Aluminum metal fasteners and fastener strength characteristics compare

Weight aluminum fasteners is their similar steel fasteners 1/3 of the weight. Strength characteristics of this alloy is often used surprisingly good. In fact, the strong - quality ratio, aluminum fastener fasteners than any other kind of material to use and Trade to be higher. Aluminum is non-magnetized. Thermoelectric conductivity of aluminum is very good, about the same volume of copper conduction properties of 2/3. Aluminum has good processing characteristics, easy to cold forming and forging.

Compared with aluminum fasteners metal fasteners strength characteristics:

Externally threaded fasteners aluminum alloy 2024-T4,6061-T6 and 7075-T73 strength characteristics in ASTMF468 B-158 page have specifically addressed; nut aluminum alloy 2024-T4,6061-T6 and 6062-T9's strength features are specifically addressed in ASTMF467 B-184 page.

Here it is necessary to explain aluminum alloy material threaded fasteners and other metal fasteners points difference in mechanical properties.

The first point is this: When calculating load capacity of parts, to be determined cross-sectional area of the bottom portion of the tooth instead of the tensile stress area larger area. Only in ASTMF468 table 2 in a given sample tensile mechanical testing, yield strength values is the real strength values. In the entire size of the fastener do strength calculations, we can make the appropriate adjustments. So when the stress and the threaded area of the force in pounds multiplied to calculate the load capacity of the unit, the results about the table that is 'real value' and a smaller area of the tooth bottom of the product.

The second point is the difference between the hardness of the aluminum alloy is small, but the same guidelines as the examination does not make sense. As an alternative to the hardness test, usually the introduction of shear strength tests.

2024-T4 aluminum alloy (containing 4.5% copper, 1.6% manganese, 1.5% magnesium, balance aluminum) alloy is heavy. It reached a perfect balance in the combination of strength, corrosion resistance, manufacturability, economical, widely used in the manufacture of threaded fasteners.

With the 7075-T73 aluminum alloy (containing 1.6% copper, 2.5% manganese, 0.3% chromium, the balance aluminum) bolts, screws and studs with small progress made on the strength, but also because ' T73 'special heat treatment process, so that it can prevent the occurrence of stress corrosion in large part. But the popularity of the expensive cost of it is limited.

6061-T6 aluminum alloy (containing 0.6% silicon, 0.25% copper, 1% magnesium, 0.2% chromium, the balance aluminum) can be used to design against corrosion have higher expectations inner and outer threaded fastener .

6062-T9 aluminum alloy (containing 0.6% silicon, 0.25% copper, 1% magnesium, 0.09% chromium, 0.5% of lead, the balance aluminum) was almost exclusive design nut. This alloy 6061-T6 aluminum alloy than the higher intensity and a relatively good corrosion resistance.

6062-T9 aluminum alloy made of full thickness nut has sufficient strength to fit bolt 2024-T4 or 7075-T73 aluminum alloy made. Machine screws, nuts and other 1/4 inch and smaller size of the nut-type aluminum alloy 2024-T4.

Aluminum for fasteners manufacturing advantages

Four aluminum already mentioned in the threaded fastener carrying the most widely used in the manufacture, while others are used for other types of aluminum alloy fasteners manufacturing. Small solid, half-pipes and blind rivets respectively, by 1100-F, 5052-F, 5056-F-type aluminum alloy obtained. Can be heat-treated 2017-T4,2117-T4,2024-T4,6061-T6 aluminum alloy and developed a relatively new type of aluminum alloy 7075-T73 has a superior shear strength, and do not need to 'pre-transmission processing' on I can drive.

Flat washers are usually made from aluminum alloy of 2024-T4; coil spring washer 7075-T6 alloy usually prepared; tapping screw may use 7075-T6 alloy system; self-tapping screws from the same alloy material obtained by anodizing. 2011-T3 aluminum alloy (containing 5.5% copper, 0.5% lead and 0.5% bismuth, the balance aluminum) can be used to make thread cutting machine parts.

Under normal circumstances, aluminum has sufficient corrosion resistance. And when the expected exposure environment is very bad, its corrosion resistance can be greatly improved by anodizing. Anodizing is an electrical process a metal oxide film formed on the surface. Anodized not only enhances the corrosion resistance, but also enhance the wear and scratch protection. Anodic coating for decorative purposes and has identified a variety of colors. In the atmospheric corrosion, the aluminum on the surface layer of light gray oxide film. These corrosion products does not contaminate the surface of aluminum, or spread onto adjacent surfaces, it and many other metals behave in a corrosive effect is not the same at this point.

The tensile strength of pure aluminum is about 13,000psi, a small amount of alloying elements greatly increase the intensity of progress is possible. 2XXX, 6XXX, 7XXX aluminum alloys for heat treatment works well. Thus, virtually all it threaded fasteners for load transfer of these three categories by an aluminum alloy. There are four kinds of aluminum is almost exclusive.