how to attach a diamond to a rod to make a wheel dresser?

I have got some industrial diamonds and would like to attach the biggest one to a rod to make a wheel dresser.
But how are they attached?

You can drill a shallow pocket in a piece of mild steel, then peen over the edges to capture it. More sophisticated methods may require treating the diamond to make it 'bondable". You can get information by searching for diamond bonded abrasives:

Diamond Tools: How to Choose the Bond – Diamond Blade Select

to make a diamond tipped dressing rod, first select the diamond

the diamonds are usually first sorted by approximate weight, most often fractions of a carat for a typical dressing tool, 1/4, 1/3, 1/2Ct, etc. (one carat=.2 gram), by passing them through a series of "sieves".

they are also selected for suitability for use in a dressing rod. this requires a "pointy bit", a place where the crystal faces converge at a suitable angle, not too acute or oblique (think something like a 60 deg. lathe center) probably something in the 60 to 100 deg range, enough to cut, but not so sharp it disintegrates instantly. it is also inspected for major flaws that would weaken it. it needs to have a suitable taper away from the point, so that the diamond is mechanically retained in the next step.

the steel rod is drilled with a hole or pocket just large enough to accept the selected diamond with the working point facing up, on axis, and the pocket is filled in with "silver solder" (braze) which surrounds the diamond, wetting the steel, but not the diamond. by surrounding the diamond, which is wider at the bottom, and filling and bonding to the steel, it is secured in the rod.

Thanks for the answers
It is the brazing i wonder about.
I did read that diamond starts turning into graphite in air at temperatures above 700 celsius.
I have some silversolder that will melt beneath that temperature but my torch is way higher in temperature.
Or is it just a matter of being quick about it?

yes, diamond will "burn" in air, but it is a very slow process below a bright orange heat (1000c). it results in a "frosting" of the surface only, for the most part. that wouldn't matter at all for a dressing point.

It WOULD matter for a diamond set in jewelry, and , yes I found out the hard way!(platinum repair, "white" heat, 1400C, I think? it was a long time ago)

also, the brazing flame or atmosphere(should be) a reducing one, so, the bottom line is you don't need to worry about it.

diamonds are pretty tough, but will crack from extreme temp changes,(especially if there are certain types of internal flaws), so DON'T quench!

In other words, actually, don't be too quick about it! a reasonably quick and steady ramp up, and a slowish cool down, "playing" the feather of the flame tip over the work to keep it in a protective atmosphere as it cools, you know, just like any other slow cool with a manual oxy-fuel torch. cheers, and happy brazing (and dressing)!

thanks a lot
i will give it a try

I frequently use high strength silver solder in my shop. But, I have to think this may be one of those time that a lower silver temperature solder should be adequate. Grobet Stay-Brite High Strength Silver Solder Kit
There is very little stress on a dressing diamond. Could it heat enough to come loose? Maybe.

I think that I would just call National Diamond Laboratory in LA. They reset diamond dressers all the time. They are also helpful. Betcha they would tell you how to do it. http://www.diamondtooling.com

Denis

janvanruth said:

Thanks for the answers
It is the brazing i wonder about.
I did read that diamond starts turning into graphite in air at temperatures above 700 celsius.
I have some silversolder that will melt beneath that temperature but my torch is way higher in temperature.
Or is it just a matter of being quick about it?

Click to expand...

Pardon my contrarianism, but for all the 'good stuff' on-offer in-thread so far, I've found it more productive to take advantage of simply ordering the wanted shank size and Ct weight from the rather large lot of ready-to-use mounted diamond dressers already in a crowded marketplace.

From a few at $6, through many at $20, and larger ones at only $40 or so, the very top brand names even at $80, and with no pressing need to impress anyone with a brand on one of Mother nature's diamonds? The wheel at its work careth little.

All these worthies are already mounted and ready for use, so I cannot be bothered to prep a rod, nor find which of the several solders stashed about might be the best one, and light a torch - not even if I were to find alluvial rough diamonds amongst the latest bag of Home Depot pea-gravel I've been using to pave a driveway extension.

They DO usually last through more than just the one pass at dressing a wheel, after all.

Isn't this really in about the same category as refilling disposable Bic lighters, just because we've figured out HOW to do?

???

Monarchist said:

Pardon my contrarianism, but for all the 'good stuff' on-offer in-thread so far, I've found it more productive to take advantage of simply ordering the wanted shank size and Ct weight from the rather large lot of ready-to-use mounted diamond dressers already in a crowded marketplace.

From a few at $6, through many at $20, and larger ones at only $40 or so, the very top brand names even at $80, and with no pressing need to impress anyone with a brand on one of Mother nature's diamonds? The wheel at its work careth little.

All these worthies are already mounted and ready for use, so I cannot be bothered to prep a rod, nor find which of the several solders stashed about might be the best one, and light a torch - not even if I were to find alluvial rough diamonds amongst the latest bag of Home Depot pea-gravel I've been using to pave a driveway extension.

They DO usually last through more than just the one pass at dressing a wheel, after all.

Isn't this really in about the same category as refilling disposable Bic lighters, just because we've figured out HOW to do?

???

Click to expand...

Meh. What else are you gonna do with a handful of rough industrial diamonds, besides disappoint a girlfriend?

I recall reading that the diamonds were set in a metal alloy referred to as Spelter, and that in some cases the diamonds would be sent to be reset if they had worn to not being very useful, but I am of the same mind, they come cheap enough these days that one need only worry about it if one were looking for some way to fill the time...

Cheers
Trev

OP question was "how" not "does it pay", just saying'! fact is, its pretty easy to do. I could have made 3 in the time it took to craft the reply(s). "worth it" depends on a lot of factors... but, no, not usually...

now searching through a bag of home depot pea gravel for diamonds, THERE'S a waste of time!