Permanent magnets and electromagnets
Alnico Magnets
Alnico magnets are composed of aluminum, nickel, cobalt and iron.They are manufactured using a process of either casting or sintering to create various shapes, and they are also very resistant to high temperatures.
Magnetic properties:
| Grade | Br | Hc | (BH) max | Tc | A Br | MMPA Equivalent | |||
| [mT] | [Gs] | [Ka/m] | [Oe] | [KJ/m3] | [MGOe] | [℃] | [℃] | ||
| LN10 | 650 | 6500 | 42 | 530 | 10.0 | 1.20 | 810 | - 0,03 | Alnico 3 |
| LNG 11 | 720 | 7200 | 37 | 480 | 11.2 | 1.40 | 810 | - 0,03 | Alnico 1 |
| LNG 13 | 700 | 7000 | 50 | 620 | 13.0 | 1.60 | 810 | - 0,03 | Alnico 2 |
| LNGT 18 | 580 | 5800 | 90 | 1130 | 18.0 | 2.20 | 860 | - 0,03 | [I Alnico 8 ] |
| LNG 16 | 800 | 8000 | 53 | 660 | 16.0 | 2.00 | 850 | - 0,03 | Alnico 4 |
| LNG 34 | 1180 | 11800 | 44 | 550 | 35.0 | 4.30 | 860 | - 0,02 | [Alnico 5C] |
| LNG 37 | 1180 | 11800 | 48 | 600 | 37.0 | 4.65 | 860 | - 0,02 | [Alnico 5C] |
| LNG 40 | 1220 | 12200 | 48 | 600 | 40.0 | 5.00 | 860 | - 0,02 | Alnico 5C |
| LNG 44 | 1220 | 12200 | 52 | 650 | 44.0 | 5.50 | 860 | - 0,02 | Alnico 5C |
| LNG 52 | 1250 | 12500 | 55 | 690 | 52.0 | 6.50 | 860 | - 0,02 | Alnico 5DG |
| LNG 60 | 1300 | 13000 | 56 | 700 | 60.0 | 7.50 | 860 | - 0,02 | Alnico 5-7 |
| LNGT 28 | 1050 | 10500 | 56 | 700 | 28.0 | 3.50 | 860 | - 0,02 | Alnico 6 |
| LNGT 32 | 800 | 8000 | 104 | 1300 | 34.0 | 4.25 | 860 | - 0,03 | Alnico 8 |
| LNGT 38 | 820 | 8200 | 110 | 1380 | 38.0 | 4.75 | 860 | - 0,03 | Alnico 8 |
| LNGT 44 | 880 | 8800 | 120 | 1500 | 44.0 | 5.50 | 860 | - 0,03 | Alnico 8 |
| LNGT 60 | 900 | 9000 | 110 | 1380 | 60.0 | 7.50 | 860 | - 0,03 | Alnico 8 |
| LNGT 72 | 1050 | 10500 | 112 | 1420 | 72.0 | 9.00 | 860 | - 0,03 | Alnico 9 |
| LNGT 36J | 700 | 7000 | 140 | 1750 | 36.0 | 4,50 | 860 | - 0,03 | Alnico 8HC |
General casting tolerances of Alnico::
| US Inches/pollici | METRIC - Millimeters | ||||
| Range | Standard | Optimistic | Range | Standard | Optimistic |
| Up to 1/2" | +/-0.007 | +/-0.003 | Up to 12.7 mm | +/-0.18 | +/-0.08 |
| 1/2" - 1" | +/-0.010 | +/-0.005 | 12.7 - 25.4 mm | +/-0.25 | +/-0.13 |
| 1" - 2" | +/-0.015 | +/-0.010 | 25.4 - 50.8 mm | +/-0.38 | +/-0.25 |
| 2" - 3" | +/-0.020 | +/-0.015 | 50.8 - 72.6 mm | +/-0.51 | +/-0.38 |
| 3" - 4" | +/-0.025 | +/-0.018 | 72.6 - 101.6 mm | +/-0.64 | +/-0.46 |
| 4" - 5" | +/-0.030 | +/-0.020 | 101.6 - 127.0 mm | +/-0.76 | +/-0.51 |
| 5" - 6" | +/-0.032 | +/-0.022 | 127.0 - 152.4 mm | +/-0.81 | +/-0.56 |
| 6" - 7" | +/-0.035 | +/-0.035 | 152.4 - 177.8 mm | +/-0.89 | +/-0.64 |
| 7" - 8" | +/-0.038 | +/-0.038 | 177.8 - 203.2 mm | +/-0.96 | +/-0.71 |
Flatness: referring to a single flat surface:
| US Inches/pollici | METRIC - Millimeters | ||
| Thickness | Dish per 6 sq. inches | Thickness of surface | Dish per 42 sq. inches of surface |
| up to 0.250" | Insignificant | up to 6.5mm | Insignificant |
| 0.251"-0.500" | 0.004" TIR | 6.5mm - 13mm | 0.102mm TIR |
| 0.500"-1.000 | 0.008" TIR | 6.5mm - 13mm | 0.102mm TIR |
| 0.501"-1.000" | 0.008" TIR | 6.5mm - 13mm | 0.102mm TIR |
Straightness: the as-cast linear tolerance on an axial piece: +/-0.005 " per pollice (:toll.+/-0.127mm : per 25mm).
Angularity: the as-cast angle tolerance lies between +/- 1° ~ +/-2°
Raw material thickness: the standard minimum part thickness is 0.02" (0.5mm)
Roundness of raw material: diametrical variations in solid round sections can be seen in the table below:
| US Inches/pollici | METRIC - Millimeters | ||
| Tolerances | Diameter | Tolerances | Diameter |
| up to 1" | 0.006" TIR | up to 25mm | 0.125mm TIR |
| 1" - 1.5" | 0.008" TIR | 25mm - 37.5mm | 0.203mm TIR |
| 1.5" - 2" | 0.010" TIR | 37.5mm - 50mm | 0.254mm TIR |
| 2" - 3" | 0.015" TIR | 50mm - 75mm | 0.381mm TIR |