Rerurn to Romy the Cat's Site
In the Forum: Analog Playback
In the Thread: Copper Mat on a Micro Seiki Gun Metal Platter
Post Subject: 316L magnetism and platter drawingPosted by Wellington on: 8/23/2017
Measet,
As you may know, 316L is a low-carbon austenitic stainless steel which has superior corrosion as well as machining and welding properties. It is generally non-magnetic in the raw state, but cold working can convert tiny amounts of its austenite to martensite, which is slightly magnetic.
I checked my platter again today with a small but very powerful neodymium magnet. It does barely attract to the platter, but far, far less than to regular steel. I can no longer feel any pull at all with the copper CU-180 mat on top of the platter, separating the magnet from the platter. I do not worry about it.
Ironically (and that's a pun as you will see), this magnet pulls stronger to the black speckled granite slabs that my RX-5000 sit on. Yep, there must be iron flakes inside the granite, and these attract the magnet more than a 50-pound chunk of 316L!
I will try try to attach a drawing of my platter design. The drawing assumes you know or can measure the other dimensions of the original platter. The angled underside surface reduces the bell-like ringing mode of the original design, as well as increasing mass.
Rerurn to Romy the Cat's Site