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Is Type 17-4PH Stainless Steel Magnetic?

Q. Hi, HooiPeng Cheah,
Did you find the answer to your question? I also want non-magnetic version of 17-4 PH in any condition from H1025, H900 etc.


Tejesh Chimegave
Technical Lead - Bengaluru, India
May 4, 2022

A. Hi Tejesh. The way I read it is that 17-7 PH is by definition a "semi-austenitic" stainless steel, less magnetic than some, but inherently magnetic. Four readers more knowledgable than me, going back to 2005, have explained that it is not non-magnetic.

None of countless thousands of readers have yet contradicted this claim in 17 years now, so if you want non-magnetic, apparently 17-7 PH is not the right choice.

Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
May 2022

⇩ Related postings, oldest first ⇩

Q. Could you please advise the magnetic properties of Type 17-4PH Stainless Steel - i.e. in relation to iron.

Is it easy to distinguish between Type 17-4PH and Iron by a simple test of magnetic properties?

The reason for my inquiry is that a manufacturer's drawing specifies 17-4PH as a material for a 100 mm diameter by 300 mm long load pin, and our customer reports that it appears highly magnetic when offered up to a magnetic clamping table.

Also the product has been electropolished - which seems unnecessary for stainless steel.

Thank you in anticipation,

Brian Palmer
- St Ives, New South Wales, Australia

simultaneous replies 2005

A. It's a martensitic stainless steel, and its magnetic attraction properties are similar to mild steel.

Electropolishing will enhance the resistance of the surface to corrosion. Whether it's a SIGNIFICANT enhancement depends on the surface finish before electropolishing, and on the service environment, and whether the component is still considered serviceable after some corrosion has occurred.

Bill Reynolds
Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.

A. 17-4 PH SST is magnetic. it is a Hi chrome and SST whereas the NON magnetic type, i.e., 300 types have high amount of nickel in it.

Chris Snyder
plater - Charlotte, North Carolina

April 21, 2009

Q. I'm HP Cheah a machining parts manufacturer from Penang, Malaysia.
Our customer had given us a fixture and claimed that it was made from 17-4PH Stainless Steel and we made the fixture from the print and the requested material.
We submitted the samples and were rejected because our fixture can be easily magnetised even after being demagnetised.
Truly enough, we tested their sample and no matter how many times we stroke a permanent magnet over it the readings from our Tesla meter only shown 0.1 to 2.0 T whereas our will have more than 20 T. The specification called for below 15 T.

Is there any 17-4PH that is non-magnetic or some other material of the same properties in the market?
The 17-4PH material we are using is of condition H900.


HooiPeng Cheah
Industrialist - Bukit Mertajam, Penang, Malaysia

Q. Please reply the question.

Saraswathy symachellam
- malaysia
May 19, 2009

A. There is no grade (or supply state) of 17-4PH which is not able to be magnetised quite strongly.

Andrew Troup
- Chch, New Zealand
May 31, 2009

A. All 17-4PH exhibits paramagnetic properties. How magnetic has to do with how it's manufactured, what tools are used to cut it etc. Regardless, it can easily be magnetised even in the best case.

Josh Luther
Medical Manufacturing - Sarasota, Florida, USA
June 14, 2013

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