Vintage Shur Snap Automatic Switch Blade Knife

Vintage Shur Snap 4th generation switchblade with black synthetic scales made by the Colonial Knife Co of Providence, RI in the late 1950s. It measures 4 inches closed and 7.25 inches open. The tang is stamped SHUR SNAP over Colonial over PROV USA. The blade is in very good+ condition with factory edge and light wear. The scales are excellent as is the guard and pommel. The spring seems weak and will not lock up every time. Slight wobble when blade is locked open. Fine example with almost no surface oxidation.