A Brief Introduction To Neodymium Magnets (NdFeB)

NdFeB magnet is a kind of rare earth permanent magnet. In fact, this kind of magnet should be called rare earth iron boron magnet, because this kind of magnet uses more rare earth elements than just neodymium. But it is easier for people to accept the name NdFeB, it is easy to understand and spread. There are three kinds of rare earth permanent magnets, divided into three structures RECo5, RE2Co17, and REFeB. NdFeB magnet is the REFeB, the RE are the rare earth elements.

Sintered NdFeB permanent magnet material is based on the intermetallic compound Nd2Fe14B, the main components are neodymium, iron, and boron. In order to get different magnetic properties, a part of neodymium can be replaced by other rare earth metals such as dysprosium and praseodymium, and a part of iron can be replaced by other metals such as cobalt and aluminum. The compound has a tetragonal crystal structure, with high saturation magnetization strength and uniaxial anisotropy field, which is the main source of the properties of NdFeB permanent magnets.

Sintered NdFeB permanent magnet materials are classified into different classes according to Intrinsic Coercivity. Low coercivity N grade, medium coercivity M grade, high coercivity H grade, very high coercivity SH grade, and then UH, EH, and TH grade, especially the new AH grade that the intrinsic coercivity can be over 35 kA/m.

The maximum operating temperature of different grades of NdFeB magnetic materials is also related to intrinsic coercivity. Different grades of NdFeB have different working temperatures, the higher the intrinsic coercivity, the higher the maximum operating temperature.

There is a test standard for the maximum operating temperature, usually using the material grade, cylindrical sample bar, diameter D and height L, L/D=0.7, after saturation magnetized, heated from room temperature to a constant temperature and hold for 2 hours, then cooled to room temperature, open circuit flux irreversible flux loss ≤ 5%.

As the NdFeB application field requires a higher and higher working temperature of NdFeB, the whole NdFeB industry is constantly updating its technology, and at the same time, the strongest magnetic performance per unit volume of NdFeB is becoming more and more obvious. This has led to the replacement of other magnetic materials in many applications. For example, the magnetic material in the ignition coil of an automobile engine requires a working temperature above 200˚C. With the maturity of the technology, N35EH can meet the requirements of the industry in terms of cost and performance.

ndfeb-structure

NdFeB Magnet Development Trends

Sintered NdFeB magnets have been widely used in many fields such as the computer industry, automotive industry, medical equipment, energy transportation, etc. In addition, NdFeB magnets have been widely used in many new fields, especially in the low-carbon economy. Especially, under the trend of a low carbon economy sweeping the world, all countries in the world are paying attention to environmental protection and low carbon emission as the key science and technology field. This has put forward new requirements for improving energy structure, developing renewable energy, improving efficiency, energy saving and emission reduction, and advocating low-carbon life, which also provides a broad market space for the development of low-carbon economy industries such as wind power generation, new energy vehicles, and energy-saving home appliances. As the application becomes more and more widespread and the technology continues to develop, the sintered NdFeB used will have higher requirements. For example, the voice coil motor (VCM) of the mechanical hard disk for data storage requires N50H sintered NdFeB magnets with maximum magnetic energy product (BH) max> 48MGOe and Intrinsic Coercivity Hcj> 16kOe; while the ignition coil of automobile engine uses high performance sintered NdFeB magnets in the shape of thin sheet, which requires working temperature above 200 °C, which requires N35EH sintered NdFeB magnets to be used. In many emerging applications of sintered NdFeB magnets, such as the recent mechanical-minded walking robots, special motors with integrated technology, automotive automatic systems, etc., both high BH max and high Intrinsic Coercivity are required. The demand for high magnetic energy product (BH) max and high Intrinsic Coercivity is also high. Rare earth is an important strategic resource, and improving the comprehensive magnetic properties of sintered NdFeB magnets is beneficial to the efficient use of rare earth. Therefore, the trend of sintered Nd-Fe-B magnets is to increase the maximum magnetic energy product (BH)max and the Intrinsic Coercivity Hcj.

