Metallurgy/carbon steel magnetism
I have a question that I have been asking online for weeks only to get conflicting answers and or complicated magnetism and physics lessons. I have a project that requires that I shape a piece of carbon steel and then permanently magnetize it. Machining the piece, heating and magnetizing I've got covered.The material I need to use is carbon steel.I know there are better materials that can be used to make a strong permanent magnet like neodymium, boron, silicon etc, but my project calls for iron carbon alloy ONLY. My question simply is- What percentage of carbon in the steel would make the strongest permanent magnet? And with that- What specific grade of carbon steel do I need to purchase. If you could help me with this question, it would be so much appreciated. If this isn't your expertise them maybe you can direct me to some who can give me a straight answer. Thank you
ANSWER: Dear Mathew,
How can you get straight answer as you know straightly what are you searching, not me or anyone else.Following guidelines will surely help you in selecting one of the best option suiting your taste.All the best.
Neodymium magnets are by far the strongest type of permanent magnet available. It depends on the application. If you need the highest strength in the smallest possible package at room temperature, grade N52 is the strongest available.
Many of our magnets are offered in grade N42, which is a great balance between cost, strength and performance at higher operating temperatures. You can get the same strength as an N52 magnet by using a slightly larger N42 magnet.
If you have slightly elevated temperatures, in the 140°F to 176°F range (60°C -80°C), N42 magnets might actually be stronger than N52.
Neodymium Magnet Physical Properties
Magnet Summary Table - Click this link for the pull force and surface field of each of our stock magnets listed in table format
Material Type Residual Flux Density
(Br) Coercive Force
(Hc) Intrinsic Coercive Force (Hci) Max.Energy Product
N35 11.7-12.1 KGs >11.0 KOe >12 KOe 33-35 MGOe
N38 12.2-12.6 KGs >11.0 KOe >12 KOe 36-38 MGOe
N40 12.6-12.9 KGs >11.0 KOe >12 KOe 38-40 MGOe
N42 13.0-13.2 KGs >11.0 KOe >12 KOe 40-42 MGOe
N45 13.3-13.7 KGs >11.0 KOe >12 KOe 43-45 MGOe
N48 13.8-14.2 KGs >11.0 KOe >12 KOe 45-48 MGOe
N50 14.1-14.5 KGs >11.0 KOe >11 KOe 48-50 MGOe
N52 14.5-14.8 KGs >11.2 KOe >11 KOe 49.5-52 MGOe
N35M 11.7-12.1 KGs >11.4 KOe >14 KOe 33-35 MGOe
N38M 12.2-12.6 KGs >11.4 KOe >14 KOe 36-38 MGOe
N40M 12.6-12.9 KGs >11.4 KOe >14 KOe 38-40 MGOe
N42M 13.0-13.3 KGs >11.4 KOe >14 KOe 40-42 MGOe
N45M 13.3-13.7 KGs >11.4 KOe >14 KOe 42-45 MGOe
N48M 13.6-14.2 KGs >11.4 KOe >14 KOe 45-48 MGOe
N50M 14.1-14.5 KGs >11.4 KOe >14 KOe 48-50 MGOe
N33H 11.4-11.7 KGs >10.3 KOe >17 KOe 31-33 MGOe
N35H 11.7-12.1 KGs >10.8 KOe >17 KOe 33-35 MGOe
N38H 12.2-12.6 KGs >11.4 KOe >17 KOe 36-38 MGOe
N40H 12.6-12.9 KGs >11.4 KOe >17 KOe 38-40 MGOe
N42H 13.0-13.3 KGs >11.4 KOe >17 KOe 40-42 MGOe
N45H 13.3-13.7 KGs >11.4 KOe >17 KOe 42-45 MGOe
N48H 13.6-14.2 KGs >11.4 KOe >16 KOe 45-48 MGOe
N30SH 10.8-11.2 KGs >10.1 KOe >20 KOe 28-30 MGOe
N33SH 11.4-11.7 KGs >10.3 KOe >20 KOe 31-33 MGOe
