1920-40 marks a period of very high quality pocket knives and ingenuity for the Case brand.  Many of the patterns that would thrive into the next 50 years would come from this most important era in the company’s history.  The “Tested XX” trademark was officially registered in 1905 by Jean Case of the Case Brothers Cutlery Co of Springille, N.Y.  In 1914, Jean sold the rights of the Tested XX trademark to J. Russell Case of W.R. Case & Sons Cutlery Co for the sum of $1500.

Case Tested XX Pocket Knives
1920-40 Case Tested XX pocket knives

The stamp from the 1920-40 era features a large circle C that extends underneath the “ASE” in Case.  Underneath this were the words, “Tested XX.”  The shields on the handles from the Tested era feature a “closed” C in the word Case.  After 1940, most of the shields had an “open” C.

The bone and stag handles from this era are remarkably striking as well.  These Case Tested XX pocket knives are scarce and highly sought after by collectors today including the large cigar, large stockman and large congress knife.  Check out my Case knives page and Remington knives page as well.

I appreciate any traffic from these links as I earn commission when an item is purchased, at no extra cost to you. THANK YOU!!!   – Jesse, oldpocketknives.com

Case Tested 1920s knife (28658)
eBay
$1,700.00
Case Tested 1920s knife (28658)
Vintage Case XX Tested 1920-1940 6165 Hunter Knife 1920-30s Bomb Shield Logo
eBay
$107.51
Vintage Case XX Tested 1920-1940 6165 Hunter Knife 1920-30s Bomb Shield Logo
Vintage Case Tested XX Jack Folding Pocket Knife Made In USA 1920-40
eBay
$149.99
Vintage Case Tested XX Jack Folding Pocket Knife Made In USA 1920-40
Case 1920-40 Tested Stockman Knife Made In The USA Pocket Knife
eBay
$225.00
Case 1920-40 Tested Stockman Knife Made In The USA Pocket Knife
CASE TESTED XX RARE GREEN BONE FLAT BLADE 6165, 1920-40 folding hunter knife
eBay
$465.00
CASE TESTED XX RARE GREEN BONE FLAT BLADE 6165, 1920-40 folding hunter knife
Antique Case Tested XX rough black cigar knife 1920 - 1940 two blade muskrat
eBay
$99.99
Antique Case Tested XX rough black cigar knife 1920 - 1940 two blade muskrat
1920-40 CASE TESTED XX 2 BLADE SLICK BLACK PEANUT KNIFE
eBay
$62.00
1920-40 CASE TESTED XX 2 BLADE SLICK BLACK PEANUT KNIFE
Rare Case XX Tested 1920-1940 Bomb Shield Stag 5265 Large Folding Hunter Knife
eBay
$975.00
Rare Case XX Tested 1920-1940 Bomb Shield Stag 5265 Large Folding Hunter Knife
Rare CASE TESTED XX 1920-1940 Military Style Harness Jack Knife Jigged Bone Bail
eBay
$449.99
Rare CASE TESTED XX 1920-1940 Military Style Harness Jack Knife Jigged Bone Bail
Vintage Case Tested XX Pen Knife 1920 - 1940 Yellow
eBay
$60.00
Vintage Case Tested XX Pen Knife 1920 - 1940 Yellow