What Aerospace Engineering Taught a New Generation of Knifemakers

When aerospace engineer Sal Glesser founded Spyderco in 1981, he introduced innovations the knife industry had never considered: a round hole in the blade for one-handed opening, a pocket clip for tip-up carry, and a focus on steel metallurgy that treated blade material as an engineering variable rather than a tradition to be preserved unchanged.

The most significant transfer from aerospace to knifemaking has been in steel selection. Alloys like CPM S30V, developed by Crucible Industries specifically for knife blades at the suggestion of custom maker Chris Reeve, use powder metallurgy achieving uniform distribution of vanadium carbides delivering both exceptional edge retention and practical toughness.

Powder metallurgy involves atomising molten steel into fine powder, then consolidating it under high temperature and pressure. This eliminates the carbide segregation plaguing conventionally cast steels and produces a homogeneous microstructure. The technology was originally developed for jet turbine components.

The same metallurgy has produced a naming problem worth knowing about. Bohler-Uddeholm's M390, Carpenter's CTS-204P and Crucible's CPM 20CV are effectively the same composition from three producers, so a knife advertised with any of the three offers the same material properties. The most interesting recent entry is CPM MagnaCut, designed by the metallurgist Larrin Thomas and released by Crucible in 2021, which reaches stainless corrosion resistance without the coarse chromium carbides that normally cost a steel its toughness.

Handle materials have benefited similarly. Carbon fibre, G10 fibreglass laminate, and titanium, all developed for aerospace applications, are now standard in premium knives. Their strength-to-weight ratios surpass natural handle materials, and their resistance to moisture and chemicals suits demanding environments.

Mechanism design has followed the same trajectory. Chris Reeve's Integral Lock, introduced on the Sebenza in 1987, turned a slab of the titanium handle into the lock face; Benchmade's Axis lock uses a spring-loaded bar across the tang; Cold Steel's Tri-Ad lock, designed by Andrew Demko, adds a stop pin that takes the shock off the lock face. Pivot choice matters too, since caged bearings feel smoother while phosphor bronze washers tolerate lateral load better and are easier to clean and rebuild.

Manufacturing tolerances have tightened dramatically. Where traditional knifemakers worked to tolerances of a few hundredths of an inch, modern CNC-produced knives achieve tolerances in thousandths. This precision enables smooth-action pivot systems where blade and handle must interface with bearing-like exactness.

Two practical consequences follow. First, heat treatment matters more than the alloy name, because the same M390 at fifty-eight and at sixty-one on the Rockwell scale behaves like two different knives, and a maker who will not state a target hardness is not really selling you a steel. Second, buy your abrasives with the blade. Vanadium carbides are harder than aluminium oxide, so conventional stones glaze and skate on these steels, and diamond or cubic boron nitride plates are not optional.

When selecting a modern knife, look beyond the blade steel to the complete engineering package: steel grade, heat treatment protocol, handle material, locking mechanism, and ergonomic design. The best contemporary knives integrate aerospace-derived innovations into a coherent system. Explore at https://www.spyderco.com