Coating Thickness(μm) Color SST(hrs) PCT(hrs)
BW-Zn 4-15 Bright blue ≥24 –
Color-Zn 4-15 Shining color ≥48 –
Ni-Cu-Ni 5-20 Bright silver ≥48 ≥48
Electroless Ni 5-20 Dark silver ≥72 ≥48
Ni-Cu-Ni-Au 5-20 Golden ≥72 ≥96
Ni-Cu-Ni-Ag 5-20 Silver ≥72 ≥96
Ni-Cu-Ni-Sn 5-20 Silver ≥72 ≥96
Phosphate 1-3 Dark grey – –
Aluminum 2-15 Bright silver ≥24 ≥24
Epoxy resin 10-30 Black/Grey ≥72 ≥72
Parylene 5-20 Colorless ≥96 –
Everlube 10-15 Golden yellow ≥120 ≥72
Teflon 8-15 Black ≥24 ≥24
Note: anti-corrosion capability of coating is also influenced by the shape and size of magnet.

NdFeB Magnet Coating and Plating

Sintered NdFeB has the strongest magnetic properties, but it has one of its biggest weaknesses, its corrosion resistance is too poor, so sintered NdFeB needs to be plated.

NdFeB plating process usually includes oil removal, water washing, ultrasonic pickling, ultrasonic water washing, soaking in MJ670 passivation solution, then many times water washing, then nickel or zinc t plating, etc. Among them, passivation sealing treatment is an important role in NdFeB plating. Because the production process of sintered NdFeB is a powder metallurgy process, there will be small pores on the surface of the product. To make the plating layer more dense and improve the corrosion resistance, the passivation sealing treatment before plating is very important.

Manufacturing Process

Step 1， Raw Material Preparation and pretreatment

The production of NdFeB magnets requires different materials according to the composition, including neodymium metal, praseodymium, special boron, fine boron, copper, aluminum, gallium, terbium, cobalt, iron, dysprosium, niobium, etc. Material oxidation has a significant impact on magnetic performance, so materials that are prone to oxidation need to be descaled and weighed according to the material recipe.
The machines used are electronic scales, cutting machines, descaling and polishing machines, etc.
In the production control program, the main control points are the weighing of the material, the proportioning of the material, and the surface cleaning of the material.

Step 2， Strip Casting

Originally, vacuum melting furnaces are used in China to melt the material prepared in the previous step. It is usually used to produce NdFeB magnets with low-performance requirements. As the performance of NdFeB is more and more demanding, it is necessary to increase the volume percentage of Nd2Fe14B in the main phase, improve the grain orientation, and keep about 2% of neodymium-rich phase to ensure the coercivity, so it is necessary to prevent or minimize the formation of α-Fe during the casting process, using the method of strip casting, so that the γ-Fe is not nucleated in time (α-Fe is the transformation of γ-Fe at low temperature). The main phase of Nd2Fe14B is generated directly to suppress the precipitation of α-Fe.

Step 3， Hydrogen crushing

After melting, the small sheet of material will be placed in the environment of hydrogen and using the hydrogen absorption property among rare earth metals, hydrogen enters the alloy along the thin layer of the neodymium-rich phase, causing it to expand and burst and break, and cracking along the neodymium-rich phase layer, thus turning the sheet material into a coarse powder. The coarse powder is mixed uniformly by the rotation of the stirring tank.

Step 4， Airflow Mill Grinding

The coarse powder in the previous process is blown up by high-pressure airflow, and the particle size becomes small through the collision between the coarse powder particles, which becomes the fine powder.

This process needs to prevent the powder from coming into contact with oxygen, so all containers need to exclude oxygen with nitrogen, etc. Bagging also needs to be filled with nitrogen. The fines are all tested for particle size to meet the process requirements. The different grades of fine powders are mixed with a mixer according to the composition ratio.

Step 5， Press Forming

Unlike the press forming process of sintered Alnico magnet, rare earth magnets, NdFeB, and SmCo need to be oriented during the press forming process, so the forming shape of rare earth magnets is simple square or cylinder. The design of the press machine also includes a magnetic field and demagnetization device. The mold has an upper cylinder and lower cylinder, when the powder is caved according to the weight requirement, the upper cylinder is pressed down, the electromagnetic field is oriented, continues to press down, holds pressure for a certain time, demagnetizes, at this time the upper cylinder is withdrawn and the lower cylinder pushes the molding product out.

In the press forming process, the density of the product is an important indicator, and the split is the weight and size of the forming product, so in this process, in addition to the first and last inspection need to test the weight and size of the forming product, the operator has a certain interval to inspect the product. Thus, to ensure the quality of the product in this process.

