Thread: nasty stuff that you have machined

I had to machine some mystery metal this week .

I later found out it is made to this standard ASTM A311-B ...damn thing was crome plated and induction hardened to Rockwell 50 to 55 on the "C" scale.

How often do any of you have the "odd" stuff that you end up doing.

Halar. Plastic thats will mold it self around end mills and taps if almost ANY chips or heat is not removed w/ air blast or HP coolant.

Also PTFE Teflon, in its "virgin" state. Machines like a bar of soap. It also absorps water in the air and swells. Next day your part is way OOT.

Beryllium copper (hazardous mat.) for a non-sparking wrench.

Another: Mystery metal weldment I welded. Appears the mystery metal was a high carbon tool steel. I had to scrap the whole weldment and start over after eating a few cutters. JRouche

"GAROLyTE " bearing material.....the most stinky
...offensive...lung clogging...lathe uglying...

a kind of phenolic/fiberglas/bakelite/bearing mat'l ,... which produces lung ,eye , and skin
irritation on contact...

abrasive on tools, but so are most composites ....
this one'll make you feel like you've breathd
them all.

Very high density carbon fibre, had to machine bearing holes in some for a spacecraft.

Drill would start off loverly and sharp and cut beautifully ..... by the time it got through the part it was blunt as anything and produced serious de-lamination on the back of the hole ( a no no)

oh and the dust was a bitch

Still..... in 100 yrs time , it will be the only thing I've made not in the landfil/scrapyard

Boris

the bronze rifle nut on a garner denver 83 rock drill doint know what kind of bronze it is but it eats cutters

the bronze rifle nut on a garner denver 83 rock drill doint know what kind of bronze it is but it eats cutters

the bronze rifle nut on a garner denver 83 rock drill doint know what kind of bronze it is but it eats cutters

Lets see,
BE/copper. The worst stuff to tap that there is. Sorry JR it's not HAZMAT. Covered well in a thread about a year ago.

Depleted uranium. Nasty to machine and burns.

Pure vanadium. Softer than pure lead, you can scratch with your fingernail.

Hot rolled P-20. We used to get sections over 6" thick in hot rolled and had to "de-bark".

Nitronic 50 or 60. The stuff is stress hardened and warps all over the place with a long part.

Hardened TGP shafting. Once you get throught the case, it's not bad. But then of coarse, you can't nick or scratch the rest of it.

And anything with a lot of chrome in it.
JR

Hot rolled P-20.

gawd that stuff is a doddle.... used to have to drill 1500 .030"-.040" holes 1" deep in that for PCB press tools

Boris

'kept the EDM guys busy too... sparking out the broken drills '

Pure Molybdenum........yuk!


30% glass filled valox.....takes the edge off a tool in a heart beat

CPM 10V and 15V......work hardens in a split second

Induction hardened shaft for hydraulic cylinders.

It turns fine in a lathe but putting a cross hole through it in a mill is hell. I thought I was going to bust the quill feed handle right off the mill.

TGP shafting and garolyte....2 names I never ever want to see again on a BOM in my life! done 'em both....

germanium.
MAP material.
77% and 90% pure cobalt.
monkey brains.
cats eyes.
cats brains.
anything else is a piece of cake...jim

I work with lots of delrin, which is basically PTFE...

The stuff will wrap around the stock, then fly out all over...

Plus, holding a tolerance is near impossible.

Delrin isnt teflon,lol.. it is easy to cut but makes poison gasses, so ventilation is required..

I have machined pure Beryllium..Yep, ultra poison, requires razor sharp tools and chips easier than Graphite electrodes...I still have some scrap parts around...for MX missle guidance systems..

BE/CU is toxic enough to require OSHA insections if Machined in enough Quantities.. Years back I worked in a Blow Mold shop, and we used Be/Cu for Necks and Heels, and the OSHA used to inspect Beryilluim levels in the air 4 times a year...this was in NJ in around 1989

I don't think these are anything too bad, but have machined Incanol (sp?) (not sure what grade, but lots of nickel) for an acid mixing head. Tough stuff, no fun tapping gas threads.

Also Beryllium Copper, as used for injection moulding etc years ago - this stuff does not like to be machined! It sort of tears/rips rather than machines eg screw cutting....No health warnings that I am aware of.

Modifying annealed (LOL) tooling back before carbide was readily available here, so making my own carbide drill bits (ie large) etc.

Grinding tooling made from Carpenters "KW" (for drawing work). You think you are making progress, but the only thing changing diameter is the grinding wheel....

But all good experience, right?

once had a machined workpiece made from titanium that was scrap and needed to be cut up

it was only 1"wide and .060 to .100 thick

so i went over to the shop band saw and got some beautiful chips, only there was no cutting done on the workpiece, not even touched

turned out that the titanium stripped all the teeth from the saw blade, entirely without effort
so all the neat chips laying on the table were actually the teeth from the saw blade

While its experimental, rather than production, I have machined a ceramic insert with my ultrasonic machining system:

http://members.localnet.com/~kovachic/ultrasonics.html

Eric

G9 Garolite, I refused to work with it any long after I found out what it does to you.

G9 Garolite thread

Teflon worse than machining chocolate

Heat treated 4140 55 rockwell

Anneled copper