How scales affect folding knife operation

Discussion in 'General Knife Discussion' started by vanadium, Apr 19, 2019.

  1. vanadium


    Apr 5, 2003
    I've bought a lot of custom scales over the years, and found from the beginning that they would affect the operation of the knife, almost always for the better. It took me a while to get a clue as to why, but I think it boils down to screw hole placement and counterbore flatness.
    • If the screws heads fit snugly in the counterbores of the scale, but the hole placement isn't precise, then tightening the screws will cause torsion to the frame.
    • If the counterbore isn't flat (i.e., not sufficiently perpendicular to the standoff or pivot that the screw is going into) then the screw head isn't bearing equal pressure all the way around, which causes a lateral force that shouldn't be there.
    Nothing is perfect, so one or both of these problems are always present to some degree, and I think this is why a great set of scales tends to make the action better.

    Recently for the first time I got a set of scales that makes a knife work incorrectly, every single time. I've done four re-assemblies on 2 different copies of the knife, and they cause the detent ball to totally miss the detent hole, and also too-early lockup that lets the lock be defeated with blade pressure. Fortunately both knives went back to normal after putting the original scales back on.

    Has anyone else had good/bad experiences with scales affecting their folder?
  2. Whitedog


    Dec 30, 2005
    Good experience so far but if the screw holes are just a hair off your going to have problems. Frankly you are better off just sticking with original eqpt. After market does not make it cut any better. Last pair of after market scales I bought needed a slight adjustment with a file to the back side of the scales.
  3. DocJD


    Jan 29, 2016
    My policy is to only "open up" a folder that is otherwise trash .

    Tiny irreplaceable parts rolling around the basement floor and down the drains and under stuff , never to be seen again ! :eek:
  4. Boxer .45

    Boxer .45 Gold Member Gold Member

    Jan 11, 2015
    Ive put allen putman scales on a Delica that made it more "rigid" as far as scale flex. It felt more solid. The scales were well CNC'd and everything fit well. I like the action on a Delica in general, so I can't say it was "better", but I liked it.
    vanadium likes this.

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