Step 6， Cold Isostatic Pressing

The cold isostatic pressing is the ultra-high pressure medium in the closed container, the liquid medium is usually oil, and the NdFeB formed Semi-finished block will be pressed in all directions equally, so that the density of the product increases, and the shrinkage depends on the compressibility of the material and the size of the pressure when pressing. After cold isostatic pressing, the density of NdFeB molding blanks increases, increasing the product’s density for the subsequent sintering process. The density of NdFeB has a great relationship with magnetic performance.

Step 7， Sintering Process

The sintering process is one of the most important processes of sintering NdFeB magnet, which is done in a vacuum sintering furnace. Unlike the sintering Alnico magnets, the sintering process of NdFeB also includes the process of heat treatment. The sintering furnace cavity will be vacuumed first, and after putting the products into the furnace cavity, it will be heated up to about 800˚C first, and then heated up and exhausted. This is because there are pores in the product and there will be a lot of gas inside the product. The vacuum level is 4.2E-2Pa. Then the product is sintered at a high temperature, about 1200˚C, for more than 4 hours. Then the heat treatment stage will take place. The product is first kept at about 900˚C for 2 hours and then held at 550˚C for 5 hours. Then cooling out of the furnace. There will be some differences in temperature control for different grades and materials, but this is roughly the process.

Step 8， Machining

The machine processing of sintered NdFeB magnet has developed a lot in recent years, for NdFeB small products, a multi-wire cutting machine has replaced the previous wire cutting, which makes the cutting of NdFeB magnet much more efficient. For sinkhole products, special diamond tools are used for processing. For general size use wire cutting. Because the use of NdFeB all over the world is increasing every year, let the equipment of this industry develop rapidly.

Step 8， Coating and Plating

The anti-corrosion ability of NdFeB is very poor because the Nd-rich phase in sintered NdFeB is prone to oxidation, which eventually leads to the powder frothing of sintered NdFeB products, so the sintered NdFeB needs to be plated or coated with anti-oxidation layer to prevent the products from direct contact with the atmosphere.

The commonly used plating layers for sintered NdFeB are Zn, Ni, and NiCuNi, etc., which need to be passivated and plated before plating.

