# Best way to drill hole in Tungsten Carbide???



## Jumpmaster (Oct 4, 2003)

I'm thinking of buying some tungsten carbide balls from Mcmaster-Carr to use on my lanyards, but...what would be the best way to drill holes in them? Umm...I'm sure I'll use a drill press but what sort of bit...what will cut it? Aren't the really strong drill bits made out of tungsten carbide?

Sorry for the potentially stupid question, but it dawned on me after I found these that they may be a little difficult to drill. I like tungsten carbide because it's pretty dense and provides good weight for size...I think it would work well on lanyards...

Any help appreciated as usual... /ubbthreads/images/graemlins/smile.gif

JM-99


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## whiskypapa3 (Oct 4, 2003)

With a diamond drill and LOTS of cutting fluid. Most Tungsten Carbide is now cut with a CO2 laser...


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## Tomas (Oct 4, 2003)

Drilling holes in TC will be a time consuming and expensive proposition. The way to do it is as WP3 says, and you can expect any errors to eat diamond bits even faster - like 'instantly' ...


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## Silviron (Oct 4, 2003)

THREE LETTERS:

EDM

If you have a friend with access to an Electric Discharge Machining machine, you got it made... Otherwise...

The only way to do it "at home" is with diamond or cubic boron nitride bits, but be prepared for a long, frustrating time.

I wouldn't even bother to try.


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## Jumpmaster (Oct 4, 2003)

Oof...ok, I reckon that answers that question... /ubbthreads/images/graemlins/frown.gif I still have friends attending the local University, but I'm not sure what sort of equipment they have access to...

Would stainless steel be easier to do? Or maybe brass? Does anyone know offhand where to even find these in solid brass? I don't mind polishing brass...I've had to do it so often in the past, it's almost relaxing and therapeutic now...almost. /ubbthreads/images/graemlins/smile.gif

Thanks for the help, folks...

JM-99


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## McGizmo (Oct 4, 2003)

JumpMaster,

You might be able to find beads in some of the metals you have mentioned. Anything that already has a hole will be much easier to drill out for your lanyard materials. With all of the body piercing going on now, no telling what you can find!

- Don


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## Tomas (Oct 4, 2003)

No, no, Don, the holes are in the _bodies_ rather than in the hardware ... /ubbthreads/images/graemlins/grin.gif 

(Just realized my oldest piercing may be older than the median age of active posters on this board.) /ubbthreads/images/graemlins/ooo.gif


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## CNC Dan (Oct 4, 2003)

You can do it. It will take time.

Get some brass tubing at your local hardware store, and a brass rod that will fit inside the tubing.

Get some diamond paste. (industreal supplyers? MSC )Chuck the tubing in your drill press, using the brass rod to keep the tube from colapsing. Make a dam around the spot you want to drill, with clay or putty. Apply the diamond paste to the end of the brass tube and then start 'drilling'. The diamonds in the paste will embed in the brass and wear on the carbide. You will need to re-apply the diamond paste several times. Use some oil to keep stuff from packing up.


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## mylan (Oct 4, 2003)

Drilling in stainless steel is easy. You can use normal drill bits. Just use some cutting oil or paste and drill at relatively low speed, otherwise your drill will burn. if you sharpen your drill after burning it, it will not take an edge again.

Mylan


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## Jumpmaster (Oct 4, 2003)

*Re: Best way to drill hole in other balls?*

Ok, potentially stupid questions #2 and #3...(In case you can't tell, I've never done anything like this before...I've rebuilt engines and stuff, but nothing of this nature in particular...)

#2: mcmaster-carr has both steel and brass balls...(hmm...that sounds a bit kinky, doesn't it...) They have several varieties of steel, including:
Carbon Steel Balls
Chrome Steel Balls
Stainless Steel Balls
Stainless Steel Bearing Balls
Steel Bearing Balls
Tool Steel Balls
Tool Steel Bearing Balls

I was thinking of going with the stainless steel balls of type 302 SS. Any other ideas are wholeheartedly welcome...I would like good corrosion resistance and average hardness to resist wear. I'm going to buy some precision steel shim stock to make the sliders from.

#3: Once I get these, how shall I locate the central axis of the ball through which to drill? These do not already have holes started in them. What should I use to hold the ball in place whilst I use the drill press with it?

