Intelligent design advocate Michael Behe coined the term "irreducible complexity," which means "a single system composed of several well matched, interacting parts that contribute to the basic function of the system, wherein the removal of any one of the parts causes the system to effectively cease functioning."
It certainly describes this folder line by Glenn Klecker, award-winning knife and tool designer from Silverton, Oregon. He has named it after his son: Nathan's IRreducible complexity Knife, or NIRK™. There are just two well-thought out pieces, plus a blade pivot screw. The innovation is Glenn's use of a single sheet of stamped and folded stainless steel to serve as the folder frame, back spacer, spring and lock, resulting in a solid lockback folder.
The geometry of the cutout areas is critical, carefully calculated to provide just the right spring action when the rear of the spine is pressed. At the front of the frame, the lock tab mates with a notch in the blade to provide safe lockup. The tighter the grip on the handle, the tighter the lockup, making this an exceptionally safe design. It is very difficult, if not impossible, to accidentally release the lock, and it is very, very strong. When the blade is closed, the same lock tab ramps over a rounded detent to hold the blade in the closed position.
The new NIRK Novo models are slightly smaller with 2.75" sheeps foot blades, weight of only 2.5 ounces, a thumb stud for opening, and are available in Razor-Sharp and Combined Razor-Sharp & Triple-Point™ Serrated edge options. There you have it: simple, flat, almost indestructible folders. They are priced so you can afford several: one for the toolbox, one for the backpack, one for the truck, one for the boat, one for the survival kit. All models have stainless steel pocket/gear clips.