Astm 123a123m specification reflects new coating grades for plate steel, which is now a separate material category from structural shapes, new coating thicknesses for strip and bar, and a new column for steel thickness of 58 16 mm for all material categories. The requirements for astm a153a153m are very similar to those stated earlier for astm a123 a123m, except for the addition of threaded products and embrittlement requirements. Astm a123 a123m, standard specification for zinc hot dip galvanized coatings on iron and steel products, astm international, west conshohocken, pa, 20. Astm a123 a123m09, standard specification for zinc hot dip galvanized coatings on iron and steel products, astm international, west conshohocken, pa, 2009. A123 a123m17 standard specification for zinc hotdip galvanized coatings. Astm f2329 covers the requirements for hotdip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners applied by the hotdip coating process. The requirements listed in astm a123 a123m include coating thickness, finish, appearance, and adherence. Astm a123 and g90 specifications american galvanizers. The link below is a service life chart showing the coating life versus coating thickness for a hot dip galvanized astm a123 coating. The astm a123 a123m17 document details specifications for materials, including the steel or iron, zinc, and bath composition, and coating properties, such as the coating thickness, finish, and appearance.
Astm a123 a123m standard specification for zinc hot. For small projects less than 20 tons, it is not likely that the fabricator has the selectivity to order steel of speci. But there is a practical maximum, defined by physical things that happen when coating is thick, or by the cost of obtaining a thick coating. This specification is for hotdip galvanizing steel sheet using the continuous highspeed galvanizing process. Coating thickness weight depends on the material category and steel thickness, values are listed in table 3. Corrosion protection hot dip galvanizedastm a153 vs b633. Astm a123 a123m 17 standard specification for zinc. While the steel is in the kettle, the iron in the steel metallurgically reacts with the molten zinc to form a tightlybonded alloy coating that provides superior corrosion protection to steel. It is intended to be applicable to fasteners that are centrifuged or otherwise handled to remove excess zinc. Astm a123 for structural steel american galvanizers. Or is there other standards that can be looked at in relation to being hot dipped galvanized. The equivalent aashto specification to astm a153 is aashto m232. The minimum average coating thickness grade for any specimen shall be one coating grade below that required for the appropriate material category and thickness in table 1.
Oct 10, 2001 astm a123 a123m01 standard specification for zinc hotdip galvanized coatings on iron and steel products october 10, 2001 astm international 1. Astm a123 a123m 09 standard specification for zinc. The hotdip galvanizing process consists of parts being immersed in molten zinc for a sufficient time to allow a metallurgical reaction between iron from the steel surface and the molten zinc, resulting in the formation of znfe alloy layers bonding the coating to the steel surface. Astm a123 a123m02 standard specification for zinc hotdip galvanized coatings on iron and steel products.
Astm a123 a123m zinc coatings on iron and steel products this specification covers the requirements for zinc coating galvanizing by the hotdip process on iron and steel products made from rolled pressed and forged shapes, castings, plates, bars, and strips. B487 test method for measurement of metal and oxide coating thickness by microscopical examination of cross section. Astma123standardspecificationforzinccoatingsoniron. Materials galvanized per astm a123 can be used to specify zinc coatings up to 2. For standard structural shapes and plates, astm a123123m requires a minimum average coating thickness of 3. A reproduction and summary of the table given in astm a153 a153m, table. The coating weight increases with material thickness. This specification covers the standard requirements for hotdip galvanized zinc coatings on iron and steel products made from rolled pressed and forged shapes, castings, plates, bars, and. In addition to defining coating, thickness, finish, and appearance, astm a123 dictates an adherence requirement for the entire coating. Hotdip galvanizing to astm a123 fact sheet hotdip galvanizing hdg is the process of dipping fabricated steel into a kettle or vat containing molten zinc. Materials galvanized per astm a153 class b require an average weight of zinc coating to be 2.