N35SH 11.7-12.1 KGs >10.8 KOe >20 KOe 33-35 MGOe
N38SH 12.2-12.6 KGs >11.4 KOe >20 KOe 36-38 MGOe
N40SH 12.6-12.9 KGs >11.4 KOe >20 KOe 38-40 MGOe
N42SH 13.0-13.3 KGs >11.4 KOe >20 KOe 40-42 MGOe
N45SH 13.3-13.7 KGs >11.4 KOe >19 KOe 43-45 MGOe
N28UH 10.4-10.8 KGs >9.8 KOe >25 KOe 26-28 MGOe
N30UH 10.8-11.2 KGs >10.1 KOe >25 KOe 28-30 MGOe
N33UH 11.4-11.7 KGs >10.3 KOe >25 KOe 31-33 MGOe
N35UH 11.7-12.1 KGs >10.8 KOe >25 KOe 33-35 MGOe
N38UH 12.2-12.6 KGs >11.4 KOe >25 KOe 36-38 MGOe
N40UH 12.6-12.9 KGs >11.4 KOe >25 KOe 38-40 MGOe
N30EH 10.8-11.2 KGs >10.1 KOe >30 KOe 28-30 MGOe
N33EH 11.4-11.7 KGs >10.3 KOe >30 KOe 31-33 MGOe
N35EH 11.7-12.1 KGs >10.8 KOe >30 KOe 33-35 MGOe
N38EH 12.2-12.6 KGs >10.8 KOe >30 KOe 36-38 MGOe
Neodymium Material Type Maximum Operating Temp Curie Temp
°C (°F) °C (°F)
N 176°F (80°C) 590°F (310°C)
NM 212°F (100°C) 644°F (340°C)
NH 248°F (120°C) 644°F (340°C)
NSH 302°F (150°C) 644°F (340°C)
NUH 356°F (180°C) 662°F (350°C)
NEH 392°F (200°C) 662°F (350°C)
The Thermal Characteristics listed above are values commonly associated with each magnet'sgrade or material. Actual performance in your application may vary with other factors, including the shape of the magnet, the Permeance Coefficient or load line, and how it is used in a circuit. See our in-depth article on Temperature and Neodymium Magnets for more details.
Physical and Mechanical Characteristics
Density 7.4-7.5 g/cm3
Compression Strength 950 MPa (137,800 psi)
Tensile Strength 80 MPa (11,600 psi)
Vickers Hardness (Hv) 560-600
Young's Modulus 160 GPa (23,200 psi)
Recoil Permeability 1.05 μrec
Electrical Resistance (R) 160 μ-ohm-cm
Heat Capacity 350-500 J/(kg.°C)
Thermal Expansion Coefficient (0 to 100°C)
parallel to magnetization direction 5.2 x 10-6 /°C
Thermal Expansion Coefficient (0 to 100°C)
perpendicular to magnetization direction -0.8 x 10-6 /°C
Plating Type Overall Thickness Salt Spray Test Pressure Cooker Test
NiCuNi (Nickel Copper 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 plating layers are 1-2 μm thick.
Test results shown to allow comparison between plating 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.
SELECT MATERIAL AS PER YOUR SPECS/STANDARD.
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QUESTION: I don't understand what is wrong with my question. I need to make a magnet out of carbon steel. Steel which only has iron and carbon. What percentage of carbon does the steel need to make a strong permanent magnet. If I have pure iron and want to make it into a permanent magnet how much carbon do I need to add.
Surely, there is a serious problem with your question- you want to make permanent magnet from plane carbon steel (iron+carbon) without understanding the basic requirement of permanent magnetic steel.
Neodymium-Boron-Iron makes a grade for your target alloy.These are popular as NIB steels.
Still if you want to know carbon contents, answer is 0.003%.
You can't make strong permanent magnet from iron+carbon alloy(plain carbon steel).
Trust your query remains plugged, all the best for making "impossible" a "possible" as the word "Impossible says---I M POSSIBLE"