Here are some talking points........... Could a manufacturer offer a new, classic looking line of true magnesium wheels today or would there be too many "liability" issues? Is there any reason they couldn't be within 2 or 3 times the cost of aluminum?
Most race sanctioning organizations don't permit "real" old magnesium wheels due to long-term inter-granular micro-corrosion/separation with age, resulting in structural weakness and shear failure. They're pretty, but don't race on them!
That is the first I’ve heard of them. They don’t have the one halibrand wheel I’m looking for but still that is pretty awesome. Sent from my iPhone using The H.A.M.B. mobile app
Lots of guys still race on mag wheels. I do on five spoke fronts and bear claws on the rear. I have a second set of bear claws for street tires. They are all polished to a mirror finish. I started with good wheels. Finding a set without corrosion is the key.
Are the bear claws on the rear an “older style?” A quick search and yours are the only ones I’ve seen. I dig the look and how they shine up. Sent from my iPhone using The H.A.M.B. mobile app
there was only one style and i believe two different widths 10 inch and 13 inch. all were made 16 inch diameter. they were never produced for a 15 inch tire. they came out around 67 through early 70s. dont quote me on that. made by american.
I got this one to make a clock out of magnesium wheels are awesome but to keep them polished is consistent upkeep
Many a time I heard a member of the "unwashed" general population refer to any old hot rod as a "roadster".
pirate most of your information on mag wheels is incorrect. the powder that forms from corrosion is white not gray. magnesium is very hard. it wears out tooling when machined its so hard. as far as a dull gold after a dow-7 treatment that depands on the finish of the wheel prior to said treatment. a polished wheel will turn out bright gold. a as cast or rough wheel will turn out dull. as far as your comment on street driving causing damage regardless of the wheel if you curb one they will show damage just like a aluminum wheel. im sure all of your comments are not based on personel experience otherwise you would not need to be told how it is. this coming from a guy that owns several sets of mag wheels that street drives and races on them.
“this coming from a guy that owns several sets of mag wheels that street drives and races on them.[/QUOTE] Any chance you have some pictures you can share? If they look half as good as the polished ones you have they would be worth posting! Sent from my iPhone using The H.A.M.B. mobile app
There`s been about 5 pairs or so listed in the HAMB classifieds for sale since I started this thread. Coincidence ?
No coincidence. Threads talking about them make all the non-owners want some, so the sellers see the market growing. Usually the people selling the magnesium wheels have a good pile of them already, and are passing on the wheels with the size or bolt pattern they don't need. As a collector of any rare item knows, you need to buy what's available when you see it. Sometimes you end up with some extras.
Sure here are both versions street and race. Nothing to hide here. The car has gone almost 200 mph on the race version. The car has seen thousands of miles doing drag week; summit midwest drag and drive events and countless other drives on the street with the other set. If the wheels were subject to failure they would have broken a long time ago.
Well as an engineer I tend to deal in facts rather then opinion. If you care to read the following information you will find that aluminum has a higher tensile strength, higher yield strength and higher elongation. These three mechanical properties are usually used to determine the strength of a metal. Aluminium Alloy vs Magnesium Alloy – Comparison – Pros and Cons Contents [show] Aluminium Alloys High purity aluminium is a soft material with the ultimate strength of approximately 10 MPa, which limits its usability in industrial applications. Aluminium of commercial purity (99-99.6%) becomes harder and stronger due to the presence of impurities, especially of Si and Fe. But when alloyed, aluminium alloys are heat treatable, which significantly changes theri mechanical properties. Aluminium alloys are based on aluminium, in which the main alloying elements are Cu, Mn, Si, Mg, Mg+Si, Zn. Aluminium alloy compositions are registered with The Aluminum Association. The aluminium alloys are divided into 9 families (Al1xxx to Al9xxx). The different families of alloys and the major alloying elements are: 1xxx: no alloying elements 2xxx: Copper 3xxx: Manganese 4xxx: Silicon 5xxx: Magnesium 6xxx: Magnesium and silicon 7xxx: Zinc, magnesium, and copper 8xxx: other elements which are not covered by other series There are also two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. Aluminium alloys containing alloying elements with limited solid solubility at room temperature and with a strong temperature dependence of solid solubility (for example Cu) can be strengthened by a suitable thermal treatment (precipitation hardening). The strength of heat treated commercial Al alloys exceeds 550 MPa. Mechanical properties of aluminium alloys highly depend on their phase composition and microstructure. High strength can be achieved among others by introduction of a high volume fraction of fine, homogeneously distributed second phase particles and by a refinement of the grain size. In general, aluminium alloys are characterized by a relatively low density (2.7 g/cm3 as compared to 7.9 g/cm3 for steel), high electrical and thermal conductivities, and a resistance to corrosion in some common environments, including the ambient atmosphere. The chief limitation of aluminum is its low melting temperature (660°C), which restricts the maximum temperature at which it can be used. For general production the 5000 and 6000 series alloys provide adequate strength combined with good corrosion resistance, high toughness and ease of welding. Aluminium and its alloys are used widely in aerospace, automotive, architectural, lithographic, packaging, electrical and electronic applications. It is the prime material of construction for the aircraft industry throughout most of its history. About 70% of commercial civil aircraft airframes are made from aluminium alloys, and without aluminium civil aviation would not be economically viable. Automotive industry now includes aluminium as engine castings, wheels, radiators and increasingly as body parts. 