The knives, much like the pocket knives, use an internal spring mechanism to deploy the manual, partially open blade with direct force on the thumbstud. The very first spring assisted knife was named as the “strut-and-cut”. Unlike the switchblade knives, spring assisted knives are legal under the federal law; however, they cannot be carried to places where knives are generally prohibited. Moreover, it is advised that one must consult their local laws before carrying a knife around. Spring assisted knives are a great all-purpose knife and can be carried by anyone who needs a knife. These knives for sale can be used by sportsmen, policemen, civilians in the wilderness or even for self-defense. SwordsSwords has great quality blades with varying designs in the spring assisted knives section.