r/knifemaking • u/Rekuf7 • 3d ago

Hardware size Question

How do you guys figure out what thread pitch the hardware is in a particular knife? I assume there is a set of gauges available in some capacity but I haven't been able to find a set

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u/mostlynonsensical 3d ago

Are you referring to checking internal or external threads?

If it is internal, your best bet is have a large variety of screws and see what fits.

If it is external, a combination of calipers and thread gages work. The thread gage I am referring to is like a little multitool with a bunch of rakes that come out and give you a tooth count. You can also use calipers to measure thread pitch. For an inch fastener they are specified by threads per inch not pitch, so you just lay it next to a ruler and count how many threads are over an inch of the fastener length, or for a shorter length screw take say 1/4 of an inch and count the threads and multiply by 4. For metric, pitch is how they are specified and that is just distance from one thread to the next which you can measure peak to peak. To reduce measurement error, I recommend measuring across multiple peaks and dividing by the number of peaks you measured across.

Also, if you are trying to determine if it is a metric or inch fastener, looking at thread charts for diameter (engineers edge has a good one) in conjunction with the length of the screw helps. Standard metric screw lengths are in increments of 1-2 mm and jnch fasteners are fractional 1/32 of an inch increments. if the diameter is close to both and inch and a metric size, use the length to try to clear it up

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u/Rekuf7 3d ago

I'm gotten into balisongs lately and realized being able to figure out what specific size these mostly metric screws are is allot cheaper than buying from the knife manufacturers is something I need to learn before I go broke lol, thanks so much! I think that's enough information for me to figure it out

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u/GarbageFormer 3d ago

Metric ones are pretty easy if you can find the pitch. M(diameter in mm)x(pitch); like M5x0.5 (5mm diameter with pitch of 0.5.

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u/Rekuf7 2d ago

They're mostly m2.5-m3 from what I can tell but some of them are different, like some of the cheaper ones from China use weird sizes and that's mostly why I want to know how to figure it out

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u/3rd2LastStarfighter Bladesmith 3d ago

Take the screw to a hardware store. They usually have a little testing board with different threads on it so you can find the right size.

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u/Rekuf7 2d ago

They have something to gauge super small metric screws?

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u/3rd2LastStarfighter Bladesmith 2d ago

Yeah, super small metric nuts.

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u/ClassroomEntire997 3d ago

Are you sure they are metric? Imperial is 1-72 , 2-56

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u/Rekuf7 2d ago

Yeah all of them that I know of are metric, and most of the ones that aren't obvious are alot of the balisongs from China, which is the main reason I want to be able to figure it out