6111 aluminium and 2008 aluminium alloy are extensively used for external automotive body panels. Cylinder blocks and crankcases are often cast made of aluminium alloys. Magnesium Alloys Pure magnesium is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table. Magnesium alloys are mixtures of magnesium and other alloying metal, usually aluminium, zinc, silicon, manganese, copper and zirconium. Since the most outstanding characteristic of magnesium is its density, 1.7 g/cm3, its alloys are used where light weight is an important consideration (e.g., in aircraft components). Magnesium has the lowest melting point (923 K (1,202 °F)) of all the alkaline earth metals. Pure magnesium has an HCP crystal structure, is relatively soft, and has a low elastic modulus: 45 GPa. Magnesium alloys have also a hexagonal lattice structure, which affects the fundamental properties of these alloys. At room temperature, magnesium and its alloys are difficult to perform cold working due to the fact plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminium, copper and steel. Therefore, magnesium alloys are typically used as cast alloys. Despite the reactive nature of the pure magnesium powder, magnesium metal and its alloys have good resistance to corrosion. Aluminium is the most common alloying element. Aluminium, zinc, zirconium, and thorium promote precipitation hardening: manganese improves corrosion resistance; and tin improves castability. We must add, pure magnesium is highly flammable, especially when powdered or shaved into thin strips, though it is difficult to ignite in mass or bulk. It produces intense, bright, white light when it burns. Flame temperatures of magnesium and some magnesium alloys can reach 3,100°C. Burning or molten magnesium reacts violently with water. Once ignited, such fires are difficult to extinguish, because combustion continues in nitrogen (forming magnesium nitride), carbon dioxide (forming magnesium oxide and carbon), and water. Burning magnesium can be quenched by using a Class D dry chemical fire extinguisher. Its flammability is greatly reduced by a small amount of calcium in the alloy. Uses of Magnesium Alloys – Application Forged magnesium wheels Magnesium alloys are used in a wide variety of structural and nonstructural applications. Structural applications include automotive, industrial, materials-handling, commercial, and aerospace equipment. Magnesium alloys are used for parts that operate at high speeds and thus must be light weight to minimize inertial forces. Commercial applications include hand-held tools, laptops, luggage, and ladders, automobiles (e.g., steering wheels and columns, seat frames, transmission cases). Magnox (alloy), whose name is an abbreviation for “magnesium non-oxidizing”, is 99% magnesium and 1% aluminum, and is used in the cladding of fuel rods in magnox nuclear power reactors. Properties of Aluminium Alloy vs Magnesium Alloy Material properties are intensive properties, that means they are independent of the amount of mass and may vary from place to place within the system at any moment. The basis of materials science involves studying the structure of materials, and relating them to their properties (mechanical, electrical etc.). Once a materials scientist knows about this structure-property correlation, they can then go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final form. Density of Aluminium Alloy vs Magnesium Alloy Density of typical aluminium alloy is 2.7 g/cm3 (6061 alloy). Density of typical magnesium alloy is 1.8 g/cm3 (Elektron 21). Density is defined as the mass per unit volume. It is an intensive property, which is mathematically defined as mass divided by volume: ρ = m/V In words, the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance. The standard SI unit is kilograms per cubic meter (kg/m3). The Standard English unit is pounds mass per cubic foot (lbm/ft3). Since the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance, it is obvious, the density of a substance strongly depends on its atomic mass and also on the atomic number density (N; atoms/cm3), Atomic Weight. The atomic mass is carried by the atomic nucleus, which occupies only about 10-12 of the total volume of the atom or less, but it contains all the positive charge and at least 99.95% of the total mass of the atom. Therefore it is determined by the mass number (number of protons and neutrons). Atomic Number Density. The atomic number density (N; atoms/cm3), which is associated with atomic radii, is the number of atoms of a given type per unit volume (V; cm3) of the material. The atomic number density (N; atoms/cm3) of a pure material having atomic or molecular weight (M; grams/mol) and the material density (⍴; gram/cm3) is easily computed from the following equation using Avogadro’s number (NA = 6.022×1023 atoms or molecules per mole): Crystal Structure. Density