Over the course of Case’s long history, literally hundreds of different knife patterns have been created. To help our collectors identify the various patterns, we developed a unique numbering system. By learning the simple Case Dating System, you can easily determine the year a Case knife was manufactured. In , Case added dots beneath the “USA” on the tangs of all knives. As each new year passed, one dot was removed. Case XX Folding Knife Tang Stamp Dating Video Schrade Tang Stamps (AAPK-All About Pocket Knives) Schrade Knife Identification (johnstampercontracting.co.uk). S stamped in the base of the blade and what looks to be an H stamped into the tang any ideas on what this might be or what era it is from. Designs take shape as layers are folded in then welded together by forging; while creating an intricate design and strong blade. Also the blade is thick with aq case knives dating quard by the handle. Shop For Bulldog Brand Knives. The tang is at the end of the blade where the pin anchors it to the casing. Knives were stamped W. Identification and Value Guide Google Books.