There is no single answer to what knife the US Army uses, because the Army doesn’t issue one blade to every soldier. What a soldier carries depends on their job, their unit, and their commander’s policies. Between the issued M9 bayonet, standard multi-tools, role-specific survival knives for pilots and EOD techs, and the personal blades soldiers buy on their own, the range is wider than most people expect.
The Standard Issued Bayonet
The bayonet is still the most recognizable knife the Army puts in a soldier’s hands. For decades the standard has been the M9, a multi-purpose blade built from 425 stainless steel with a 7.125-inch blade. It’s designed to double as a field tool. Mated with its scabbard, the blade and a wire-cutter plate form a functional wire cutter, though it isn’t meant for hardened metals or live electrical lines. Soldiers also use it as a general utility knife for prying and cutting cordage.
The OKC-3S bayonet was developed for the Marine Corps, but it turns up in Army conversations because some Army units carry it too. Ontario Knife Company makes it with a longer 8-inch blade and a partially serrated edge. It uses 1095 carbon steel with a phosphate coating, which holds a sharp edge extremely well but is prone to corrosion in humid or salty conditions. Anyone carrying one has to oil and maintain it regularly.
Bayonet charges are vanishingly rare in modern warfare. Soldiers still train with them, but the practical daily value of these knives is as heavy-duty field tools rather than close-combat weapons.
Multi-Tools for Everyday Field Work
If the bayonet is the iconic Army blade, the multi-tool is the practical one. The Gerber Multi-Plier 600 series is widely issued across the Army, typically in a Berry Amendment-compliant sheath made from domestic materials. It folds out into pliers, wire cutters, screwdrivers, and one or more blades. That covers most routine field tasks, from tightening loose screws on equipment to stripping wire.
Some specialties get purpose-built multi-tools. Explosive Ordnance Disposal technicians often carry the Leatherman MUT EOD, which packs 15 tools into a single device. Alongside pliers and a knife blade, it includes a mil-spec cap crimper, a C4 punch, a replaceable bronze carbon scraper, and fuse-wire cutters. A regular infantryman would never need any of that, but for someone disarming ordnance, each tool serves a specific function.
Specialty Knives for Specific Jobs
Some Army jobs call for knives that would be useless to most other soldiers. The clearest example is the Aircrew Survival Egress Knife, or ASEK, issued to Army aviators through the Air Warrior Program. Ontario Knife Company builds it with a 5-inch 1095 carbon steel blade, and every feature is aimed at one scenario: getting out of a damaged aircraft alive. The butt cap doubles as a hammer for smashing acrylic cockpit windows. Serrated sawteeth on the spine cut through aluminum aircraft skin. The sheath carries a separate strap cutter with a replaceable blade for slicing seatbelt webbing, along with a honing rod. The handle even has holes for lashing the knife to a stick to improvise a spear.
Combat medics, sappers, and other specialists carry gear tailored to their needs as well. Trauma shears aren’t knives, but they fill a similar role for medics who need to cut clothing away fast. Engineers and sappers lean toward heavier fixed-blade knives or hatchets that can handle prying and chopping tasks that would snap a folder.
Knives Soldiers Buy Themselves
Issued gear covers the basics. A huge number of soldiers supplement it with personally purchased blades, and this is where the real variety shows up.
The Ka-Bar is probably the most iconic personal knife in military circles. Originally made for the Marine Corps in World War II, surplus Ka-Bar knives found their way into Army hands during the Korean War and Vietnam. It hasn’t been standard Army issue for decades, but its reputation for durability keeps it popular as a personal purchase across all branches.1KA-BAR. KA-BAR History
Beyond the Ka-Bar, soldiers gravitate toward Benchmade, Spyderco, and various Gerber and Leatherman models. What these knives share is robust construction and blade steels that hold up under hard use. A soldier buying a personal knife wants something that can take abuse in dust, mud, and rain without failing at the worst possible moment. Comfortable grips, reliable locking mechanisms, and one-handed opening drive purchasing decisions more than brand loyalty.
Folding knives are the most common personal carry because they’re compact, legal on virtually every installation, and versatile enough for daily utility. Fixed-blade knives see more use in field environments where a soldier needs something that won’t fold under pressure.
What Soldiers Can Actually Carry On Post
The Army has no single service-wide knife policy setting a universal blade length or type. Installation commanders publish their own regulations, and while the patterns are similar, the specifics differ.
Fort Eisenhower’s rules, published in the Code of Federal Regulations, offer a representative example. Folding or fixed-blade knives with blades longer than three inches are prohibited in most areas of the installation, including living spaces, common areas, and privately owned vehicles.2eCFR. 32 CFR 552.127 – Prohibitions Soldiers legally authorized to possess a longer blade can carry one under limited conditions: the knife must be in a sheath or scabbard worn in a clearly visible manner, and commanders can authorize privately owned knives with blades over three inches for field duty specifically.3eCFR. 32 CFR 552.129 – Requirements for Carrying and Use The three-inch threshold for general carry is common across the Army, but soldiers should check with their provost marshal or chain of command before carrying anything larger than a small folder.
Certain categories are banned outright regardless of blade length. Knives with automatic openers, including switchblades, gravity knives, and stilettos, cannot be possessed, carried, concealed, transported, or stored on post. The exception is government-issued automatic knives authorized for duty.2eCFR. 32 CFR 552.127 – Prohibitions Manual folders with thumb studs or flipper tabs are generally fine within the length limit. Some tactical knives marketed to military buyers use assisted-opening mechanisms that sit close to the line, and when there’s any ambiguity, a plain manual folder is the safer choice. Concealed carry of any knife “designed for the purpose of offense and/or defense” is also restricted on most installations, and the rules around public gatherings on post are stricter still.