All About Pocket Knives

As a general rule, when a knife has a main blade with a slight wobble, is there anything one can do, short of taking the knife apart to get rid of that wobble?

I've had a chance to buy several old knives but passed because each one had a slight wobble, and to me it's a deal breaker. I'd like to hear some thoughts on this. And as always, all comers are welcome...

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Mike

I have padded with leather belt strips (I use for stropping) and tapped the pin area with a rubber mallet.
One time it seemed to fix the problem.

Good question!!! Looking forward to others replies!

I have used Scott's method to take the wobble out of a couple of knives myself. I'm no expert but I do know you don't want to overdo it because you can end up with a blade that is so tight you can't easily open or close it. A real knife mechanic would use a shim to maintain proper spacing between blade and liner, but I'm certainly not a real knife mechanic.

I wrapped.mine in leather and used a rubber hammer or a vice. With the vice I sung it up test the blade ,still wobbling do another 1/2 turn and retest till I'm happy .

Pick up a few (cheap) and experiment. I've peened a few, over-peened a few. Experience is a great teacher

SteelMyHeart85420 wrote:Pick up a few (cheap) and experiment. I've peened a few, over-peened a few. Experience is a great teacher

Well said SMH!
There is no substitute for practice!

If it is a user knife and a mark on the bolster is not a huge deal; use a brass punch and lay the back side of the bolster on another piece of brass or aluminum and give the punch a light to medium smack with the hammer. Or you can use a center punch placed in the center of the pivot pin and give it a light tap. It is crude, but an effective "field expedient" fix for a wobbly blade.

Dale, you say to: "give the punch a light to medium smack with the hammer" but you don't say where to place the punch.
You describe a second method in which a center punch is placed on the pivot pin & tapped. Does one also place the punch on the pivot pin for the first method ?
And is "center punch" the same tool as a "prick punch" ?
kj

More questions !
The pivot pin being slightly loose is one cause of blade play. Are there others ?
What about wearing down of the tang and spring interface, will this give the same type of free play ?
if so then presumably peening of the pivot pin would not remove the play ?
kj

Oil the joint.

Slowly squeeze the bolsters in a vice between two pieces of soft wood, like poplar.

Squeeze and check, squeeze and check.

When you're satisfied and finished, the pin will be a bit "proud", so sand it down flush on both sides, then buff or otherwise polish the bolsters.

Good as new.

Charlie Noyes

Blade wobble is usually a problem that can be fixed but every knife is different and the cause of the wobble has to be determined before a proper fix can be used. The fix will vary and depend on the nature/cause of the wobble. Some fixes or repairs can be quite simple while others can be complex. What might fix one knife's blade wobble could actually create a worse problem for another knife.

I tried the vice trick. I squeezed it slightly, examined, squeezed, examined, etc several times.

I padded the vice well so no there would be no scratches. It helped a little. Further tightening

did not do any good. I think it was a Case 6244 bone, 1970.

Bob

The squeezing or tapping methods do not work for Schrade knives with a Swinden key construction. Maybe Eric or Dale might comment on 'how to tighten up a Swinden'.
kj

I would never recommend putting a knife in a vise and squeeze the bolsters to tighten it up!

As it has just been mentioned you will ruin a knife that uses the Swinden system. Also old German made knives had hollow bolsters and if you squeeze them in a vise it will dent or collapse them! Not to mention you can bend the pivot pin using a vise, Wayne gave very good advice already.

I would recommend visiting the knife mechanics forum here at AAPK and learn how to do the job right or send it to one of our mechanics to do it

Timely subject as I just finished tightening one up. My old Wards stockman that I love, I noticed had some wobble in the clip blade. I thought I'd checked it when I bought it, but I guessed hadn't.

I took it to the picnic table, put a .007 feeler gauge between the outer liner and the blade tang, and gave it a couple licks with the rubber mallet. I like to use a feeler gauge because I've been guilty of getting them too tight in the past.

Also, I start out with light taps and increase as needed.

I don't believe the rubber mallet is a long term solution, it'll just work it's way loose again, the pin needs to be peened---and filed and buffed/ polished, if you're all anal about it. Tis why i suggested inexpensive, non-Swinden-keyed knives to practice on. DO IT! (p.s., the feeler gauge/ slackener is a good idea, one of those "lessons learned")

SteelMyHeart85420 wrote:I don't believe the rubber mallet is a long term solution, it'll just work it's way loose again, the pin needs to be peened---and filed and buffed/ polished, if you're all anal about it. Tis why i suggested inexpensive, non-Swinden-keyed knives to practice on. DO IT! (p.s., the feeler gauge/ slackener is a good idea, one of those "lessons learned")

Yeah I learned about the feeler gauge the hard way. Lol.

The mallet may not be the best, but I don't remember having one come back loose. This one may, we'll see.

kootenay joe wrote:Dale, you say to: "give the punch a light to medium smack with the hammer" but you don't say where to place the punch.

On the pin.

kootenay joe wrote: You describe a second method in which a center punch is placed on the pivot pin & tapped. Does one also place the punch on the pivot pin for the first method ?

Yes

kootenay joe wrote: And is "center punch" the same tool as a "prick punch" ?
kj

If you Goggle them they are technically different tools, but either one will probably work in this case.
The intent is to spread the end of the pin so it won't pull out one side or the other.

pressure pliers and leather strip. it's easy to calibrate the pressure.

Dale, thank you for answering my questions. Finally now i understand how this should be done.
kj

I recently found a new Case small whittler - appaloosa mottled green, really nice dress pants knife. The main blade had too much wobble right out of the box (shame on you Case, but thats another story), and usually when this happens (as I have no tolerance for wobble on a new knife), I just resell it. I like this particular one too much to do that so I figured the boys at AAPK would lead me in the right direction.

Well, after futzing with it for a while using the leather and vice method (it's a fine line between getting it too tight where it won't snap closed at all & just loose enough so it snaps somewhat with no wobble) ... I'm ok with a little less snap & zero wobble. THis is pretty cool - I will be able to "fine tune" my knifes a little better now - thanks for your advice - appreciate it !!

As a big fan of the green Case Appaloosa and a collector whose #1 pet peeve is probably blade wobble, I think you made the right decision. That's a fine-looking knife.

I think I may need to further investigate the "leather and vice" method. It might be a little less heavy-handed than the mallet-and-towel or "peen and pray" methods I'm aware of to tighten up a loose pivot, and I've got a few nice knives in the collection that I'd really like to keep but don't get much use due to a little bit of blade play.

Use locking pliers

rarreola wrote:Use locking pliers

Good idea on the Vise-Grips. How big a turn do you use when you reset the pliers? I would think a full turn might be a little too much, no?

Tsar Bomba wrote:

rarreola wrote:Use locking pliers

Good idea on the Vise-Grips. How big a turn do you use when you reset the pliers? I would think a full turn might be a little too much, no?

Just 1/4 turn

1/4 Ton arbor press, using a shim next to the blade? ftd