[GenKnot]

M12x15 = 12 mm diameter, coarse thread is assumed (1.75 mm), 15 mm (.6 in.) long

In the metric world, coarse thread is always assumed if not expressed

So, 12x15 is the same as M12x15 or M12x1.75x15 or sometimes shown as M12-1.75x15

M12x15 would not be the same as M12x1.5

Here is an example of a M14x1.5x18mm plug which would have a finer thread pitch...

Amazon.com: Votex - Made in USA - M14 x 1.5MM Stainless Steel Neodymium Magnetic Engine Oil Drain Plug - Part Number DP001 : Automotive

Buy Votex - Made in USA - M14 x 1.5MM Stainless Steel Neodymium Magnetic Engine Oil Drain Plug - Part Number DP001: Oil Drain Plugs - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

And another M12x1.5 fine pitch plug that is 11.8mm long...

Magnetic Drain Plug - Thread Size M12 x 1.50

Magnetic Drain Plug - Thread Size M12 x 1.50

www.powerslutracing.com

 

[GenKnot]

Correct. As I noted "M12x15 would not be the same as M12x1.5 "

Two different things.

 

[GenKnot]

The Amazon listing might be the correct part, but the 12x15 description is not correct. How goofy and yes confusing!

 

[GenKnot]

I like the magnetic drain plugs, so I converted all of the drain plugs in my gasoline equipment and cars using 6mm X 20mm neodymium magnets. A pack of 20 from eBay is just a few bucks. Drill a 15/64" hole using a drill press and then some JB weld. The magnets are practically a press fit, so the epoxy is not having to do very much.
I put a few slight divots in the magnet with my grinder just to give the epoxy something to hold onto. Also, one long score on one side (equal to the depth of the hole) to allow the excess epoxy to ooze out as they are inserted using a vise and a wood block to press them in.
Just make sure there are not any whirly parts inside the block that might hit the magnet. None of my installs have had an issue with that and they have been in there for many years now.