All About Pocket Knives

A while back I took a knife apart and made a backspring for it. As things go I missed on the location of the hole for the rocker pin by just a hair and the knife didn't line back up right and so it was back to the drawing board to make another spring. At that time I wondered what would be wrong with having a slot instead of a hole, with the diameter being the critical part of the opening. I reasoned that an elongated area would weaken the backspring and it would break apart like a Dollar Store lawn chair so I dismissed the idea. Today I took this Case folding hunter apart and low and behold there is a slot both for the rear and rocker pins in both springs instead of a hole. First time I have seen this and thought I would post it. What do you suppose? This same spring is used on other patterns and there is enough room to allow alignment? Any other obvious reasons for a slot instead of a hole?

Not sure why it was done, but I've seen it on one other knife--one of the ones I knocked apart to test hardness, etc on. That was also a Case folding hunter.

If you look at the springs, the shape of the arm is such that almost all of the flex/movement will be in the area where the width of the spring narrows down. Done like that, there is no reason it would be more likely to break. On the other hand, slotting a spring designed for a single hole would probably weaken the spring, by concentrating the flex around the new "slot".

Most of the flex on that spring should be from the hole forward, I would think.
If you widened the hole to the rear I doubt it would effect it.

Just my $. 02 worth.

I have see nthis before but can't recall where but this is the first I have heard of it on a case

I have also seen the slotted holes on springs, but never on both holes like that.

I can't see why they would do that, but maybe it was to allow some difference in liner/bolster holes so things would line up easier? They wouldn't want any excess movement of that spring in a finished knife, so I can only assume it was something put into place to aid the assembly of the knife.

glennbad wrote:I have also seen the slotted holes on springs, but never on both holes like that.

I can't see why they would do that, but maybe it was to allow some difference in liner/bolster holes so things would line up easier? They wouldn't want any excess movement of that spring in a finished knife, so I can only assume it was something put into place to aid the assembly of the knife.

It was either that or those springs were made during a transition period so they would fit both the old and new model frames of that knife. Sound reasonable?

Elvis wrote:

glennbad wrote:I have also seen the slotted holes on springs, but never on both holes like that.

I can't see why they would do that, but maybe it was to allow some difference in liner/bolster holes so things would line up easier? They wouldn't want any excess movement of that spring in a finished knife, so I can only assume it was something put into place to aid the assembly of the knife.

It was either that or those springs were made during a transition period so they would fit both the old and new model frames of that knife. Sound reasonable?

I agree, and find that a lot of knife design specifics are done with cost savings and flexibility in mind. It's just good business.