N35 NdFeB Disc Countersunk ​Magnet D25mm*6mm-5.2mm

Specification of N35 NdFeB Disc Countersunk Magnet D25mm*6mm-5.2mm
Texture of material	N35
Remanence br	1.197T 11.97KGs
Coercivity HCB	918.2 kA/m 11.54kOe
Intrinsic coercivity Hcj	1097 kA/m 13.78kOe
Maximum magnetic energy product (BH) max	34.67MGOe
Size	Diameter D25 mm * thickness 6 mm – middle hole 5.2 mm
Tolerance	The diameter is ± 0.05mm and the thickness is ± 0.1mm
Coating	Nickel copper nickel
Magnetization direction	Axial magnetization
Surface magnetic field	2940GS
Pull	6.7kg
Working temperature	The maximum working temperature is 80 ℃
Single weight	20.4g

Magnetic Characteristics of N35

Br (Residual Induction)	Br (Residual Induction)	Hcb (Coercive Force)	Hcb (Coercive Force)	Bhmax (Maximum Product Energy)	Bhmax (Maximum Product Energy)	Hcj (Intrinsic Coercive Force)	Hcj (Intrinsic Coercive Force)
mT	KGs	KA/m	KOe	KJ/m³	MGOe	KOe	KA/m
1.18-1.23	11.8-12.3	868	10.9	263-287	33-36	12	955

Thermal Characteristics of N35

Max Operating Temp	Curie Temp	Reversible Temp Coeff	Rev Temp Coeff
°C	%/°C	Br (TC a(Br) %/°C)	Hcj (Tc a(Hcj) %/°C)
80	310	-0.12	-0.75

Mechanical/Physical Characteristics of N35

Density

g/cm3

7.5-7.8

Grade & Working Temperature:	Grade	Max Operating Temperatures
	N35-N50	80°C     (176°F)
	35M-48M	100°C   (212°F)
	35H-45H	120°C   (248°F)
	33SH-42SH	150°C   (302°F)
	28UH-38UH	180°C   (356°F)

Neodymium Special Shaped Magnets with other Coating are also available:

Coating Type	Overall Thickness	Salt Spray Test	Pressure Cooker Test
Ni-Cu-Ni (Nickel)	15-21 μm	24 hours	48 hours
NiCu + Black Nickel	15-21 μm	24 hours	48 hours
NiCuNi + Epoxy	20-28 μm	48 hours	72 hours
NiCuNi + Gold	16-23 μm	36 hours	72 hours
NiCuNi + Silver	16-23 μm	24 hours	48 hours
Zinc	7-15 μm	12 hours	24 hours

Each individual layer of Nickel and Copper are 5-7 μm thick. The Gold and Silver Coating layers are 1-2 μm thick. Test results shown to allow comparison between Coating options. Performance in your application under your specific test conditions may vary. Salt Spray testing conducted with a 5% NaCl solution, at 35°C. Pressure Cooker Test (PCT) conducted at 2 atm, 120°C at 100% RH.

Shape	Max Size	Min Size
Block	L240*100*50mm	L1*1*0.5mm
Disc/Cylinder	D240*50mm	D1*0.5mm
Ring	OD240*40mm (hole size flexible as requested)	D1.5*0.5*1mm
Countersunk	OD240*40mm (hole size flexible as requested)	D8*2.5mm (hole size as customized)
Other special shapes	per as your request	per as your request

How to detect the quality of disc countersunk magnet?

The quality of strong NdFeB magnet is evaluated from two aspects: 1. Product performance; 2. Product appearance.

Product performance

There is a unified standard for the properties of Nd-Fe-B. the main indexes include magnetic energy product, coercivity and remanence.

Product appearance

Appearance inspection can be divided into five categories:

• 1. Scratches (including scratches, line marks, knife marks, etc.);

• 2. Pockmarks (including pockmarks, pockmarks, bubbles, scars, slag layer, local thickness, electroplating tumor);

• 3. Cracks (including cracks, cracks, etc.);

• 4. Edge chipping (including edge chipping, edge chipping and material residue);

• 5. Sand hole (including sand hole, air hole, pinhole, particle, etc.) to see whether there are missing edges and corners, whether the electroplated coating is in good condition, and whether the size meets the design requirements; Neodymium iron boron is generally electrodeposited to protect it from corrosion and rust. It is usually placed on a plane that can be adsorbed with a magnet of the same specification, such as a patch, blade, iron door, etc. the size of the magnetic force can be distinguished by the hand feeling.

Testing method of NdFeB disc countersunk magnet

• 1. For the products provided by the new supplier, according to the drawing requirements, first measure the overall dimension, and then measure the magnetic induction intensity with Gauss meter according to the brand of the magnet to check whether it is within the required range. Whether the magnetization direction is correct.
• 2. Conduct temperature rise and demagnetization test for 3-5 samples, mark three positions on each magnet, measure the magnetic induction strength of each magnet at three positions at room temperature, then put the magnet into the high temperature box, set the temperature at 75 ℃ and heat it at high temperature for 1 hour, then take out the magnet to measure the magnetic induction strength of the same three positions, make a record, cool it to room temperature, and then measure it in turn. Then set the temperature of high temperature box to 85 ℃ and 95 ℃ for measurement respectively, and the measurement method is the same as that of 75 ℃.
• 3. Check the measurement statistics, the demagnetization amount is less than 1% at 85 ℃
• 4. The salt spray test has been done by the supplier and the test report has been provided. The test time is more than 48 hours.
• 5. For the magnets used in batches, the appearance and dimension, magnetic induction strength of each batch shall be inspected to ensure the consistency within the batch: the open circuit magnetic flux is less than 2%, and the magnetic flux between batches is less than 3%
• 6. Several important technical parameters of magnets, such as coercivity, intrinsic coercivity and remanence, can not be measured. In the past, the supplier provided the testing parameters, and in the future, we can take a few pieces of each batch to a special testing agency for inspection.

Detection tools used

Micrometer, vernier caliper, Gauss meter, fluxmeter, film thickness meter and other measuring tools are generally used in the detection of finished NdFeB magnets.
The film thickness meter mainly measures the plating layer thickness of NdFeB magnet. The film thickness meter can effectively monitor the plating quality and flexibly adjust the magnet plating.
Micrometer and vernier caliper are mainly used to measure the tolerance of NdFeB magnet. The unit is mm.
Gauss meter is mainly used to measure the magnetic force of a point on the surface of the magnet, unit Gauss. Because the magnetic force of each point on the surface of the magnet is different, and the edge magnetic force is higher than that of the center point, the measured data error is too large.
Fluxmeter mainly measures the magnetic force of one side of NdFeB magnet, in Weber WB. Compared with Gauss meter, fluxmeter measures more objective and accurate data.

China Disc Countersunk Magnets Manufacturer www.rizinia.com supplies N35 NdFeB disc countersunk magnets, block countersunk magnets,arc countersunk magnets for scientific experiments or for industrial applications.

This product is not a toy and is not to be used by children. This product is to be used for scientific experiments or for industrial applications. This product contains strong Neodymium magnet(s) that can be harmful or fatal if swallowed. Strong Neodymium magnets are fragile, they are brittle and will break or chip if they hit a hard surface or are snagged together. Always use the utmost care when handling Neodymium magnets.