Performance table of Sintered NdFeB magnets

GRADE remanence Coercive force intrinsic coercive force Maximum energy product HIGHEST WORKING TEMPERATURE DENSITY
Br Hcb Hcj (BH)max
T kGs kA/m kOe kA/m kOe kJ/m3 MGOe ℃ g/cm3
N30 1.08-1.13 10.8-11.3 ≥798 ≥10.0 ≥955 ≥12 223-247 28-31 80 ≥7.5
N33 1.13-1.17 11.3-11.7 ≥836 ≥10.5 ≥955 ≥12 247-271 31-34 80 ≥7.5
N35 1.17-1.22 11.7-12.2 ≥868 ≥10.9 ≥955 ≥12 263-287 33-36 80 ≥7.5
N38 1.22-1.25 12.2-12.5 ≥899 ≥11.3 ≥955 ≥12 287-310 36-39 80 ≥7.5
N40 1.25-1.28 12.5-12.8 ≥907 ≥11.4 ≥955 ≥12 302-326 38-41 80 ≥7.5
N42 1.28-1.32 12.8-13.2 ≥915 ≥11.5 ≥955 ≥12 318-342 40-43 80 ≥7.5
N45 1.32-1.38 13.2-13.8 ≥923 ≥11.6 ≥955 ≥12 342-366 43-46 80 ≥7.5
N48 1.38-1.42 13.8-14.2 ≥923 ≥11.6 ≥955 ≥12 366-390 46-49 80 ≥7.5
N50 1.40-1.45 14.0-14.5 ≥796 ≥10.0 ≥876 ≥11 382-406 48-51 80 ≥7.5
N52 1.43-1.48 14.3-14.8 ≥796 ≥10.0 ≥876 ≥11 398-422 50-53 80 ≥7.5
N55 1.46-1.52 14.6-15.2 ≥796 ≥10.0 ≥876 ≥11 414-430 52-54 80 ≥7.5
N35M 1.17-1.22 11.7-12.2 ≥868 ≥10.9 ≥1114 ≥14 263-287 33-36 100 ≥7.5
N38M 1.22-1.25 12.2-12.5 ≥899 ≥11.3 ≥1114 ≥14 287-310 36-39 100 ≥7.5
N40M 1.25-1.28 12.5-12.8 ≥923 ≥11.6 ≥1114 ≥14 302-326 38-41 100 ≥7.5
N42M 1.28-1.32 12.8-13.2 ≥955 ≥12.0 ≥1114 ≥14 318-342 40-43 100 ≥7.5
N45M 1.32-1.38 13.2-13.8 ≥995 ≥12.5 ≥1114 ≥14 342-366 43-46 100 ≥7.5
N48M 1.37-1.43 13.7-14.3 ≥1027 ≥12.9 ≥1114 ≥14 366-390 46-49 100 ≥7.5
N50M 1.40-1.45 14.0-14.5 ≥1033 ≥13.0 ≥1114 ≥14 382-406 48-51 100 ≥7.5
N52M 1.43-1.48 14.3-14.8 ≥1050 ≥13.2 ≥1114 ≥14 398-422 50-53 100 ≥7.5
N54M 1.45-1.50 14.5-15.0 ≥1051 ≥13.2 ≥1114 ≥14 414-438 52-55 100 ≥7.5
N35H 1.17-1.22 11.7-12.2 ≥868 ≥10.9 ≥1353 ≥17 263-287 33-36 120 ≥7.5
N38H 1.22-1.25 12.2-12.5 ≥899 ≥11.3 ≥1353 ≥17 287-310 36-39 120 ≥7.5
N40H 1.25-1.28 12.5-12.8 ≥923 ≥11.6 ≥1353 ≥17 302-326 38-41 120 ≥7.5
N42H 1.28-1.32 12.8-13.2 ≥955 ≥12.0 ≥1353 ≥17 318-342 40-43 120 ≥7.5
N45H 1.32-1.36 13.2-13.6 ≥963 ≥12.1 ≥1353 ≥17 342-366 43-46 120 ≥7.5
N48H 1.37-1.43 13.7-14.3 ≥995 ≥12.5 ≥1353 ≥17 366-390 46-49 120 ≥7.5
N50H 1.40-1.45 14.0-14.5 ≥1011 ≥12.7 ≥1353 ≥17 382-406 48-51 120 ≥7.5
N52H 1.43-1.48 14.3-14.8 ≥1027 ≥12.9 ≥1353 ≥17 398-422 50-53 120 ≥7.5
N33SH 1.14-1.18 11.4-11.8 ≥852 ≥10.7 ≥1592 ≥20 247-279 31-35 150 ≥7.5
N35SH 1.17-1.22 11.7-12.2 ≥876 ≥11.0 ≥1592 ≥20 263-287 33-36 150 ≥7.5
N38SH 1.22-1.25 12.2-12.5 ≥907 ≥11.4 ≥1592 ≥20 287-310 36-39 150 ≥7.5
N40SH 1.25-1.28 12.5-12.8 ≥939 ≥11.8 ≥1592 ≥20 302-326 38-41 150 ≥7.5
N42SH 1.28-1.32 12.8-13.2 ≥987 ≥12.4 ≥1592 ≥20 318-342 40-43 150 ≥7.5
N45SH 1.32-1.38 13.2-13.8 ≥1003 ≥12.6 ≥1592 ≥20 342-366 43-46 150 ≥7.5
N48SH 1.37-1.43 13.7-14.3 ≥1027 ≥12.9 ≥1592 ≥20 366-390 46-49 150 ≥7.5
N50SH 1.40-1.45 14.0-14.5 ≥1003 ≥12.6 ≥1592 ≥20 382-406 48-51 150 ≥7.5
