China Best N48 Od50.8xid3.2X6.4mm NdFeB Permanent Ring Magnet

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Samarium Cobalt magnets, also known as rare earth magnets, offer the best value when comparing performance and size in high temperature or adverse environments.

Samarium Cobalt magnets are higher in cost, specially ring samarium cobalt ring magnet, but magnetically very strong and typically allow for dimensional reductions with higher precision.

GME can supply Samarium Cobalt Magnets with custom shapes and sizes, made-to-order Samarium Cobalt Magnets, or we can assist in developing a solution specifically for your application.

Best N48 OD50.8xID3.2x6.4mm ndfeb permanent ring magnet

Diameter:OD 2"Diameter:ID 1/8"Height:1/4"Magnetization:Through ThicknessPlating/CoatingNickel (Ni)RallyForce:45.87poundsGradeN48Br13.6-14.2KGHcb≥10.5KOeHci≥11KOeBHmax45-48 MGOeTmax80C / 176F MOQ1000pcsLeading Time18-23 working daysSampleYesCertificateISO2000, TS16949, RoHS, CE & SGSPaymentT/T, PayPal, Western Union

Samarium Cobatl magnets: good thermal stability, resistant to corrosion, resistant to demagnetization
A samarium-cobalt (SmCo) magnet, a type of rare earth magnet, is a strong permanent magnet made of an alloy of samarium and cobalt.
They are generally ranked similarly in strength to neodymium magnets, but have higher temperature ratings and higher coercivity.
samarium-cobalt (SmCo) magnets are brittle, and prone to cracking and chipping. Samarium-cobalt magnets have maximum energy products (BHmax) that range from 16 megagauss-oersteds (MGOe) to 33 MGOe, approx. 128 kJ/m3 to 264 kJ/m3; their theoretical limit is 34 MGOe, about 272 kJ/m3.
samarium-cobalt (SmCo) magnets are available in two "series", namely Series 1:5 and Series 2:17.
Sintered Samarium Cobalt magnets exhibit magnetic anisotropy, meaning they can only be magnetized in the axis of their magnetic orientation. This is done by aligning the crystal structure of the material during the manufacturing process.

Machining & Magnetization
Samarium Cobalt magnets offer strong resistance to demagnetization. All Samarium Cobalt magnets cannot be formed with conventional drilling, turning or milling processes, and must be ground before they are magnetized. Additionally, large or complex assemblies are usually magnetized prior to assembly. Standard tolerances for Samarium Cobalt magnets are +/-.005 for ground dimensions.
1:5 alloy material
1:5 offers 16 MGOe (energy product) to 22 MGOe and is made up of approximately 50% samarium and 50% cobalt. The 1:5 series has a maximum recommended operating temperature of 250°C. SmCo 1:5 magnets require lower field strengths than 2:17 materials to magnetize. In some instances, 1:5 material may be magnetized with multiple poles, provided that a magnetizing fixture is available.
2:17 alloy material
2:17 offers 24 MGOe to 32 MGOe and is composed of about 25% samarium, 5% copper, 18% iron, 2% hafnium or zirconium, with the remainder being cobalt. The 2:17 series has a maximum operating temperature of 350°C. Special grades of 2:17 are available which can operate to even higher temperatures. SmCo 2:17 requires a higher magnetizing field than alloy 1:5 does, and multiple pole magnetization is sometimes possible, provided that a magnetizing fixture is available.
Performance for samarium cobalt magnets:

