Rucksack - Swiss Army knife

A shot of the Rucksack and Buck/Strider folder from the side :

and top :

Description

The Rucksack blades and tools are made out of proprietary stainless steel. The Rucksack is 4 3/8" long when closed. It has the usual red nylon handle slabs, with an ergonomic shaped handle. The various implements include : large locking blade, corkscrew, can opener with small screwdriver, cap lifter with screwdriver and wire stripper, reamer/punch, key-ring, tweezers, toothpick and wood saw. The main locking blade is 3.5" long, flat ground, 0.01" thick behind the bevel ground at 20 degrees per side.

Main blade

The initial edge sharpness on the main blade was low, it was significantly rolled and uneven. However the steel is easy to sharpen. The blade is made from thin stock, quite narrow and tapers to a thin edge so the cutting ability in general is very high in general and does especially well on binding materials like thick cardboard versus the common sabre ground on the thicker tactical folders. It works especially well as a paring knife in the kitchen.

edge retention

As a rough benchmark, the Rucksack was compared to a Henckels paring knife cutting 1/8" ridged cardboard slicing through the ridges. Both blades started out push shaving sharp with a finish produced by a 800 grit ceramic rod. The sharpness was determined by the number of strokes necessary to cut through a roll of fabric. Four cuts were made with the average used to determine the sharpness.

There was no significant difference noted between the two blades. Both blunted to about 50% after only cutting though 1040 cm of cardboard (about 35 feet). The edges were restored with a light steeling and 4-5 strokes on an 800 grit ceramic rod. Both were again push shaving sharp. The difference in blade stock (1.45 mm for the Henckels, 2.70 mm for the Rucksack) was easily noticed in the cutting. The slimmer Henckels offered much less resistance to the cardboard curing the slice.

The edge retention on used carpet was also found to be clearly behind harder and high wear steels. Slicing 3/8" manilla hemp, two inch draw, no backing board with a 22 degree micro bevel, the performance is interesting compared to the same work with other blades :

sharpening

The steel both machines and grinds very easily, it can be shaped with a file readily. The edge bevel is also very thin and thus it takes little work to reshape it to a user prefered bevel. It tends to form a very high push cutting sharpness readily.

Saw

The Rucksack saw has 12 tpi on a 8.5 centimeter edge. It is offset from the handle by about 4 degrees, slanted upward. The finish on the saw, as on the main blade, was very poor. The teeth actually had ridges of thin steel left exposed left over from the forming proces. After the first few strokes on some soft wood the additional metal broke off leaving the teeth nice and sharp. The saw was very aggressive in woods and cut well for its size. It could readily outperform other similar sized saws, for example, compared to the wood saw on the Leatherman Supertool on some scrap lumber the Rucksack saw had a clear advantage :

Similar amount of force was used with both saws, the teeth on the Supertool are actually sloped back towards the handle reducing the bite which allows it to run faster. Concerning saws and hunger, in general a saw should be just hungry enough so that it does not bind and allows fluid motion near max speed. Too hungry will requires more effort than can be provided and not hungry enough causes waste as the user will just top out a max speed. Excessive hunger is general worse as it can lead to frustration which can cause injury to the user or the saw.

In terms of ability to cut up wood, the saw is slow compared to chopping with a large knife. Comparing the saw felling some small trees to a Camp Tramp from Swamp Rat knife works. The seven inch blade easily was 40% faster than the saw. It was also readily outperformed by a Ratweiler cutting through various lumber. Larger pruning saws also have significantly more sawing ability due to the larger blades and more coarse tooth patterns. The Rucksack was readily outcut by a Felco .

Other tools / features

The tweezers are aligned nicely and can for example pull a hair from the the arm. The toothpick is nice but personally a pen would be preferred. The screwdrivers are well formed, squared not rounded. The wire stripper works ok making the process a little faster with a lower probability for breakage than without it. The can opener is also nice to have, but for most if not all cans, a decent steel blade will do it with little problems. The key ring is a very nice feature, as it gives an attachment point and allows placement of a lanyard. The laynard can aid in grip retention in extreme situations and aids in draw from the pocket.

Strength and durability

It is not difficult to damage the tools because of the low strength of the steel. The blade for have little ability to dig in even soft woods. Similar, while the screwdrivers are well formed they can deform on screws that are stuck.

Summary

The thin blade stock, thin edge and decently acute edge angle allow the main blade to have a high degree of cutting efficiency. The steel doesn't have a high degree of wear resistance and falls short slicing most abrasive media. It is designed more for corrosion resistance and push cutting.

In general the scope of work for the Rucksack is broad due to the complement of tools, which enhance the edge retention and cutting abilty by substituting for the main blade for cutting chores like the saw on woods, the can opener on metals, and the awl for poking, drilling or digging.

Comments

Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com. Comments can also be seen in the following ARCHIVED thread :

• Review : Swiss Army Knife - Rucksack