N28UH 1.04-1.08 10.4-10.8 ≥764 ≥9.6 ≥1990 ≥25 207-231 26-29 180 ≥7.5
N30UH 1.08-1.13 10.8-11.3 ≥812 ≥10.2 ≥1990 ≥25 223-247 28-31 180 ≥7.5
N33UH 1.13-1.17 11.3-11.7 ≥852 ≥10.7 ≥1990 ≥25 247-271 31-34 180 ≥7.5
N35UH 1.17-1.22 11.7-12.2 ≥860 ≥10.8 ≥1990 ≥25 263-287 33-36 180 ≥7.5
N38UH 1.22-1.25 12.2-12.5 ≥876 ≥11.0 ≥1990 ≥25 287-310 36-39 180 ≥7.5
N40UH 1.25-1.28 12.5-12.8 ≥899 ≥11.3 ≥1990 ≥25 302-326 38-41 180 ≥7.5
N42UH 1.28-1.32 12.8-13.2 ≥899 ≥11.3 ≥1990 ≥25 318-342 40-43 180 ≥7.5
N45UH 1.32-1.36 13.2-13.6 ≥908 ≥11.4 ≥1990 ≥25 342-366 43-46 180 ≥7.5
N48UH 1.37-1.43 13.7-14.3 ≥908 ≥11.4 ≥1990 ≥25 366-390 46-49 180 ≥7.5
N28EH 1.04-1.08 10.4-10.8 ≥780 ≥9.8 ≥2388 ≥30 207-231 26-29 200 ≥7.5
N30EH 1.08-1.13 10.8-11.3 ≥812 ≥10.2 ≥2388 ≥30 223-247 28-31 200 ≥7.5
N33EH 1.13-1.17 11.3-11.7 ≥836 ≥10.5 ≥2388 ≥30 247-271 31-34 200 ≥7.5
N35EH 1.17-1.22 11.7-12.2 ≥876 ≥11.0 ≥2388 ≥30 263-287 33-36 200 ≥7.5
N38EH 1.22-1.25 12.2-12.5 ≥899 ≥11.3 ≥2388 ≥30 287-310 36-39 200 ≥7.5
N40EH 1.25-1.28 12.5-12.8 ≥899 ≥11.3 ≥2388 ≥30 302-326 38-41 200 ≥7.5
N42EH 1.28-1.32 12.8-13.2 ≥899 ≥11.3 ≥2388 ≥30 318-342 40-43 200 ≥7.5
N45EH 1.32-1.36 13.2-13.6 ≥899 ≥11.3 ≥2388 ≥30 342-366 43-46 200 ≥7.5
N28AH 1.04-1.08 10.4-10.8 ≥787 ≥9.9 ≥2786 ≥35 207-231 26-29 230 ≥7.5
N30AH 1.08-1.13 10.8-11.3 ≥819 ≥10.3 ≥2786 ≥35 223-247 28-31 230 ≥7.5
N33AH 1.13-1.17 11.3-11.7 ≥843 ≥10.6 ≥2786 ≥35 247-271 31-34 230 ≥7.5
N35AH 1.17-1.22 11.7-12.2 ≥876 ≥11.0 ≥2786 ≥35 263-287 33-36 230 ≥7.5
N38AH 1.22-1.25 12.2-12.5 ≥899 ≥11.3 ≥2786 ≥35 287-310 36-39 230 ≥7.5
N40AH 1.26-1.31 12.6-13.1 ≥939 ≥11.8 ≥2786 ≥35 302-334 38-42 230 ≥7.5
N42AH 1.29-1.35 12.9-13.5 ≥955 ≥12.0 ≥2786 ≥35 318-350 40-44 230 ≥7.5
G48SH 1.37-1.42 13.7-14.2 >1011 >13 >1592 >20 358-390 45-49 <150 >7.5
G50SH 1.40-1.45 14.0-14.5 >1027 >13.2 >1592 >20 374-406 47-51 <150 >7.5
G52SH 1.42-1.48 14.2-14.8 >1067 >13.4 >1592 >20 390-422 49-53 <150 >7.5
G55SH 1.46-1.51 14.6-15.1 >1083 >13.6 >1592 >20 406-438 51-55 <150 >7.5
G45UH 1.33-1.38 13.3-13.8 >978 >12.4 >1990 >25 334-366 42-46 <180 >7.5
G48UH 1.37-1.42 13.7-14.2 >1027 >12.9 >1990 >25 358-390 45-49 <180 >7.5
G50UH 1.40-1.45 14.0-14.5 >1051 >13.2 >1990 >25 374-406 47-51 <180 >7.5
G52UH 1.42-1.48 14.2-14.8 >1067 >13.5 >1990 >25 390-422 49-53 <180 >7.5
G54UH 1.46-1.51 14.6-15.1 >1075 >13.5 >1990 >25 406-438 51-55 <180 >7.5
G40EH 1.26-1.31 12.6-13.1 >955 >12.0 >2388 >30 302-334 38-42 <200 >7.5
G44EH 1.29-1.35 12.6-13.1 >971 >12.2 >2388 >30 318-350 40-44 <200 >7.5
G46EH 1.33-1.38 12.6-13.1 >1011 >12.7 >2388 >30 334-366 42-46 <200 >7.5
G48EH 1.37-1.42 12.6-13.1 >1027 >12.9 >2388 >30 358-390 45-49 <200 >7.5
G50EH 1.40-1.45 12.6-13.1 >1051 >13.2 >2388 >30 374-406 47-51 <200 >7.5

