Displaying Knives

[spike116]

Would displaying knives with the blades half open or somewhere in between be harmful to the backspring.
I am eventually going to make some display cases for my Case/Carhartt collection and would like to have the blades open.

 

[Markesharp]

Would displaying knives with the blades half open or somewhere in between be harmful to the backspring.
I am eventually going to make some display cases for my Case/Carhartt collection and would like to have the blades open.

You will be fine. Just oil the joints and open and close them every so often.

 

[mykel m]

I would go with fully open or at the half stop if there is one.

 

[spike116]

Thanks guys.

 

[slide13]

I wouldn't store them long term with the spring stressed....may not do anything but wouldn't sit well with me. Fully open or at a half-stop if it has one.

 

[waltmc]

Although things will probably be fine, I probably would recommend against it as a long term option. Here's why: A year or so ago, I bought a 1997 Buck 303 Cadet in a holiday gift tin. I bought it as a user (because of the flat ground blades), not as a collectible. The knife was displayed in the tin with all three blades partially open, and had remained unused and undisturbed for all that time; roughly 16 years. In the course of that time, the collective pressure of the springs on the pivot pin managed to crack the liners right at the pin. The knife still held together and functioned, though the snap of the knife was unsafely weak. Whether this was a function of the cracked liners or the springs having been weakened is unclear.

Either way, the knife was damaged from being displayed with all blades partially open for such a long time. This is--admittedly--an extreme case. The folks at Buck whom I spoke with said they had never seen such a thing, and I'm inclined to believe them. This might have been due to a specific defect in my knife, but it confirmed in my mind that leaving a slipjoint with the blades partly open was probably not a good practice in the long term.

 

[Brian.Evans]

Steel works like this. Geometry/thickness of the steel determines flex. Hardness determines whether a piece of steel takes a set or fails when it passes the modulus of elasticity.

Slipjoint springs are hardened around 45-48 rhc. This allows them to be springs, bend and return to their shape. However, if they exceed the point, they will take a set, or break. Theoretically, normal operation shouldn't do that, including leaving them at half open. However, I've seen enough knives ruined like that too believe that some knife patterns must push the springs right to the edge of too far bent, and leaving them stressed for a period of time causes them to bend slightly, causing weak springs. It only take a bend of a few thousands of an inch or less to make a floppy blade.