was bent 1/8" to the side for about 1" back. A Howling Rat was put 3/4" into the same wood and it easily broke the wood clear with little or no flex. Three holes were dug through the wood averaging around 30 stabs and side prys per hole. These were much harder and more dynamic leverages than with the Pronghorn.

In an attempt to straighten the tip, a piece of 2x2 was used as a mallet on the point on the Pronghorn, this bent the rest of the knife blade so it had an "S" shape which was unexpected. Again the Howling Rat was subjected to the same kinds of impacts but much more forceful ( I had to rest every few hits as the square edges on the 2x2 was doing a number on my hand), to no effect. The Howling Rat is fully hardened SR101, a steel variant of 52100. The Pronghorn was then put one inch into a 4x4 (into a crack), and leveraged it to straighen the tip. It bent easily, no significant amount of body weight was used. With continued effort, one hand, no bar, the knife readily went to 90 degrees and had little spring back, it took a large bend.

Edge retention

As a stock test of edge retention, the Pronghorn was used to slice 3/8" hemp rope on a plastic cutting board using a two inch draw. The cutting ability was determined by the amount of force used to cut the hemp and the sharpness measured by push cutting thread and slicing 1/4" poly. Four trials were ran on different rolls of hemp. The blade was fully sharpened each time finishing on a 12" 600 grit DMT rod set at 22 degrees and cleaned with two passes per side on canvas loaded with a chalk paste. The edge finish was checked under magnification to insure the edge was fully recut. After sharpening the Pronghorn could easily slice newsprint and push cut straight down, though was somewhat rough due to the relatively coarse DMT finish.

The hemp was also cut without a backing board :

The Pronghon compared well to various production knives. There was a complication with this cutting as the performance Pronghorn decreased with sharpening as if the edge was only very shallow hardened. This seems to agree with the very low strength shown in the tip work described in the above.

On used carpet, the Pronghorn was compared to several other custom and production knives with the sharpness tested peridically by slicing 1/4" poly. In short the Pronghorn performed poorly. A much longer run was also done comparing the the Pronghorn to a 52100 MEUK. Both were polished to a fine shaving edge with a 22 degree microbevel using a fine ceramic rod and would initially would slice 1/4" poly under a 1000 g load in under a centimeter. After two slices of two inches in length both blades fully reflected light and just scored the poly under 1000 grams of tension. After 161 cuts through the carpet the performance of the blades had stabilized. The edges were examined under magnification and showed huge gashes due to the grit in the carpet. The blades were steeled and the fine ceramic rod was used for multiple cycles of 10 passes per side - no effect. The blades were still unable to cut the 1/4" poly even under almost 5 lbs of force. Some rolling was present under mag but blunting was mainly induced by heavy wear. A 1000 grit AO waterstone (one inch wide) was used in small circular motions on the edges, using 100 circles per side. The progress of both blades was examined evenly during the honing. Neither seemed to have an advantage. A 4000 grit waterstone was used for two more sessions of 100 rotations each and both blades were free of any reflecting areas and very sharp.

In regards to wood work, after some initial light chopping the edge took a chip about 70 microns in depth. After this was sharpened out the edge didn't take similar damage in repeated work.

Ease of sharpening

After the blunting through the initial stock rope cutting, the Pronghorn was lightly stropped on 0.5 micron chromium/aluminum oxide loaded leather. Four passes per side increased the poly slicing ability from 1.0 to 0.75 centimeters. The thread cutting also took a large jump from 230 to 140 g. Checking the edge under magnification, the stropping raised the edge finish significantly.

During the initial sharpening for the hemp work the edge tended to burr readily on one side and when checked under magnification only the shoulder of the bevel was hit on the left side indicating the initial sharpening angle was more obtuse due to an asymettric primary grind. A 1000 grit waterstone was used to change the angle of the bevel to reduce it down to under 22 degrees per side.

The edge on the Pronghorn was easily filed indicating a low hardness.

