W.R. Case and Sons Cutlery is among the most well-known and well-respected creators of pocket knives in North America.

W.R. Case History
Four Case brothers, including William Russell Case, started out crafting and selling knives back in 1889. Initially located in New York, the brothers relocated to Pennsylvania in the early 1900's. Nowadays, from the company's home base in Bradford, Pennsylvania, the Case Family continues to build a company renowned for its rich history of making the best U.S.-made pocket knives.

Case XX Knives
Case uses the "XX" mark on most of their blades to indicate its commitment to quality. The genesis of this term stems from the two-time forging process utilized by Case blademakers.

When the knife blade ended the first forging process, it was marked with a single 'X'. At the end of the second process, it was branded with a final 'X'. These days, the "XX" mark has become a symbol of the company's long-standing commitment to quality and craftsmanship.

Case Pocket Knives
These days, Case's offering has nearly 100 unique knife models including several that have been made for many years. Recent blades in the line are the Cheetah, the SlimLock and many others. Case Pocket Knives are owned by outdoorsmen, collectors and other knife buffs.

Blades
Different types of steel are utilized in Case blades: Chrome Vanadium, Tru-Sharp Stainless Steel, or the premium ATS-34. Chrome Vanadium is the softest and easiest to re-sharpen, while the ATS-34 requires additional re-sharpening skill. Chrome Vanadium requires a periodic treatment with oil to resist corrosion. The Tru-Sharp steel is a great tradeoff on most aspects, meaning it is chosen for many of Case's most popular blades.

Knife Handles

Knife handles are hand-crafted using natural materials such as animal bone, ivory, mother-of-pearl and precious stones. Brass, nickel and silver are utilized to make other knife components, such as bolsters.

Collectible Case Knives
Because of Case's long history and the company's habit of engraving a date on and, in some instances, numbering every knife, many of their blades are now classified as collectible items. Several hard to find knives cost hundreds of dollars online. The W.R. Case Collector's Club boats 18,000 collectors, making it the largest blade collector organization internationally.

Additional Reading
W.R. Case's online home is here. Another great source of information can be found on the Wikipedia.