Well since the main alloy is Nickle (75% or greater) I would take a piece and try drilling a hole in it. Just use a decent quality HHS drill bit that is sharp. If it trashes the drill bit it's Mu Metal. If you have never drilled, milled or turned a high nickle alloy consider yourself lucky. You need the best cutting tools made to penetrate this alloy.
BillWojo
BillWojo
As a sheet metal it will shear, bend and punch like mild steel. With a nickle content of over 70% it machines terribly. We had some some Hastalloy come through the shop one day,it's about 50% nickle content, a sheet metal job. Easy to work with as sheet metal, a few months later a lathe job came in as a quote. I refused it and the shop foreman was giving me crap about being afraid to machine it. After listening to him bust my chops I grabbed a piece of left over sheet metal and several 1/8 split point cobalt drills, really good ones. Told him to drill a hole for me. He burnt up all three drill bits and gave up. All he did was make shiny spots on the metal. I passed the quote on to 4 other machine shops and they all came back as a "no quote".
BillWojo
BillWojo
cdbd, Billwojo,
It can't be both a soft nickel alloy hard as mild steel and also trash a good HSS Made in USA drill bit.
A few years back I bought a "nice" set of Ti coated drill bits from the well known wood working store. As the store is well known and known for quality stuff I bought the set thinking I'll have these forever, etc. Two types of bits in the set, brad point and standard point.
I went to drill a hole in a thin piece of (90 degree) sheet metal to mount it on wood and screw the corners together. I couldn't believe what scheisse bits these were, the damn bits bent around like a twisty drink straw that kids use. I did it to two of them, then just put the box of them away never to be used again.
I used my old set of USA made steel bits and never looked back. I also took the time to head over to my local machine shop surplus store and filled out some of the old drill index boxes that I got at a garage sale. I've got 4 sets of good USA made complete drill
indexes now. One of them is with the big sized bits too.
Cheers,
It can't be both a soft nickel alloy hard as mild steel and also trash a good HSS Made in USA drill bit.
A few years back I bought a "nice" set of Ti coated drill bits from the well known wood working store. As the store is well known and known for quality stuff I bought the set thinking I'll have these forever, etc. Two types of bits in the set, brad point and standard point.
I went to drill a hole in a thin piece of (90 degree) sheet metal to mount it on wood and screw the corners together. I couldn't believe what scheisse bits these were, the damn bits bent around like a twisty drink straw that kids use. I did it to two of them, then just put the box of them away never to be used again.
I used my old set of USA made steel bits and never looked back. I also took the time to head over to my local machine shop surplus store and filled out some of the old drill index boxes that I got at a garage sale. I've got 4 sets of good USA made complete drill
indexes now. One of them is with the big sized bits too.
Cheers,
Sync, look at a machining table for the relative ease of machining different materials. If mild steel (1018) is factored at 100% my guess is that Mu Metal will be below 10%. Being soft and malleable has nothing to do with how it machines. Nickle based metals are a nightmare to machine. There is a reason nobody including me would quote that Hastolly job. Unless you work with those alloys on a regular basis you don't have the knowledge or proper tools to machine it. From my limited experience I can tell you that the cutting speed must be slowed way, way down and it is imperative to get the cutting edge to penetrate the moment the edge touches the metal and keep a chip flowing. If the cutting tool rubs at all the metal forms a glass hard surface, the tool dulls and it's next to impossible to get through the hard surface again. It's called work hardening.
Typically to quote a machining job in a high nickle based alloy figure if you quote it as 304 stainless steel and than multiply your quote by a factor of 5 to 10 you might not lose your shirt. Scrap a 100 lb bar of Hastolly and your done. Easy to do. Carbide insert tooling is the name of the game here and you will go through a LOT of expensive inserts.
As far as drill bits, the minimum quality I will buy is USA made high cobalt 135 degree split point drills. Precision Twist Drill brand is decent quality. My foreman had 3 of them to try and drill a hole and they would have worked but he ran the drills as if he was drilling stainless steel, way, way to fast. As soon as he touched the Hastolloy it took the edge off and just rubbed.
Drilling 304 stainless steel is a walk in the park but than it has a much lower nickle content.
So being as soft as mild steel has nothing to do with how it machines.
BillWojo
Typically to quote a machining job in a high nickle based alloy figure if you quote it as 304 stainless steel and than multiply your quote by a factor of 5 to 10 you might not lose your shirt. Scrap a 100 lb bar of Hastolly and your done. Easy to do. Carbide insert tooling is the name of the game here and you will go through a LOT of expensive inserts.
As far as drill bits, the minimum quality I will buy is USA made high cobalt 135 degree split point drills. Precision Twist Drill brand is decent quality. My foreman had 3 of them to try and drill a hole and they would have worked but he ran the drills as if he was drilling stainless steel, way, way to fast. As soon as he touched the Hastolloy it took the edge off and just rubbed.
Drilling 304 stainless steel is a walk in the park but than it has a much lower nickle content.
So being as soft as mild steel has nothing to do with how it machines.
BillWojo
According to a manufacturer of Mu Metal, it is similar to 300 series stainless steel:
http://www.magnetic-shield.com/pdf/...sign_considerations_fabricating_shielding.pdf
http://www.magnetic-shield.com/pdf/...sign_considerations_fabricating_shielding.pdf
That link is interesting but no where does it mention machining. Forming, shearing, bending and punching, yes but none of those processes produce chips. It is similar to 300 series stainless in it's forming and stamping characteristics.
Now grab a drill and make a hole in the stuff. High nickle alloys are a total bitch to machine, ask any machinist.
BillWojo
Now grab a drill and make a hole in the stuff. High nickle alloys are a total bitch to machine, ask any machinist.
BillWojo
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