Lab Grown Sapphire - The Hardest Thing We’ve Ever Cut 

I'm sure everybody knows what you meant, but on a mechanical engineering/ materials science perspective, "toughness" is a very specific property. The sapphire is extremely hard, but there are plenty of tougher materials. Hardness relates to the force needed to deform it, while toughness is the amount of energy needed to deform/break it. Extremely hard materials tend to not be very tough materials. Sapphire is actually relatively tough for such a hard material, but just about any metal is tougher. It also doesn't help that the abrasive material they typically use, garnet, is dramatically softer than sapphire. Unless they swapped for silicon carbide, boron carbide, or diamond abrasive and didn't mention it, they're trying to do this cut with a tool that's not appropriate for it.

@@markjacobson4248he probably meant hard to do/a lot of effort by toughest, not the materials actual toughness.

@@markjacobson4248 or boron nitride

Sapphire is hard and brittle, not tough. The reason this took so long to cut is because sapphire Mohs hardness is 9 and the garnet mixed in the water that's used to cut it is Mohs 7. The reason they are getting through at all is speed. The original guys of this channel cut a fire hydrant three years ago that took 87 minutes. It took that long because there was a lot of material to cut, even though cast iron is mohs ~4

@@Kaelygon obviously the larger the object the longer the cutting time. but the sapphire was very small compared to that fire hydrant, and as you said it has a Mohs hardness value of 9, and can't actually be scratched by the garnet. the cutting action here is exclusively the sheer force and speed of the garnet chipping off little pieces of the sapphire. if sapphire wasn't "tough" (fracture resistant), as you're suggesting then the garnet impacts should have cut (chipped) it much faster. it would be like cutting quartz or glass.

Ur mom's eye clean.

This

Agreed. I design 6000m rated deep sea camera and laser scanning equipment that frequently use sapphire viewports. A viewport like that one would typically only run us 500-1000 usd depending on order quantity. Special coatings and purity constraints can ofcourse increase the price considerably.

Yup I used to work with optical grade sapphire, both for windows and lenses as well as lasing crystals, titanium doped. They are red like ruby but lase in the near infrared over a wide wavelength range.❤

"Gemmologist" Yeah ok, and Im a Space Pirate. See I can make up jobs to

Yeah!

Hey man, ive been enjoying the other stuff too though. Always love when these goobers upload

I feel that

@@landronsc I agree but, I joined this channel years ago when it was the old crew and they just cut stuff.

@@betafishjeremy7454 yeah i was there too, but i dont mind these 2 dinguses

Sears watch and jewelry repair sold them for as cheap as $40 and go up depending on size and complexity

Isn't aluminium oxide sapphire redundant? Probably a marketing call on this one.😂

Apparently they only started using sapphire crystals for watches in the 1960's. I have a watch case that, I believe, has a hand blown crystal. At least that's what it looks like, as the watch movement was an 1800's fusee.

Well, the original thumbnail shows the one in the video. Then they asked themselves "You know what this video needs?" - Clickbait. And there is the new thumbnail which is all nice and clickbaity.

I don’t think that’s from the jet, I would assume it’s the camera equipment just reflecting in it, ring lights.

@@Reactiontime6000 Its either caused by the abrasive making sparks or by the immense pressure and friction where the water+abrasive hits the material.

@@Sharpless2 dang

Sapphire may be triboluminescent?

@@Reactiontime6000 the waterjet can definitely make light. when cutting quartz it was dramatic enough for the guys to point out

They always find their way! :)

Yup those lenses are not cheap, and small ones are usually good for most uses. They are best for the mid wave IR as an alternative to germanium or znse lenses in tough environments. ❤

Yeah this jet uses garnet

@@DanTehBro they can cut with or without it. Some materials can be cut with just the water itself but yeah, this cut used garnet.

You wish it was

@@nanaki-seto He's almost certainly right. I have tons of watches that have sapphire crystals to protect the dials. You can google it, sapphire crystal, they're fairly cheap. *There is a treatment where they apply a sapphire coating to a less scratch resistant mineral crystal so that can also be the case with a phone or some very cheap watches. In fact the company he talked about in the video, Shellrus, makes a sapphire screen protector for $65.

@@nanaki-seto You probably own an iphone, loser.

​@@nanaki-setosome phones do actually have a sapphire screen

@@nanaki-seto many phones use sapphire in the screen. Its not any better than regular glass tho, breaks just as easily. It is massively more scratch resistant tho.

Yes. They all have crippling anxiety 😟

the nozzle does need to be replaced after some time but I don't know how long they last.

It depends on what you are cutting I run a water jet every day and the more penetrating you do the faster it wears out but if you cut thick metal with less pierces it lasts a lot longer but lots of piercing wrecks the nozzles fast

@tadenabbink3395 Oh, interesting. So it sounds like it mostly the splash back that deteriorates the nozzle... I thought it would be more like FDM 3D printing with an abrasive material (like carbon fiber filaments) through a standard brass nozzle, where the abrasive filament quickly wears away the inside of the nozzle, drastically widening the opening of the nozzle.

@@bluegizmo1983 it does wear down the inside on general use but the main wear down is the splash back that is correct

short answer yes, long answer, also yes.

where on earth did you get that idea

@tsm688 just sayin' a whole series would be kule. Obviously it was based on the video.

@@SonOfPerditionMedia That was sarcasm. That was this channel's entire reason to exist for years. People would send them things to cut in half every week. Now they do world's heaviest take four, world's hardest cut take four, world's fastest wheel take nine, what happens when you put in the waterjet take seven. They're no longer having fun and it's very sad to see.

@tsm688 I could tell it was sarcasm. Just seemed like a good idea, and I followed this channel all that long.

Garnet powder in the water

Not really true. How else would carbide inserts wear from mild steel?

Stronk water