Demonstrate eddy current braking to get a better understanding of how a roller coaster can go from 200km/h (125mph) down to a crawl in seconds without a physical brake. This 25x20mm comes with a pull force of 56 lbs suitable for demanding applications.
Our biggest disc is ideal for simulating eddy current braking. Drop it down a 1" diameter copper or aluminum pipe & be amazed. See the video below. Don't have a 1" copper pipe?. You can also do this with a 1/2" pipe using our 10x25mm, 12.5x12.5mm or 12x25mm rod magnets.
We have sold NdFeB magnets since 1996 and N42 grade since 2003, the best value for strength & temperature vs cost. Don't be fooled by claims of higher strength, N52, at lower cost.
Read the complete Google Customer Review for: "...(Indigo) N42 Neodymium magnets...the real deal…bought magnets on Amazon advertised as N52… another cheap Chinese fake"
We also provide complete Documentation including MSDS & ROHS; see below.
The Mark II Magnaprobe is an excellent tool for detecting magnetic fields & is must for any college or high school electricity & magnetism lab. See it in action below in our eddy current-drop tower braking simulation or read our blog Eddy Current Copper Tube Drop Tower Brake Test.
Even more impressive is the ultrasensitive Mark I Magnaprobe which responds to magnetic fields as weak as 0.3 gauss. A must if your cyclotron or particle collider is slightly off. In this instance, it was able to detect the eddy current in the simulation below at a distance of over 1m (3.3 feet)!
Want to spend less and really get your best bang for the buck? Here are reviews some customers did on our Google pages.
Ron Bennett: Fantastic support and product. Beats Amazon price with real customer service. After online order was placed, they called and and asked if I had any questions and gave clear instructions on pickup process. Order was ready and in stock and the product was of the highest quality and exactly...
Tracy Myerson: Super fast shipping, excellent prices, and great quality product! I purchased N42 Neodymium magnets, they are the real deal. I had previously bought magnets on Amazon that were advertised as N52, they were just another cheap Chinese fake. These folks sell authentic, high quality....
Ian Kelly: I've dealt with Indigo Instruments for years now. They have always been personable and very knowledgeable. Most recently I sent them a hand-drawn sketch of my interpretation of something I saw on YouTube and wanted recommendations....I couldn't be happier...
Specifications
Magnet Characteristics
Field Strength (Gauss) & Pull Force in Pounds & Kilograms at 5 Distances Above Magnet
SKU: 44209-20 Size: 25 × 20mm
Distance (mm):
0
0.1
1
10
100
Gauss
5596.8
5551.8
5145.0
1969.3
15.4
Lb
54.58
53.71
46.12
6.76
0.00
Kg
24.81
24.41
20.97
3.07
0.00
Click on N42 Magnet Specifications for a table that lists general characteristics such as coercivity & remanence.
Click on N42 Magnet Tolerances for a table that lists the range of variation in thickness, diameter, etc.
Click on American vs Metric to see a table with conversions & as well as rounded mm equivalents closest to inch sizes.
Documentation
Magnet Documentation
Drawing
Compliance
MSDS
ROHS
Graph
REACH
Reviews (1)
2018-07-05
Quick delivery.
Well packed.
Magnets are plated with slightly rounded corners.
Very nice product.
Pushed two magnets face to face. Opposing force was 50 lbs.
— Roman
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