Photo from Benchmade.com
Benchmade Knives, based in Oregon makes some of the best automatic knives in the world. My favorite, the Benchmade 9100 AutoStryker was designed for military and law enforcement use and features a 3.7 inch 154CM Stainless Steel blade with a unique tanto spear point designed for exceptional piercing power. The thick blade spine absorbs shock and enhances tip strength. I've seen this blade punch through half an inch of kevlar. This knife has no cheap parts. The safety lever and trigger button are stainless steel, and the scales are solid cast aluminum with a thick black anodized finish. You can get the knife with a regular blade, or partially serrated. It's also available with black BK1 non-reflective blade coating for tactical applications. The AutoStryker isn't cheap, but I have seen it available on some websites for under $200.00. That's a lot of money for a pocket knife, but if I'm cutting myself out of fallen rigging on the deck of my sailboat in a storm, or freeing myself from tangled para-cord after catching my parachute in a tree, the best is worth it.
For those of you who aren't military or law enforcement, and don't live in a place where automatic knives are legal, Benchmade makes a number of great thumb-open tactical folders.