I am thinking about buying an old USA Craftsman 1/2 inch torque wrench. But I am not sure whether this type of 'crude' torque wrench can remain accurate after a long time. Anyone has any suggestions? Does it look like a collectible item? Thanks!
I think your question about accuracy has been adequately answered. Let me address collectability.
It depends.
As the character Belloq in the Raiders of the Lost Arc noted; bury a worthless pocket watch in the sand for 1000 years and it becomes priceless.
Several members have noted they own beam torque wrenches that are 40-60 years old--I myself have a Super Indestro 8099-1/2 in the style that was made from the late 30s to the early 60's (probably looks just like
Lardy's Duro). Are they collectable? Meh.
If they are in great shape; if they still have the box they came in; if they are rare, if they belonged to a famous race car team from the 50's... These things might make a "Tension Indicating Wrench" worth more money than one that doesn't have those qualities and therefore may be worth collecting.
On the other hand--and more importantly--is the item or category of items something that grabs your interest? Is it something that you enjoy reading about, researching, and spending time discussing? These are also factors in collecting. If you have no real interest in an item, how will you know if or when you run across an example that is collectable--or at least one that is priced well below market value?
So, is the Craftsman torque wrench you are considering collectable? Maybe to some but not by me, but I'm not that into torque wrenches.