Aloha, fun & authoritative answers -- no cost, no registration, no passwords, no popups
(as an eBay Partner & Amazon Affiliate we earn from qualifying purchases)

Where the
world gathers for metal finishing
Q&As since 1989

-----

Magnetic coating for stainless steel

We are designing a product which contains a sensitive spring that is immersed in drinking water (temperature between +10 °C to +75 C). The spring has to withstand these conditions for at least 10 years. Due to the requirements of the product we need to have this spring also magnetic. We first considered standard ASTM A228 spring steel as a material but this isn't magnetic enough. I was thinking that shouldn't standard nickel coating on stainless steel (like A228) increase the magnetism? Is it possible to coat A228?

Sami Lakka
Product designer - Tampere, Finland
January 31, 2011

Would an impervious plastic coating over a conventional steel spring not be an option?
G. Marrufo-Mexico

Guillermo Marrufo
Monterrey, NL, Mexico
February 4, 2011

ASTM A228 is a specification for music wire (patented, cold drawn unalloyed steel with a pearlitic microstructure, equivalent to grade DM or DH according to EN 10270-1). It is definitely ferromagnetic. Certain cold drawn stainless steel spring wire will be magnetic, due to the strain induced phase change (from austenite to martensite). Type 302 according to ASTM A313 or X10CrNi18-8 (1.4310) EN 10270-3 are the relevant standards.

Toby Padfield
Automotive supplier - Michigan, USA
February 7, 2011

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: