Metal finishing Q&As since 1989

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Need suggestion for non-Magnetic steel

Q. Hello all, I'm working on a project and need some guidance. I am searching for a non-magnetic metal to replace 304 stainless. The application environment is 120 C, in 70w-140 oil, and the ID of the piece sit on a shaft rotating at 150 RPM (most have good wear resistance). Any ideas for a replacement material. Thanks

Brunno Covolan
engineer - Wylie, Texas
2007

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304 is normally non magnetic unless cold worked. Heat treatment will lower the magnetic level. Have you tried a professional degaussing unit? James Watts - Navarre, Florida 2007 If you want similar strength and hardness to 304 stainless, aluminium bronze C95400 is a good match. There are other copper alloys with much higher strength (such as high-tensile brass C86300 with tensile strength of >760 MPa (or 110,000 psi in Americanese) and yield strength of >415 MPa (60,000 psi). But you say the environment is immersed in oil, so high hardness is not necessary for wear resistance - high hardness is more important in dry abrasion applications. The phosphor bronzes are an industry standard for lubricated bearing bushes which is what your description sounds a bit like, so one of the phosphor bronzes might be quite suitable. Bill Reynolds [deceased] consultant metallurgist - Ballarat, Victoria, Australia We sadly relate the news that Bill passed away on Jan. 29, 2010. 2007

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Q. Bill
You say Phosphor Bronze for bearing bushes etc; did you mean cast or wrought PBr. I'm asking since we have had material availability problems on items for actuator components; bearing bushes, thrust washers etc, which our suppliers are recommending a change from cast Leaded Bronze and Leaded Gunmetal to cast Phoshor Bronze. Also on offer, (and cheaper) is wrought Phosphor Bronze.
Could you advise on the relative wear resistance for these applications.
Regards
Martin Rich

Martin Rich
Ship Repair - Plymouth, UK
2007

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Q. Cast/Wrought Bronze/Gunmetal equivalents and material availability problems.
We have had material availability problems on items for actuator components; bearing bushes, thrust washers etc, for which our suppliers are recommending a change from cast Leaded Bronze and Leaded Gunmetal to cast Phosphor Bronze. Also on offer,(and cheaper I suppose) is wrought Phosphor Bronze.

Could you advise on the relative wear resistances and suitability for these applications.
Regards,

Martin Rich [returning]
Technician - Plymouth UK
2007

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Non-magnetic Material for Bearing Slot

Q. I have a new product to market and need suggestions for best material for the bearing holder/sleeve. I have a 3/4" diam shaft and a standard bronze bushing over that and have placed that bronze through a SS washer pressed into the wall plate of 1/4" Al. It works but I am curious about the lifetime due to potential wear. This product is a magnetic separator for sands so these components must be non-magnetic but may be subject to dusty conditions and wear becomes an issue. What would be the best material to use for this application? The bronze can be easily replaced but the "pressed washer" needs to have a long wear life?

Mike Robinson
new manufacturer - Odessa Texas USA
September 18, 2017