of crystalline substance is significantly affected by its crystal structure. FCC structure, along with its hexagonal relative (hcp), has the most efficient packing factor (74%). Metals containing FCC structures include austenite, aluminum, copper, lead, silver, gold, nickel, platinum, and thorium. Mechanical Properties of Aluminium Alloy vs Magnesium Alloy Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial and engineers must take them into account. Strength of Light Aluminium Alloy vs Magnesium Alloy In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformation or change in material dimensions. Strength of a material is its ability to withstand this applied load without failure or plastic deformation. Ultimate Tensile Strength Ultimate tensile strength of 6061 aluminium alloy depends greatly on the temper of the material, but for T6 temper it is about 290 MPa. Ultimate tensile strength of Elektron 21 – UNS M12310 is about 280 MPa. The ultimate tensile strength is the maximum on the engineering stress-strain curve. This corresponds to the maximum stress that can be sustained by a structure in tension. Ultimate tensile strength is often shortened to “tensile strength” or even to “the ultimate.” If this stress is applied and maintained, fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after the ultimate strength has been achieved. It is an intensive property; therefore its value does not depend on the size of the test specimen. However, it is dependent on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature of the test environment and material. Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels. Yield Strength Yield strength of 6061 aluminium alloy depends greatly on the temper of the material, but for T6 temper it is about 240 MPa. Yield strength of Elektron 21 – UNS M12310 is about 145 MPa. The yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. Prior to the yield point, the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behaviour termed a yield point phenomenon. Yield strengths vary from 35 MPa for a low-strength aluminum to greater than 1400 MPa for very high-strength steels. Young’s Modulus of Elasticity Young’s modulus of elasticity of 6061 aluminium alloy is about 69 GPa. Young’s modulus of elasticity of Elektron 21 – UNS M12310 is about 45 GPa. The Young’s modulus of elasticity is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to a limiting stress, a body will be able to recover its dimensions on removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position. All the atoms are displaced the same amount and still maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions and no permanent deformation occurs. According to the Hooke’s law, the stress is proportional to the strain (in the elastic region), and the slope is Young’s modulus. Young’s modulus is equal to the longitudinal stress divided by the strain. Hardness of Aluminium Alloy vs Magnesium Alloy Brinell hardness of 6061 aluminium alloy depends greatly on the temper of the material, but for T6 temper it is approximately 95 MPa. Brinell hardness of Elektron 21 – UNS M12310 is approximately 70 HB. Rockwell hardness test is one of the most common indentation hardness tests, that has been developed for hardness testing. In contrast to Brinell test, the Rockwell tester measures the depth of penetration of an indenter under a large load (major load) compared to the penetration made by a preload (minor load). The minor load establishes the zero position. The major load is applied, then removed while still maintaining the minor load. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number. That is, the penetration depth and hardness are inversely proportional. The chief advantage of Rockwell hardness is its ability to display hardness values directly. The result is a dimensionless number noted as HRA, HRB, HRC, etc., where the last letter is the respective Rockwell scale. The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg. Thermal Properties of Aluminium Alloy vs Magnesium Alloy Thermal properties of materials refer to the response of materials to changes in their temperature and to the application of heat. As a solid absorbs energy in the form of heat, its temperature rises and its dimensions increase. But different materials react to the application of heat differently. Heat capacity, thermal expansion, and thermal conductivity are properties that are often critical in the practical use of solids. Melting Point of Aluminium Alloy vs Magnesium Alloy Melting point of 6061 aluminium alloy is around 600°C. Melting point of Elektron 21 – UNS M12310 is around 550 – 640°C. In general, melting is a phase change of a substance from the solid to the liquid phase. The melting point of a substance is the temperature at which this phase change occurs. The melting point also defines a condition in which the solid and liquid can exist in equilibrium. Thermal Conductivity of Aluminium Alloy vs Magnesium Alloy The thermal conductivity of 6061 aluminium alloy is 150 W/(m.K). The thermal conductivity of Elektron 21 – UNS M12310 is 116 W/(m.K). The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note that Fourier’s law applies for all matter, regardless of its state (solid, liquid, or gas), therefore, it is also defined for liquids and gases. The thermal conductivity of most liquids and solids varies with temperature. For vapors, it also depends upon pressure. In general: Most materials are very nearly homogeneous, therefore we can usually write k = k (T). Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz), but for an isotropic material the thermal conductivity is independent of the direction of transfer, kx = ky = kz = k.
