Spyderco Forums

Hi, I’m looking for some advice from the Mule experts.
I bought a ZDP Mule second then decided to use the factory scales. The barrels in the scale kit will not pass completely through the scales. They only ‘fit’ from the presentation side and stop approx.1-1.5 mm before clearing the opposite side.
Given the concern around the brittleness of these particular mules and my
ham-handedness… should I
(1) try and bore the holes lightly or
(2) emery the barrels to get a better fit or is there an option (3)?
Thanks in advance.

Personally, I would find the location on the hole it is binding up and use sandpaper wrapped around a rod

I'd do the same. Not necessarily that it's the right way to do it, more that it would be easier to hold the blade blank and sand it than hold the barrel and sand it. I would invariably flat spot that barrel if I tried to sand it.

I would sand the barrels as they will be softer steel as they would not be hardened.


Cut a strip of sandpaper as thick as the barrel. Screw both screws into the barrel and place inside a vice or a locking wrench (like below)



It really shouldn’t take that long to sand them to fit through the mule holes. Try 120 grit wet and dry sandpaper

Always modify the least expensive part, if you have the option. That means adjust the barrels to hit the holes in this case.

Thanks to you all for your advice. It is very much appreciated.
I was able to look in the holes in daylight and could see a small burr in each one. Possibly from the final part of the laser cutting process…
I used a small diameter diamond file to ‘gently’ remove them. Checking the barrels fit as I went.
The knife is now scaled.

Ngati Pom wrote: ↑

Tue Jan 17, 2023 4:06 pm

Thanks to you all for your advice. It is very much appreciated.
I was able to look in the holes in daylight and could see a small burr in each one. Possibly from the final part of the laser cutting process…
I used a small diameter diamond file to ‘gently’ remove them. Checking the barrels fit as I went.
The knife is now scaled.

I had the same trouble getting the threaded insert in my mule. It would start on one side, but not the other, even if I flipped the mule over. I was considering doing without it, it was the middle hole and would have glued the screws in place for appearances. I got it sanded to the point where I could tap it into place. Looks good, and it’s NOT going anywhere! Now if I ever sell it, I can claim I hand finished it. Glad to hear you got your handles fitted too.

Brant wrote: ↑

Tue Jan 31, 2023 5:07 pm

Ngati Pom wrote: ↑

Tue Jan 17, 2023 4:06 pm

Thanks to you all for your advice. It is very much appreciated.
I was able to look in the holes in daylight and could see a small burr in each one. Possibly from the final part of the laser cutting process…
I used a small diameter diamond file to ‘gently’ remove them. Checking the barrels fit as I went.
The knife is now scaled.

I had the same trouble getting the threaded insert in my mule. It would start on one side, but not the other, even if I flipped the mule over. I was considering doing without it, it was the middle hole and would have glued the screws in place for appearances. I got it sanded to the point where I could tap it into place. Looks good, and it’s NOT going anywhere! Now if I ever sell it, I can claim I hand finished it. Glad to hear you got your handles fitted too.

Hand finished…
I might have to use that too.

Diamond file great for the burrs. To open a hole one might try diamond bits and a moto tool. Those diamonds do a wonder on glass. I loaned my set to a lady that does glass doo dads from bottles.