Introduction to Alnico Magnets

Alnico magnets can be produced to simple or complex shapes and can be designed to be extremely powerful.

Alnico exists in Isotropic and Anisotropic versions (Isotropic can be magnetised in any direction; Anisotropic can only be magnetised in one pre-defined axis and has higher magnetic performance) and both can be produced by Casting and Sintering production methods. Cast Alnico 5 is historically the most popular grade but it has sub grades (Alnico 5 Anisotropic Cast Alnico 44, ACA44 is the common version). ACA44 is also known as LNG44, Alcomax 3 and Alnico 500. Alcomax 3 is often called Alnico 5 by other companies but it is actually ACA44 which is the correct grade type. Alnico5DG (ACA52) is also known as LNG52, Alcomax 3SC and Alnico600. Alnico5-7 (ACA60) is also known as LNG60, Columax and Alnico 700.

As is quickly apparent, many Alnico names have old trade names used and those trade names may have more than one grade to select from (e.g. Alcomax 3 is often called Alnico 5 but there are 4 versions of Alnico 5 in use today). To try to put clarity into Alnico naming we have used a letters plus numbers naming sequence together. We use ACA for Anisotropic Cast Alnico, ASA for Anisotropic Sintered Alnico, ICA for Isotropic Cast Alnico, ISA for Isotropic Sintered Alnico and BA for bonded Alnico (Alnico in a plastic binder – low performance isotropic properties). The numbers after these letters represent the BHmax Energy Product in kJ/m^3 (SI units). And three grades have ACAT (Alnico9 range) – these contain Titanium but are part of the ACA range. The whole Alnico range is below:-

Alnico 5 (Alnico5_ACA34) – Br=11.0kG, Hc=0.63kOe, Hci=0.65kOe, BHmax=4.25MGOe.
Alnico 5 (Alnico5_ACA37) – Br=11.8kG, Hc=0.61kOe, Hci=0.64kOe, BHmax=4.63MGOe.
Alnico 5 (Alnico5_ACA40) – Br=12.0kG, Hc=0.63kOe, Hci=0.65kOe, BHmax=5.00MGOe.
Alnico 5 (Alnico5_ACA44) – Br=12.5kG, Hc=0.65kOe, Hci=0.68kOe, BHmax=5.50MGOe.
Alnico 6 (Alnico6_ACA28) – Br=11.5kG, Hc=0.73kOe, Hci=0.75kOe, BHmax=3.50MGOe.
Alnico 5DG (Alnico5DG_ACA52) – Br=13.0kG, Hc=0.70kOe, Hci=0.73kOe, BHmax=6.50MGOe.
Alnico 5-7 (Alnico5-7_ACA60) – Br=13.5kG, Hc=0.73kOe, Hci=0.75kOe, BHmax=7.50MGOe.
Alnico 8 (Alnico8_ACA38) – Br=8.0kG, Hc=1.38kOe, Hci=1.4kOe, BHmax=4.75MGOe.
Alnico 8 (Alnico8_ACA40) – Br=8.5kG, Hc=1.44kOe, Hci=1.46kOe, BHmax=5.00MGOe.
Alnico 8 (Alnico8_ACA44) – Br=9.0kG, Hc=1.44kOe, Hci=1.46kOe, BHmax=5.50MGOe.
Alnico 8HC (Alnico8HC_ACA36) – Br=7.2kG, Hc=1.18kOe, Hci=1.90kOe, BHmax=4.50MGOe.
Alnico 9 (Alnico9_ACAT60) – Br=10.0kG, Hc=1.38kOe, Hci=1.4kOe, BHmax=7.50MGOe.
Alnico 9 (Alnico9_ACAT72) – Br=10.5kG, Hc=1.44kOe, Hci=1.46kOe, BHmax=9.00MGOe.
Alnico 9 (Alnico9_ACAT80) – Br=10.8kG, Hc=1.50kOe, Hci=1.53kOe, BHmax=10.00MGOe.

Alnico 5 (Alnico5_ASA34) – Br=11.5kG, Hc=0.60kOe, Hci=0.63kOe, BHmax=4.25MGOe.
Alnico 6 (Alnico6_ASA28) – Br=11.0kG, Hc=0.73kOe, Hci=0.75kOe, BHmax=3.50MGOe.
Alnico 8HC (Alnico8HC_ASA36) – Br=7.2kG, Hc=1.88kOe, Hci=1.90kOe, BHmax=4.50MGOe.
Alnico 8 (Alnico8_ASA38) – Br=8.0kG, Hc=1.38kOe, Hci=1.40kOe, BHmax=4.75MGOe.
Alnico 8 (Alnico8_ASA44) – Br=8.5kG, Hc=1.50kOe, Hci=1.53kOe, BHmax=5.50MGOe.
Alnico 8 (Alnico8_ASA48) – Br=9.2kG, Hc=1.56kOe, Hci=1.59kOe, BHmax=5.50MGOe.

Alnico 3 (Alnico3_ICA10) – Br=6.5kG, Hc=0.48kOe, Hci=0.50kOe, BHmax=1.25MGOe.
Alnico 2 (Alnico2_ICA12) – Br=7.5kG, Hc=0.56kOe, Hci=0.58kOe, BHmax=1.50MGOe.
Alnico 8 (Alnico8_ICA18) – Br=5.5kG, Hc=1.21kOe, Hci=1.21kOe, BHmax=2.25MGOe.

Alnico 3 (Alnico3_ISA10) – Br=6.5kG, Hc=0.50kOe, Hci=0.53kOe, BHmax=1.25MGOe.
Alnico 2 (Alnico2_ISA12) – Br=7.5kG, Hc=0.56kOe, Hci=0.58kOe, BHmax=1.50MGOe.
Alnico 8 (Alnico8_ISA18) – Br=6.0kG, Hc=1.19kOe, Hci=1.23kOe, BHmax=2.25MGOe.
Alnico 8 (Alnico8_ISA20) – Br=6.2kG, Hc=1.25kOe, Hci=1.31kOe, BHmax=2.50MGOe.

Alnico_BA7 – Br=3.1kG, Hc=1.00kOe, Hci=0.85kOe, BHmax=0.86MGOe.
Alnico_BA8 – Br=3.4kG, Hc=1.05kOe, Hci=1.00kOe, BHmax=1.00MGOe.

We specialize in producing magnets to customer requirements. Our production facility in China means we have very low costs for magnet production and can offer very competitive prices for customer requirements for Alnico. Please contact us for a quotation.

Alnico magnets have very high Br values, comparable with the NdFeB and SmCo magnets. They have an advantage in that they can be cast into complex shapes and can be given magnetised during the production heat treatment stages to give Alnico its final magnetic properties. The magnets are often magnetised in the final assembly to give the best performance (where magnetising is possible). This allows more complex magnetising patterns such as the Horseshoe magnet shape to be possible. Alnico shapes can be extremely complicated and include arcs, discs, rings, horseshoes, blocks, gears, trapezoids, cones, and many other customer-specific shapes.

Alnico 5-7 (Alnico5-7_ACA60) is the most powerful grade of Alnico. When put into the correct designs, this grade of Alnico will match NdFeB magnets for magnetic performance at room temperature but can continue to provide strong performance at temperatures over to and over +500 degree C.

Alnico 5 (Alnico5_ACA44) is one of the most popular grades of Alnico and is used instead of Alcomax 3.

As the magnets are sintered or cast, small production runs are generally not possible or, if done, may contain significant tooling charges and minimum quantity requests. It may be possible to machine smaller magnets from larger parts although this will have cost implications as well.