MaterialGradeRemannenceCoercive ForceInstrinsic CoerciveMax EnergyDensityTemp
CoefficientTemp
CoefficientCuire TempMax Working Temp.
(TW)(Br)(Hcj)(Hcb)(BHmax)(D)(Near Br)(Near Hcj)(TC)mTGsKA/mOeKA/nOeKJ/m3MGOeg/cm3%/K%/KºCºCSmCo 1:5
SmCo1884084006057600143218000143188.1-0.04-0.3750250(SmPr)CO5SmCo2089089006378000143218000159208.2-0.04-0.3750250 SmCo2293093006378000143218000175228.2-0.04-0.3750250 LTc(HM-10)59063049362001430183080108.2Temp Range%ºC7002501:5 20-100ºC-0.004 (SmGd)CO5 100-200ºC-0.021 200-300ºC-0.042
SmCo2498098006768500143218000191248.3-0.03-0.2800280 SmCo24H98098006768500198925000191248.3-0.03-0.2800280 SmCo26L10301030039850004385500207268.3-0.03-0.2800300 SmCo261030103007169000119415000207268.3-0.03-0.28003002:17 Sm2SmCo26M1030103007169000159220000207268.3-0.03-0.2800300(CoFeCUZr)17SmCo26H1030103007169000198925000207268.3-0.03-0.2800350 SmCo281070107007569500119415000223288.3-0.03-0.2800350 SmCo28M1070107007569500159220000223288.3-0.03-0.2800350 SmCo301100110007729700119415000239308.3-0.03-0.2800350 SmCo30M1100110007729700159220000239308.3-0.03-0.2800350 LTc(HMG-22)98098007159000150020000230238.3Temp Range%ºC8403002:17 -50-25ºC0.005 (SmEr)2(CoTM)17 20-100ºC0.012 100-200ºC0.006 200-300ºC-0.025

Features include:
Samarium cobalt magnets are hard and brittle and may chip or break if dropped.
They have high magnetic properties
Samarium cobalt magnets offer good thermal stability
Samarium cobalt magnets are resistant to corrosion
Samarium cobalt magnets resistant to demagnetization

Advantages:Extremely resistant to demagnetizationhigh temperature stability (max operating temperatures between 250 °C (523 K) and 550 °C (823 K); Curie temperatures from 700 °C (973 K) to 800 °C (1,070 K)Expensive and subject to price fluctuations (cobalt is market price sensitive)Disadvantages:Samarium cobalt magnets can easily chip; eye protection must be worn when handling them.Allowing magnets to snap together can cause the magnets to shatter, which can cause a potential hazard.Samarium-cobalt is manufactured by a process called sintering, and as with all sintered materials, inherent cracks are very possible. These magnets do not have mechanical integrity; instead the magnet must be utilized for its magnetic functions and other mechanical systems must be designed to provide the mechanical reliability of the system.Comparison between neodymium and samarium cobalt

PropertyNeodymiumSm-CoRemanence (T)1-1.30.82-1.16Coercivity (MA/m)0.875-1.990.493-1.59Relative permeability1.051.05Temperature coefficient of remanence (%/K)0.120.03Temperature coefficient of coercivity (%/K)0.55..-0.650.15..-0.30Curie temperature (°C)320800Density (g/cm3)7.3-7.58.2-8.4CTE, magnetizing direction (1/K)5.2x1065.2x106CTE, normal to magnetizing direction (1/K)0.8x10611x106Flexural strength (N/mm2)250150Compressive strength (N/mm2)1100800Tensile strength (N/mm2)7535Vickers hardness (HV)550-650500-650Electrical resistivity (Ω·cm)(110-170)x10686x106

Manufacturing Methods
SmCo magnets are manufactured in the following forms:
Sintered - fine SmCo powder is compacted in a die and then sintered, fusing the powder into a solid material. There are two forms of pressing: die pressing (which involves a hard die into which the powder is placed and then pressed), and isostatic pressing (involving a special "rubber" die into which powder is placed and then pressed with equal force in all directions on the powder). Die pressed parts are smaller than isostatically pressed parts. Although the magnetic properties of isostatically pressed parts are higher, the uniformity of magnetic characteristics is usually lower than that of die pressed parts. Sintered parts usually need some finish machining in order to meet final tolerances.Compression Bonded - this is a technique whereby a special form of SmCo powder is blended with a plastic carrier material, die pressed and then heated. Parts made in this way can be of complex shapes and come off the tool with close tolerances, requiring no further finish machining. They have lower energy products than sintered materials - currently in the range of 15 MGOe.