How to attach handle scales with screws?

Crayola

Crayola

Joined
Sep 23, 1999
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OK everyone, here's one that some very talented folks have tried to explain to me, but I still get lost! Never mind folders for now, that is too complicated. Suppose I wanted to make a knife with scales and attach the scales with screws. How would I do that? Are there special screws to use? If you drill a hile through the tang, do you thread it half way through one side, and then half way through the other, so that your screws line up on both sides? How exactly do you countersink?

Sorry for these simple questions! It has been a long time since I've used a tap & dye set, so I'm starting with the basics here guys :)
 
Karl,
One basic thing to remember is that you have to get at least 3 threads into the material.
6x32 is a good size for most fixed blades. That's 32 threads per inch, so in an 1/8" thick tang you'd get 4 threads. Not enough. In 3/16" stock you'd get 6 threads. That would work. 6x40 is better but harder to find that size screw.

Layout your holes, drill them to the correct size for the tap and then clamp one handle on and drill thru. Unclamp it and clamp both handle slabs together and drill thru the first one.

Redrill the handle holes to allow for pass thru of the screw. Use a larger drill bit to do the countersinking for the screw head. Best way I've found is to set your drill press depth and bottom the bit out, rather than try to stop at a certain depth.

Tap the holes in the knife tang and grind the screws to length. Screw them in from each side.

Another option is to drill the holes in the tang and just insert a piece of threaded rod, cut and ground to length.
 
There are also special screws that have a male stem and a female stem. You just drill the hole, countersink and screw in. These screws have the head that can be ground flush with the scales.
They are pretty big, though.
 
They are also called Chicago Screws. I buy mine at a leather place because theb have nice shiny brass ones.

For my knives that will be getting a lot of hard use I use a different method.

I drill the holes for the screws in the tang and then drill 2 more holes front and back for keeper pins. These just take some of the wear and tear off the screw holes. The keeper holes get reamed so the pins are a tight fit and the blind holes in the handle are reamed also. I grind a very slight taper on the keeper pins so they slide in the handle without a lot of trouble.

For the screw, I use a 10-24 bugle head allen screw and turn a nut completely round. I use my dremel and a needle file to cut a slot across the rounded nut and epoxy it in the handle with the slot showing. I put the handles on and trim the screw end flush. I cut a slot across the screw end also and align it with the slot in the nut. This is just window dressing. That handle does not move. It's also not as attractive as the chicago screws!
 
Crayola,

The pivot barrels and screws that are used in folders work great. Drill a couple of holes in the tang just big enough to fit the barrels. Counter sink the inside of your handle material a bit and grind the pivot barrel to fit. Countersink the head of the screws on the outside of the scales. The 1/8" barrels are nice for bolsters and the 3/16" ones work well for the scales.

Take Care
Dean
 
you could just drill the holes and use pins that will fit in the holes you drilled then peen them. i use 2 ton epoxy and glue the handle material on the tang first and then drill the holes tale my dremal and cut a few grooves in the pins lengthwise for some more epoxy and then drive them into the handle let dry about 24 hrs and peen and grind off flush it works for me WHY USE SCREWS FOR FIXED BLADES ? ONCE I DECIDED TO TAKE ONE OF THE ONES I MADE APART I HAD TO GRIND THE PINS AND HANDLE OFF SO I KNOW THIS WILL STAY TOGETHER!
 
Bart, the biggest reason for using screws on a fixed "HUNTER" is to be able to clean out the blood every once in a while. No matter how well I seal them, blood seems to get under the handles. It will rust carbon steel like nobody's business.
 
you can eliminate a lot of broken tap, not enough threads in the hole types of worries like this.....these are called "electrical standoff's".....the ones pictured are 1/4" round and 1/4" long, threaded for 4-40 screws...they come in all different sizes and thread gauges, these are stainless but can be purchased in all types of metal & even nylon.....

DCT has the right idea as to their use, this is just a cheaper alternative than buying pivot pins.....drill your tang to accept the standoff, they will protrude a certain amount depending on tang thickness & standoff selection..,counterbore the inside of your scales to accept the standoff height, continue with normal countersinking of the outside of scales to accept screws & you're home free.....and easy.....

I would post a link to where to buy them, but it's been so long ago I've forgotten......I did a google search for "electrical standoff's" when I purchased these.....
orig.jpg
 
Thank-you very much for your help on this!

I asked my question for a few reasons. The main reason I make knives is to learn about them, so in the future I'd like to make a knife with scales that are screwed on. Secondly, I made a chef's knife with pinned, stabilized, fancy wood scales. Though I told the customer not to leave the handle in water, or put it in the dish washer, the scales have separated from the tang. Lookign at the handle, I could tell immediately that the knife had been in water, and I think it took a ride in the dish washer (the nice buffed handle lost its shine and looked quite weathered). I'm just thinking that for some folks that I make kitchen blades for, screws may help prevent stuff liek that when peopel put fancy wood in a dish washer :)

I'll do some searching for those thread gizmos and maybe pick some up around christmas!
 
Frank,

Great tip...Thank you! I was hoping to find an alternate source for these :)

Take Care
Dean
 
Another reason to use screws is so you can bring the whole knife to a finished state, then take it apart and treat the blade - etch damascus, epoxy coat, whatever. Then reassemble. Won't happen using pins, regardless how well they fit.

Dave
 
Standoffs for electronic equipment can be purchased through electronics distributors such as Digikey (www.digikey.com, 1 800 344 4539) that will serve the retail market. Look on page 1009 of their catalog or go to their website, click on "catalog", "hardware --- jumpers" then "spacers/standoffs 1008 - 1011". Do not use the nylon ones, they are quite soft and will strip out. The aluminum ones are also fairly soft and may strip out. the zinc-plated brass ones are OK. Digikey does not sell ones made from steel, but they are the strongest and are more likely to be available only in large quantities (say 10000 pieces) on a special order. Digikey sells the round, zinc-plated brass ones in packs of 10 ($2.62 - $3.74) or 100 ($22.56 - $32.13) for the 1/4 inch to 1/2 inch long ones. Buy the larger quantities once you are sure which one you want since the shipping/handling ($5 for Digikey) may be more than your parts.

The shortest that Digikey sells is 1/4 inch long and would allow only 4 threads for each 6-32 screw, if the two screws touched in the middle and the spacer was centered on the two screws. Probably better to use either 4-40 screw or a longer spacer. If your handle is so thin that you cannot accomodate longer spacers, or even a 1/4 inch long one, then you probably have such a small knife that it would be hard to put enough stress on it to strip out the few threads that you have engaged. Drill the hole in your tang, and any recesses in your scales, a bit bigger (say 1/32 inch) than the diameter of the standoff. I have seen some, at work, where the hole was not exactly in the center. Make sure that you trial fit ALL of the pieces before you put the epoxy on.

Check that the screws that you use are good quality ones. I have bought some that were really soft steel. The threads would strip out, the heads would deform or the plating flakes off quite easily. I do not recommend getting screws from electronic parts distributors, like Digikey or Radio Shack, for this reason. Go to a proper fastener distributor. I have never had a problem with stripping or deforming stainless screws or screws with allen key heads. Some of the allen head screws that I have used have rusted quite easlily though. They are the black ones sold in hobby shops to hold engines on model airplanes.

Phil
 
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