What size magnets

[IvanW]

I need to purchase some magnets that are strong enough to hold through 3/4" glass. How do you determine what pull force to buy. They are to hold a fish acclimation box.

 

[webmanny]

You should get at least 20mm rounds by 10mm thick. If you get N52 Neodymium magnets, these will have about 19 pounds of pull force each. 4 magnets should be sufficient to hold any fish box inside the aquarium over 3/4" material.

I use these to build float switch and dosing lines holders that I used to sell on ebay and they work great. See below the picture of the ones I make encased in epoxy (You have to encase it) holding great on a 3/4" acrylic piece.

Good luck.

 

[IvanW]

Do you have any links to suppliers,I know there are dozens online, sometimes recommendations are the way to go.

 

[webmanny]

Yep. Newegg has them at a good price for a USA company.

Link

 

[IvanW]

Thanks

 

[webmanny]

This is another option with the pull force information that you asked for. It turns out I was under selling these. They actually have about 35 pounds of pull force.

LINK

 

[dahc3dee]

You should get at least 20mm rounds by 10mm thick. If you get N52 Neodymium magnets, these will have about 19 pounds of pull force each. 4 magnets should be sufficient to hold any fish box inside the aquarium over 3/4" material.

I use these to build float switch and dosing lines holders that I used to sell on ebay and they work great. See below the picture of the ones I make encased in epoxy (You have to encase it) holding great on a 3/4" acrylic piece.

Good luck.

Do you use coated magnets or “bare” N52 magnets in a 3D printed application?? I just tried 2 magnets with 80lb pull force with my 3/4” thick tank glass and got nothing. They couldn’t hold their own weight up (but they were also “epoxy coated” so I don’t know if that did anything to counteract the magnetic force).