The fact is the corrosion is white and the pictures prove it. Apparently the Porsche and Ferrari engineers dont know a thing because they put mag wheels on their cars along with others. All the engineering is cool it still comes down to does it work for the application. Mag wheels work for street and race cars. Your post left out how my wheels have been able to do their thing for the last 50 years if they are not engineered for the job.
Kinda the essence of most of hot rodding. Taking something not meant for the job and making it work. And sometimes it works very well.
Read @pirate 's post, slowly, twice. Always glad to gain information. The greater part sunk in. Actual laboratory tests would have to be done on Mag wheels to learn if they're overbuilt enough to last. Mine will stay on the car, guess that's the chance this hoodlum's gonna take! @racer-x has done real world testing for us. Any documented failures out there?
I'm sure there are failures out there. Moisture is mags worst enemy. Using a overly corroded wheel or one damaged do to a accident could surely cause a failure. A friend of mine works in the aircraft repair industry. He has access to a magnuflux machine. He checks his regularly. I have mine polished not only for looks but to also see if I get a crack. I'm always polishing them so I'm very in tune with their condition. Back in the early days of custom wheels there were some good wheels and some cheap imitations. The cheap imitations were prone to failure and gave custom wheels a bad name. I have yet to see a cheaply made mag wheel. They dont have thin areas where they mount or have thin spokes. Staying with american or halibrand would be my recomendation.
Yeah Bowie, I've always loved old mag wheels too. My neighbor is always asking. When you gonna paint that coupe, and put some chrome wheels on it. I say maybe someday. Lol I've always like the old mag wheels. Sometimes you can find them cheap, and a lot of the time just find one only. Sometimes it may take years to fine it's mate, and the bolt pattern never matters. Then on the other hand, and more so now days. The owner thinks they are made of gold, and not magnesium. Easyest way to know a real mag is the light weight. Years ago I used to try and keep them polished. But not anymore. I never over think this stuff. I do know they are a part of our great Hot Rod history. Ron....
One of the major reasons for banning mag wheels for racing was do to the fire danger. Once on fire only purple-k will put it out. Putting water on a mag fire makes it burn faster. Throw a old lawn boy mag lawn mower deck on your next camp fire. Then throw a bucket of water on when it starts to burn. Have your welding glasses on as it gets very bright. Mag interior panels are also banned for obvious reasons. Not because they are worried about a crack.
It's a light grey, but I could see how one thinks it looks white. Magnaflux (magnetic particle) testing is done on ferrous metals. He's not testing his non-ferrous magnesium with it. He may be using Magnaflux's penetrant dyes to check for cracks in his magnesium, which is a completely different process and material. Yes, straight H2O will exacerbate a magnesium fire. It's classified as a Class D (metal) fire. "Purple-K" is intended for use on Class B (liquid/gas) and some Class C (electrical) fires; it's not really the appropriate suppressant for a magnesium fire. It is a dry-chemical suppressant, where-as a Class D fire should be extinguished with a dry-powder suppressant. A magnesium fire should be extinguished with a sodium chloride or graphite-based suppressant, among others.
The Jalopy Journal
