Zero point three one five inches. That is the number Vosteed built the Porcupine TiSlim around, and it is thinner than most people's phone. A 3.04-inch S90V blade in a Grade 5 titanium frame at that thickness, for $189, is a specific engineering claim rather than a styling exercise.
The build: 3.04-inch drop point in CPM-S90V, Grade 5 titanium handles CNC-machined and chamfered, a large aluminum backspacer for rigidity, a CNC-finished stainless liner integrated into the handle, Top Liner Lock, and 0.315 inches of overall handle thickness. Vosteed lists two versions, the A4815 at $189 and the A4814 at $179, both with S90V.
S90V at 3.04 inches is the most interesting part. It is a high-vanadium Crucible alloy, roughly 59-61 HRC in production, with edge retention that beats S35VN and MagnaCut on abrasive material and corrosion resistance that is merely adequate. It is also hard to sharpen: on a guided system with diamond stones it takes a while, and on a pull-through sharpener it will laugh at you. People who buy S90V usually know that. People who do not should buy the Raccoon TiSlim in 154CM instead and save the money.
The thinness has real consequences beyond pocket feel. A 0.315-inch handle means the lock bar travel is short and the springs are small, so a Top Liner Lock in this frame has less margin than the same lock in a 0.5-inch handle. Vosteed compensates with the aluminum backspacer, which is doing the structural work that a thicker titanium slab would normally do. Whether that holds up over years of flipping is the open question, and it is the reason to buy this knife from a dealer with a return policy rather than secondhand.
Compared with the Raccoon TiSlim A4516 at $145.99, the Porcupine costs forty-three dollars more for S90V instead of 154CM and a slightly longer blade. Compared with the standard Porcupine at $72.99 you are paying more than double for the titanium and the thin frame, and getting a knife that is meaningfully easier to carry. Compared with a $189 Benchmade or Spyderco, the steel is better on paper and the warranty is worse.
Verdict: buy it if you want the thinnest titanium folder with a genuinely high-end steel and you own diamond stones. Skip it if you want a knife you can touch up on a rod, because S90V is a commitment, not a convenience.
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