Handle

The handle was designed for left handed use and is strongly asymmetric. The left facing side is significantly contoured, both through the thickness :

and height :

Immediately behind the second black spacer, in the region that has two dark vertical sections of horn (looks like a cartoon rabbit head), the handle has a significant hollow. On the other side, the basic profile is flat, with a large hollow :

The darkened region is hollowed out, this can be seen a little more clearly in the next picture :

The surface is smooth, no texturing. The overall fit of the sections is tight, though not totally flush in all areas. The first join is rough at the top and the second at the side. There is also a crack in the horn towards the rear of the grip about a half a centimeter in width which a finger nail can fit under and is abrasive to the touch. The handle was generally uncomfortable in all basic orientations and ironically least uncomfortable when the hollow was facing towards the palm, opposite of the intended use. Even though this presented an uncomfortable ridge to the hand the opposing side of the grip has a really sharp knob that is very abrasive in tight grips. After using the knife for an extend period of time the center swell the hand adapted. Positioning was also very critical, unless centered well it can be abrasive and uncomfortable in high pressure grips.

The guard was comfortable in contacts due to the curvature on the underside. In a choked up grip, where the index finger is in the choil and wraps around the guard, the top of the guard was however squarish and abrasive though still better than the Howing Rat in that grip as the Rat is "squarish" at the front of the handle. The choil is fully rounded and comfortable in extended use, in contrast to the Camp Tramp whose index finger cutout requires extensive sanding to obtain similar comfort. The choil is also well rounded however the guard is a little squarish along the top which prevents pressing down against it with the index finger. As the guard is also not flush with the blade there is excess pressure around the base of the thumb. Of course without the use of such a large choil area (sharpened area starts 3.5 cm infront of index finger) it would not be necessary to choke up on the blade to prevent a leverage disadvantage (which is 50 % for this blade in my hand). However the lack of a choil reduces blade length and ability for deep cuts. In the phonebook stabbing ergonomics and security were a problem due to the very specific shape not suiting a reverse grip and impacts off the guard were abrasive, as were contacts with the large center swell.

As for retention, with extended work multiple hot spots developed regardless of the grip position for both right and left handed grips. This irritation reduces security significantly as it forces the grip to relax. The handle was also greased using chicken fat and the Pronghorn was still able to cut ropes, cardboard, rubber tubing, various vegetation, and some soft woods (Alders). However a lot of pressure had to be exerted to keep the blade stable in hand during the cutting. Knives with inherently more secure handles such as the Howling Rat had lower fatigue rates due to not having to constantly squeeze so hard. In was also impossible to do even light impacts with the butt of the Pronghorn as the handle was not stable just forcefully pressing the end of the grip against a piece of wood and stabs would readily mash the index finger against the guard. A quick partial strength swing showed the grip retention to be too low to even keep the knife in hand during the swing let along during an impact. There is also no lanyard hole in the grip which would allow the use of a secondary retention system. The Howling Rat could be so snap chopped though a lanyard would want to be used to keep the necessary grip force low.

In regards to durablity, the horn is very resistant to abrasion, cuts, punctures and other such sharp contacts and obviously impacts, though the latter may be compromised by the nature of the tang and the joins. It is also likely very resistant to temperature extremes.

As a detail on the grip, due to the way that the grip drops down at a large angle to the blade, during the hemp cutting the rope could be cut on a draw by pushing back against the rear of the handle instead of hauling against the body of the grip. This has a large reduction to the fatigue rate and makes the cutting more efficient. It carries over into a lot of work as often pulling is more efficient than pushing.

Sheath

The sheath shows wear from sheathing and scratches from general abrasion. The edge is also frayed in places and has a couple of flaps and other loose bits of leather which could have been removed with some sanding or other finish work. The sheath is also opening at the bottom through one of the joins producing a visible gap about an inch long. It does hold the knife tight with no rattle or wobble of any kind. It takes five pounds to draw the blade. The edge is protected from the leather during the sheathing mainly via the guard which keeps the edge away from the side of the sheath, and sits on a ramp of leather inside the sheath. The ramp is left rough and shows significant fraying.

Overview

The Pronghorn has a similar profile to how David Boye grinds his drop point hunters and thus the cutting ability is near identical. The edge holding initially matched the performance of some production knives but rapidly degraded and fell behind even "lower end steels" and significantly below another forged 52100 knife. The very shallow hardening also made the knife much easier to bend so much so that it was weaker than much slimmer blades. The handle ergonomics were also found to be rather poor in most respects. However the sheath was solid in both retention and general use.

Comments and references

Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com or by posting in the following thread :

• Question for Cliff Stamp re: Ed Fowler's knives...

Supplementary threads :

• problems with hemp rope cutting as a test of edge retention
• Some carpet cutting with a couple of 52100 knives

There is also a page on this knife at Blade Gallery [webarchive cache].