If you haven't checked out mcmaster-carr, you might want to...especially for the fabricators out there...I have no connection with them -- in fact, I've never ordered from them before, but they come highly recommended to me by a friend and they have a huge selection of stuff like this...all sorts of stuff, really...

Thanks for the good advice and info!!! You folks are very knowledgeable, as always!

JM-99


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## whiskypapa3 (Oct 4, 2003)

*Re: Best way to drill hole in other balls?*

Usual fixture for drilling balls is to use two metal plates of a softer material (Aluminum or cold rolled steel should work for stainless). Tape them to gether and drill a central hole of the desired diameter and three holes at 120 degrees for bolts. Countersink the center holes on the sides that were in contact. Drop ball in countrsink and put the countersink of the other plate on top and tighten down bolts evenly to grip ball. Useing a drill press helps but if the plates are thick enough you can get by with a hand held hole-shooter.

Back in my misspent youth I drilled a couple thousand bronze balls on a lathe with a collet ground to fit the balls. If you only need a few the two plate method is ok.

Holding them in a three jaw chuck doesn't quite work, to hold them tight enough to keep them from spinnig dents the ball, not tight enough leaves skid marks.

Anything harder than mild steel needs a Colbalt drill and a drill press...


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## Jumpmaster (Oct 4, 2003)

*Re: Best way to drill hole in other balls?*

Ok, so I'll try and make this jig...on the central hole where the ball will sit, do you just make it slightly smaller than the diameter of the ball so the two plates will clamp down on it tightly? Do you need a spherical-shaped countersink for that or can it just be a hole? How far down into the recess should the ball sit when bolted together? When drilling, do you just clamp the jig onto the drill press plate with c-clamps?

I think I'm going to have to use 7/16" or 1/2" balls...I'm going to try to order some 3/8" also and make a few ranger pacecounters and see how that goes...

Thanks for being patient with me and helping me out here...

JM-99


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## whiskypapa3 (Oct 5, 2003)

*Re: Best way to drill hole in other balls?*

The central hole is the size of the hole you want to drill in the ball and acts as the starting guide. The counter sink should be about 1/16in wide (eyeball precision)to grip the ball slightly away from the edge of the hole. If all goes well the drill should exit through the other hole.

The plates should be 1/8in or more if possible.

McMaster-Carr sells brass balls too.


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## Atomic6 (Oct 5, 2003)

*Re: Best way to drill hole in other balls?*

Whoa-You are sure making this into a giant task. Not a bad thing in itself. And like McGizmo says-there are metallic beads out there for starters. However, if you like the idea of using industrial strength fashion accessories for the new lanyards, then there is another component to study first: a hardenend ball bearing with a hole in it! These are used in ball-end control rod assemblies. I have seen them used on aircraft control surface pushrods. These are some sort of SS ball, or hardened steel ball which is captured in a rod end fitting:







These "ball ends" are 4130 Chromemoly Alloy Steel - Heat Treated. These are used on race cars too. Automotive and Aircraft supply houses have these.

Secondly, we have "Ball Valves", which are essentially a bearing with a hole which is captured in a valve body. These are plumbing devices, so your home depot should have the valves. You may be able to find "just the Balls" for these ball valves. These come in many material types.

It just doesn't make sense to set up to learn & machine bearings if all you want to do is make a few lanyards. But then again..... and are you sure you want to add an ounce to the light hanging off your neck?

Leastly-good luck. Lanyards are fun to design and build /ubbthreads/images/graemlins/grin.gif


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## Tomas (Oct 5, 2003)

*Re: Best way to drill hole in other balls?*

Hmmmmm ... where'd my post go? Nevermind, but that was weird! 






Anyway, R/C models use ball links, real aircraft use ball links, some racing carbrueters use ball links. Control links, ball ends, link ends, link balls, etc might be some of the searches that will turn up bags of 'em in everything from nylon throught brass, to stainless steel. Uh, helicopters us a a LOT of high-strength ball links - even models. /ubbthreads/images/graemlins/smile.gif 

Here's a link to an R/C site with some brass balls (I had to say it) in some links: Dubro 

I'm sure there are some places that have the replacement balls in different sizes and materials (the image at the top is from a Korean model site that has plastic bags of link balls for sale - if one could read Korean ...).

