I need to know what strength rare earth magnets I will need to hold a sun shade made of shadecloth to a windshield of a RV. they will be on both side
1763105
As the magnets are working through glass(I think that is what you mean when you say both sides) and also dealing with wind and the elements, I would suggest nothing thinner then a 1/4" thick. You would probably get more strength with a block magnet then a disc if the rectangular shape would work for you.
1351046
These are pretty powerful magnets.. The magnets are at my grandson's house and I could go over tomorrow and check it out for you...
915849
Absolutely! These rare earth magnets are powerful enough to support the weight of a standard size elephant but gentle enough that you will be able to lift them off once they attach. I have also used them when I bungee jump to attach the bungee to the deck that I am jumping off. Then when I am at the bottom my friends just lift the magnet off.
1666807
Well, you would have to have the polar opposite of this magnet for those to work with what you want. You might be better off using just a piece of metal available at your local hardware store (Home Depot).
374172
Not even close. The magnet itself is about 10 ounces; the entire magnet structure (magnet, pole pieces, and shorting ring), perhaps 20. But really, weight doesn't matter so much as flux strength. Speaker makers use more advanced magnetic materials than they did in the 70s, so today's modern rare-earth ferrites can be as strong or stronger than the "40 ounce" magnets of yore. A smaller magnet also makes the speaker easier to install (less clearance space needed) and saves weight, which improves the handling and economy of your car! And to expand that answer still further, magnet strength is only part of the picture. There's also the construction of the voice coil (core material, wire gauge and shape, sintering and enameling, etc.), the shape and material of the cone (conic vs. parabolic vs. hyperbolic, paper or polypropylene or fiberglass or metal, isotropic vs. anisotropic, etc., etc.), and the materials and construction of the surround and spider. Really, to get a clearer picture, look at the T-S parameters (Fs, Qts, Vas). Ideally, for a car speaker: Fs--Resonance frequency; lower is better. Qts--The total 'Q factor' or 'peakishness' of that resonance. For most car speakers, operating in a more-or-less 'infinite baffle' configuration, this should be around 0.7 or so. A higher Q (above 1.0) will give "boomy" bass; lower Q (below 0.5 or so) will require a separate box for best results. Vas--The free air equivalent volume. If these speakers are going in your rear deck, then the Vas for each speaker should be no larger than half the volume of your trunk (remember, they're in pairs) or "boomy," sloppy bass will result.
403206
No I don't, but I use a lot of bungie cords, different sizes from 3/16, 3/8, & 7/16, and all of them are strong, never broke any! I'm assuming 1/2 inch would pull a car if you needed to? I'm sure it will meet your need. I used 3/8 & 7/16 to hold a tarp down on the top of a 10 X 20 building and they lasted over 6 months. Ken Hockin Alvin, Texas
482439
It's an extremely powerful magnet. I don't have a tarp to test it out but my strong sense is if you got a few of these they'd hold a tarp down easily. But remember there's a lot of "non-metal" material in cars these days. Just sayin...
1650206
I have looked this up as I do not know and have this Material: Grade N50 neodymium magnets. Patent licensed. Gauss Rating: 14,200 Gauss Holding Power: 10 lbs Pole Orientation: Axially magnetized, i.e. the N and S poles are on the flat surfaces Applications: holding, crafting and science projects
2108829
Good questionThere preety strongBeing from long island I would have to say yes I think there strong enough for a sun shade on a sailboat under moderate wind conditions
972705
Rare earth magnets MAY work. I never had any luck, though, I think my can was old and no amount of stirring helped. I went with a piece of sheet metal instead.
1467174
Sorry, wish I could help. I bought those for my grand daughter who is into rock collecting. The ones I got are very nice, and they may look good as sun catchers, but we have not held them up to the light nor a window.
1485126
From my experience, two part epoxy is the best. if on a shiny surface to which the glue is not bonding to, I would recommend taking some sand paper and rough up the surface then glue the magnets on
394894
i put the strongest magnet i have on the frame and handle. the frame is aluminum. the handle is mostly aluminum but has something else in it because the magnet is slightly attracted to it but won't stay attached.
1462284
The magnet is pretty strong, but I would not bet on them staying attached when you close the trunk lid. Adding some two sided tape to the bottom might work, but the magnet would not sit flush with the metal, so you would be mostly relying on the strength of the tape to hold the light on the trunk lid. I'd give it about a 75% chance of working!!
2000967
These magnets were pretty strong. They may be too large in diameter to use on a name-tag. When I stuck two together without the spacer, they were incredibly hard to separate. I would recommend a rigid backer for the name-tag (otherwise you may get too much flex and peel on the edge of the magnet, between the magnet and the cloth (as you pull the tag away) and end up "peeling the magnet" off of the cloth. I used these to actually glue to another, weaker refrigerator magnet I had. I found the poles and got the strongest side to the refrigerator and used a surface insensitive super glue to bond them together. Since I don't take them on/off the fridge a lot, it seem to be holding so far. You may be able to use a hot-melt Hobby glue from Michael's too bond to the cloth, but I might suggest using the smaller, 1/2" version of these. I believe I've seen plastic tags that actually have a "Magnet Bar" with two 1/2" diameter magnets glued to a piece of metal and then the plastic piece has a metal bar glued to the back of that. When you wear the name tag, the magnets get "Sandwiched" between the two pieces of metal but the way they are attracted, the metal bar acts kind of like a "handle" when you take it off. If you search "Magnetic Name Badges" you will probably be able to find a picture of what I'm describing.
166064
it is triangular and in ech corner has a metal ring.I threaded a very strong cord through each and attached the ends to secure objects like a wall mounted very secure ring. The other two cords are attached to securely embedded garden railings. They need to be secure because it is best to have the cords very tight so the wind dose not fill the coolabar and look like a ship sail and blow away. good luck. have just shifted mine to make the shade in best possible position when sun is at it strongest. 35' C in Greece.
1831054
The magnets you would use to attach this to a refrigerator are neodymium ring magnets like these 10 Neodymium Magnets 3/4 x 1/4 x 1/8 inch Ring N48 or these 10 Neodymium Magnets 3/4 x 1/2 x 1/8 inch Ring N48. You can also find bar magnets with pre-drilled holes but they likely will be too large and stronger than you want for this purpose. Two things you should know about these if you have never used rare earth magnets: first, they are far, far stronger than any other magnet type the average person has come across in their lifetime and can easily injure yourself (I have used the first size linked above and had several blood blisters and pinched the skin off my fingers to prove this is true). The other thing to know is that like much weaker ceramic magnets, they are brittle and you cannot easily drill your own holes in these without them crumbling apart. That is why you need the ring magnets instead of disks (unless you can insert the disks into a compartment or internal space without using a screw) for the knife holder. The ring magnets are also more versatile and fun than the disks since you can stack the left over ones on a straw and watch them float three or four inches apart. Lastly, brass screws will not be magnetic and easier to use with these.