Does anybody of you have a experience machining Nihard casting at 550BHN hardness. I have a pump casing weight 32Kgs, 14" in dia and 6" long. My customer whants the seal area dia of 3.250" to be machined within +/-0.003" and a 12" dia within +/-0.005". I have never done this on a direct Nihard castings,but with machinable metal inserts.
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Machining Nihard castings
- Thread starter Yogesh
- Start date
- Replies 7
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precisionworks
Diamond
- Joined
- Apr 20, 2005
- Location
- Benton, IL USA
550 Brinell is equal to about 55HRc. Some of the Ni-Hard alloys are over 700BHn, so yours is machinable with the correct tooling.
Ceramic or Cermet inserts would be the least expensive choice.
Superabrasives are the next step up. These include Cubic boron nitride (CBN), Polycrystalline diamond (PCD), and a combination of the two called Polycrystalline cubic boron nitride (PCBN). PCBN inserts are designed for machining Ni-hard cast iron, hardened cast iron, high chrome alloy steels, and pearlitic gray cast iron.
Check with your insert supplier. They should be able to recommend an insert for this material.
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Barry Milton
Ceramic or Cermet inserts would be the least expensive choice.
Superabrasives are the next step up. These include Cubic boron nitride (CBN), Polycrystalline diamond (PCD), and a combination of the two called Polycrystalline cubic boron nitride (PCBN). PCBN inserts are designed for machining Ni-hard cast iron, hardened cast iron, high chrome alloy steels, and pearlitic gray cast iron.
Check with your insert supplier. They should be able to recommend an insert for this material.
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Barry Milton
Thanks Barry, I have tried with some ceramic and CBN, but the problem is the casting has a step out on the face. This gives a intermittent cut and hammered on the tool, so inserts are breaking rather then wear.
I have been suggested by another expert on this forum for spindle grinding, maybe with a tool post grinding attachment
I have been suggested by another expert on this forum for spindle grinding, maybe with a tool post grinding attachment
mohit.adlakha
Plastic
- Joined
- Apr 8, 2016
Hey man, Im mohit from Mumbai.
What all machines do you have ?
What all machines do you have ?
Rafael Martinez
Plastic
- Joined
- Feb 16, 2022
Try PCBN500 or 600 it’s for tough for interrupted applications, around 380 SFM at .100-.075 radial DOC and .011-.009 Per rev.
However, you need to be careful of blowholes, and grind any high spots as they may be sand spots.
However, you need to be careful of blowholes, and grind any high spots as they may be sand spots.
Illinoyance
Stainless
- Joined
- Aug 24, 2015
Milland
Diamond
- Joined
- Jul 6, 2006
- Location
- Hillsboro, New Hampshire
15+ year old thread, back from the dead in 2016, and now.
Maybe the OP is reading this and can give us an update on how he did?
Maybe the OP is reading this and can give us an update on how he did?