Grain Boundary Diffusion (GBD) NdFeB Magnet

The key element of NdFeB with high coercivity, Dy, Tb, has a high anisotropic field HA. After adding it to replace Nd, it plays a major role in improving coercivity, while other elements such as Ga, Al, Cu, Zr, and Co play a minor role. With the increase of Dy and Tb, the coercivity increases, so the series of grades such as M, H, SH, UH, EH, etc. However, with the increase of Dy, Tb, the remanent magnetization of magnets monotonically decreases, and a contradictory extreme phenomenon is formed for quite a long time.

“The Alloying Process by Grain Boundary Diffusion” is a new technology developed by Shin-Etsu Chemical, in which the dysprosium is concentrated near the grain boundaries of the Nd-Fe-B sintered magnet. With this new process, further enhancement in coercivity and suppression of reduction in remanence, compared with the conventional “Two Alloy method”, has been realized.

The sintered small thin sintered NdFeB is coated with a compound of Dy, and a diffusion heat treatment is performed at a temperature lower than the sintering temperature, and Dy forms a sharp concentration distributed in the thin layer at the grain boundaries during the grain boundary diffusion reaction. With this process, Dy greatly increases the magnet coercivity Hcj without decreasing Br or slightly decreasing it, so that high remanence and high coercivity can be achieved.

the grain boundary diffusion is suitable for diffusion processes: 1.5 mm ≤ thickness ≤ 8 mm.

For magnets thicker than 4 mm, the center layer Hcj is lower than the standard value, in the range of

about 1.5KOe.

Magnetic Properties OF NdFeB Magnet (GBD)

GRADE remanence Coercive force intrinsic coercive force Maximum energy product HIGHEST WORKING TEMPERATURE DENSITY
Br Hcb Hcj (BH)max
T kGs kA/m kOe kA/m kOe kJ/m3 MGOe ℃ g/cm3
G48SH 1.37-1.42 13.7-14.2 >1011 >13 >1592 >20 358-390 45-49 <150 >7.5
G50SH 1.40-1.45 14.0-14.5 >1027 >13.2 >1592 >20 374-406 47-51 <150 >7.5
G52SH 1.42-1.48 14.2-14.8 >1067 >13.4 >1592 >20 390-422 49-53 <150 >7.5
G55SH 1.46-1.51 14.6-15.1 >1083 >13.6 >1592 >20 406-438 51-55 <150 >7.5
G45UH 1.33-1.38 13.3-13.8 >978 >12.4 >1990 >25 334-366 42-46 <180 >7.5
G48UH 1.37-1.42 13.7-14.2 >1027 >12.9 >1990 >25 358-390 45-49 <180 >7.5
G50UH 1.40-1.45 14.0-14.5 >1051 >13.2 >1990 >25 374-406 47-51 <180 >7.5
G52UH 1.42-1.48 14.2-14.8 >1067 >13.5 >1990 >25 390-422 49-53 <180 >7.5
G54UH 1.46-1.51 14.6-15.1 >1075 >13.5 >1990 >25 406-438 51-55 <180 >7.5
G40EH 1.26-1.31 12.6-13.1 >955 >12.0 >2388 >30 302-334 38-42 <200 >7.5
G44EH 1.29-1.35 12.6-13.1 >971 >12.2 >2388 >30 318-350 40-44 <200 >7.5
G46EH 1.33-1.38 12.6-13.1 >1011 >12.7 >2388 >30 334-366 42-46 <200 >7.5
G48EH 1.37-1.42 12.6-13.1 >1027 >12.9 >2388 >30 358-390 45-49 <200 >7.5
G50EH 1.40-1.45 12.6-13.1 >1051 >13.2 >2388 >30 374-406 47-51 <200 >7.5