All About Pocket Knives

I have been curious about what the knife repairmen among you have been using for the thickness of the slackers installed when reassembling knives. I personally use a .007" slacker that I made from an automotive feeler gauge set. I was talking to a fellow at a gunshow over the winter who does some knife repair and I asked him what he uses for slacker thickness. He seemed hesitant to answer at first, like it was a trade secret. Then he told me "Well that depends". I asked "depends on what?". He stated that for knives for himself, he always uses a .008" slacker, but on knives that he is working on for other people, he uses a .012" slacker. He explained that people expect or even demand that knives that he works on for them have excellent "snap", so he builds in a little extra clearance so the there is no friction to interfere with the snap of the blade. I guess this would be considered a trade secret. Also do any among you use more than one slacker, that is if you use .007" total, do you use a .004" on one side and a .003" on the other side of the blade? Would there be any advantage to doing that?

I think I use somewhere around .010, but it varies. Use too thin a slackener, and you have trouble pulling it out of the joint after

Dale suggests 0.008" feeler gauge for a slackner. ---► viewtopic.php?t=13147
But based on my very limited experience I, like Glenn, prefer 0.010" and if I were to do another one would probably try out the 0.012", as suggested by the fella you talked to at the show.

In the knife repair book by Adrian Harris he suggests using a slacking tool that is .010 - .015. In the Ben Kelley book he has a diagram of making a slacking tool that is .015 thick. To each their own. I spoke with a guy that told me he pinned his knives with a .005 slacking tool. My own opinion is that feeler gauges makes great slacking tools. Buy a set and make one from the .012 gauge - when it breaks - and it will, use another gauge and make another one. Don't go buy a new set just to get an .012. You can try all of the gauges between .005 and .015 and see what works best for you. I've never had a problem with the .012 and have never tried .005 and probably never will. I haven't broken that many yet.

I’ve been using .007” feeler gauge and haven’t had any issues.

You can buy single feeler gauges that are about 12" long. Chop off a piece and when that one bites the dust, chop off a new piece.

I can depend a bit on how heavy handed you are with a hammer too. single blade knives I usually run something in the .007" to .008" range. If there are multiple blades on one end of the knife I use .012"-.015". Usually a single slackener as close to center as I can get it or two half thickness slackeners, one for each blade. YMMV

I make my slackners out of feeler gauges; use an abrasive wheel on a Dremel to cut the notch to fit over the pivot pin. I made the above slackners in 2008, and have added to them until this is what they look like today (below). Notice some of them have been broken off and reground, that happens.
I find flea markets and yard sales are a great place to find a set of feeler gauges. An old set of feeler gauges doesn’t have to be fancy, just in good enough shape that you can read the thickness and if they’re not rusty they should be good.

For $1, sometimes less you can get a whole set of slackners that will last you for years.

I find it works better for me to take them out of the case they come in and just clip them together with a split ring.
90% of the knives that I use a slacker on are .008". If it is a large knife, I will go up in size, the largest one my ring is .016", and I use smaller slackners on small knives. The smallest one I have on this ring is .006".

I can't wrap my head around that many different sizes. Being inexperienced, I would have thought the goal for the blade would be what we called, "snug but free". In other words tight enough that there's no wobble yet loose enough that the blade can move freely. To achieve that, my imagination won't allow the spacing to be different for different size knives/blades. An education on the practicalities would be appreciated.

I took some brass liners out of an old TL-29 I had and tapered the end down to the desired thickness, works like a charm and their practically free!

jerryd6818 wrote:I can't wrap my head around that many different sizes. Being inexperienced, I would have thought the goal for the blade would be what we called, "snug but free". In other words tight enough that there's no wobble yet loose enough that the blade can move freely. To achieve that, my imagination won't allow the spacing to be different for different size knives/blades. An education on the practicalities would be appreciated.

Each knife can be different based on liner material, spring strength, tolerance between blade thickness and spring thickness, whether it is a lockback, has a pivot bushing like an lb7 or buck 110. Few things are cut and dried in this business.

muskrat man wrote: Few things are cut and dried in this business.

Ain't that the truth!