Doing an exhaustive search with Google for link balls would be easier than drilling even one tungsten-carbide ball ... /ubbthreads/images/graemlins/grin.gif 










(That one's the wrong size
2 1/2 inch gold irridited, 
hardened steel)


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## Jumpmaster (Oct 6, 2003)

*Re: Best way to drill hole in other balls?*

[ QUOTE ]
*Tomas said:*
(That one's the wrong size
2 1/2 inch gold irridited, 
hardened steel) 

[/ QUOTE ]

Umm...yeah... /ubbthreads/images/graemlins/smile.gif

I saw on McMaster-Carr they had some in bronze there, but they didn't have them small enough...smallest was 1".

Thanks for the ideas on the control rod ball ends...I will check into that, for sure. I've already sort of resigned myself to drill my own beads so that I can make sure I get a bead that "slides" on the lanyard properly...that and yes, I do like industrial grade hardware -- even to the point that at least 90% of my amateur radio communications equipment is military equipment. I like tough, durable things. /ubbthreads/images/graemlins/grin.gif

I was going to order some shims for sliders too, but...as far as the weight goes, it's negligible for me. I'd rather have something with some heft to it than something really light, but that's just personal preference. If I were going to hike the Appalachian Trail, I'd probably choose materials differently. These are going to be really industrial-strength lanyards, mainly as a pocket lanyard. You're right...I may think twice about carrying the extra ounces around my neck...I'll have to try it and see...

How about this for a slider? I have to check to see if they have an ID usable for any of the paracord I have...

http://www.mcmaster.com/param/asp/psearch.asp?FAM=DrillBushings&FT_158=30257&FT_724=31167&session=desc=Steel%20Shims;DrillBushings;158=30257;724=31167

Thanks for the clarification on the jig to drill these...it makes perfect sense now! BTW, my local Lowe's and Home Depot don't carry any aluminum plate...I'm heading to a place out in the industrial park here that has some and will cut it for me.

Again, thanks for the ideas on the beads...I like to try and tackle challenges like this if for no other reason than to learn how to do it. I could have taken my '52 Jeep engine to a mechanic to have them rebuild it, but I could never have learned the things I did by doing it myself. /ubbthreads/images/graemlins/smile.gif

You guys are great! Thanks for all the great info!!!

JM-99


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## Atomic6 (Oct 6, 2003)

*Re: Best way to drill hole in other balls?*

Hey Hey-That drill bushing should make a great Bolo slider. Lots of sizes to choose from and the quality is sure there. Keep us posted on your progress. I may have to get a few of those drilled beads from you. /ubbthreads/images/graemlins/grin.gif


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## Jumpmaster (Oct 14, 2003)

*Re: Best way to drill hole in other balls?*

Ok, some tips on ordering frolm McMaster-Carr...first, put in the comments that you want everything shipped from Atlanta...if not, they are going to charge you $8.25 shipping for a drill bushing that weighs less than an ounce. /ubbthreads/images/graemlins/smile.gif (They're refunding about half that after I pointed out that I chose "best way" for shipping and that they didn't use the "best way" to ship it! /ubbthreads/images/graemlins/smile.gif So good on them...they're still alright be me...)







Here is a pic of the lanyard so far...I was able to drill one brass bearing, though it didn't turn out like I wanted. I had some aluminum plates cut out at a local fab place to make some jigs to drill the others so they will look a lot better.

http://www.m998.com/lanyard1.jpg
http://www.m998.com/lanyard2.jpg

The drill bushing I used was a #10...it will fit that doubled-over camo paracord nicely if it's the same size as yours, Atomic6...The drill bushing and brass bead slide well on the cord and stay put really well. I put a 3/16" hole in the brass bearing...bearing is 7/16" dia. I have some 1/2" steel bearings I'm going to drill 5/32" holes in for some larger paracord I have.

Anyway, I'll add a picture of the plain brass bearing here later...I've been carrying it in my pocket to see how quickly it tarnishes...it has a nice patina on it now. (Needs polishing... /ubbthreads/images/graemlins/smile.gif )

JM-99


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