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If you mean that the blade has some looseness in the direction of the arrows with the blade open, probably wear in the joint and is not readily fixable without a major effort.bhuber wrote:Does anyone have any tips/tricks to reduce some slight up and down blade play on a 1970 Case 6344?
Could be a worn pivot pin or a worn pivot pin hole in the blade. I’m not sure how common that is or why it would occur.tallguy606 wrote:I was wondering the same thing about a Schrade USA LB 7 folder that I have. With a thick steel blade, massive brass bolsters, and a heavy steel pivot pin in those bolsters, how could slight vertical play have developed? Which of these parts deformed a little? Assuming there was no play when the knife was new.
Yep, that is what I’m experiencing. Thanks for taking time to answer. It’s only slight and still a good knife for light cutting chores.OLDE CUTLER wrote:If you mean that the blade has some looseness in the direction of the arrows with the blade open, probably wear in the joint and is not readily fixable without a major effort.bhuber wrote:Does anyone have any tips/tricks to reduce some slight up and down blade play on a 1970 Case 6344?
IMG_2983.JPG
Awesome illustration and explanation Eric. Thanks!!!ea42 wrote:Up and down play on a pocket knife is caused by wear on the back tang, or a combination of the back tang and spring. Normally there is a gap beneath the spring when the blade is fully opened. This keeps downward spring tension on the tang, forcing the blade back tightly against the end of the spring. If that gap is closed due to wear, the spring winds up resting on the flat, cancelling out the forward pressure against the tang. If the wear continues to the point in third illustration, you've got a wobbly blade:
Knife tang wear.jpg
This can also happen if the spring is too short, but in that case the blade will appear to be over-extended when open, kind of sticking up beyond where it seems it should have stopped. this is referred to as a broken back.
A loose lockback blade is usually the result of the lock lever not engaging tightly due to a poor fit.
Eric
Big heavy knives are subject to abuses because people assume because a knife is heavy and well built it is indestructible, pins will bend/wear under excessive forces. I see it all the time with LB&, buck 110 and similar lockbacks. It is also possible that the steel in the mating surfaces has been worn or displaced from these forces/lack of lubrication over the years as welltallguy606 wrote:I was wondering the same thing about a Schrade USA LB 7 folder that I have. With a thick steel blade, massive brass bolsters, and a heavy steel pivot pin in those bolsters, how could slight vertical play have developed? Which of these parts deformed a little? Assuming there was no play when the knife was new.