Material category, all tested samples thickness measured in mm in. Thick galvanized coatings, how to get, what is maximum. Zinc hotdip galvanized coatings on iron and steel products1. Astm a123 for structural steel american galvanizers association. Nonmagnetic coatings on magnetic basis metals1 this standard is issued under the. Standard test method for measurement of coating thicknesses. Standard test method for measurement of metal and oxide.
Astma123 standard specification for zinc hotdip galvanized coatings on iron and steel products astm a123 2017 edition current see the following. Galvanizing thickness measurement resources defelsko. The batch hot dip galvanized coating is described as the coating mass gm 2 or thickness m or commonly stated as microns on a single surface. New changes to astm a123 american galvanizers association. Coating thickness weight dependent upon material category and steel thickness. Astm a123 a123m 17 standard specification for zinc hot. Because the coating thickness is determined by thickness of steel and steel chemistry, galvanizers have little, if any, control over the thick ness of the coating obtained.
Astm a 153 zinc coating on iron and steel hardware. In most cases it is easier to measure the thickness of the coating, but the historical way of specifying the coating is by a mass designation. For a unit of product whose surface area is equal to or less than 160 in. Astm b487 standard test method for measurement of metal and oxide coating thickness by microscopical examination of cross section published by astm on february 22, 1985 this test method covers measurement of the local thickness of metal and oxide coatings by the microscopical examination of cross sections using an optical microscope. B487 test method for measurement of metal and oxide coating thickness by. Astm a123 covers the requirements for zinc coating galvanizing by the hotdip process on iron and steel products made from rolled pressed and forged shapes, castings, plates, bars, and strips. Astm a123 a123m17, standard specification for zinc hot dip galvanized coatings on iron and steel products, astm international, west conshohocken.
The coating grade is defined as the required thickness of the coating and is given in microns. The coating thickness on any surface will be at least 5 times the thickness and service life of a g90 coating. The standard requires a strong level of adherence throughout the service life of the galvanized steel. Standard test method for measurement of coating thicknesses by the magnetic method. In atmospheric environments, the time to first maintenance of hotdip galvanized steel is directly proportional to the thickness of the hotdip galvanized coating. Standard specification for zinc hotdip galvanized coatings on iron and steel products1 this standard is issued under the fixed designation a 123a 123m. Madden bolt uses a proprietary adherence process that meshes our zinc coating with the steel product for. The following bibliographic material is provided to assist you with your purchasing decision. This specification covers the requirements for zinc coating galvanizing by the hotdip process on iron and steel products made from rolled pressed and forged shapes, castings, plates, bars, and strips. Astm a123 hot dip galvanized pipe elbows,astm a123 hot dip. Astm a123a123m15 standard specification for zinc hotdip. Standard test method for measurement of metal and oxide coating thickness by microscopical examination of cross section1 this standard is issued under the. The result is a pure zinc coating best suited to mild indoor exposures.
Astm a123 or astm a153 and astm a385 2 is it practical to specify steel of certain chemistry in order to better control the coating thickness and appearance. Most standards state a minimum thickness for galvanizing, and no maximum. Thickness or weight of zinc coating for various classes. Astm 123a123m specification reflects new coating grades for plate.
Th e batch hotdip galvanizing process, also known as general galvanizing, produces a zinc coating on iron and steel products by immersion of the material in a bath of liquid zinc. But g164 has its own test procedures for the weakening of the base layer, a123 refers to the most complete guide of the astm a143 standard, which gives the details of a bending. The hotdip process requirements for astm a123 a123m are based on coating thickness, finish, appearance and adherence for iron and steel products. Astm a123a123m standard specification for zinc hotdip galvanized coatings on iron and steel products. Astm a153 for hardware american galvanizers association.
This specification has been prepared by the galvanizing industry through its technical working group, in consultation with industry and a number of consulting engineering groups. In addition, it addresses sampling and test methods to assure that the zinc coating is being furnished properly. Oct 10, 2001 astm a123 a123m02 standard specification for zinc hotdip galvanized coatings on iron and steel products october 10, 2002 astm international 1. E376 practice for measuring coating thickness by magneticfield or eddycurrent electromagnetictesting methods 1 this speci. Average minimum thickness of the coating by material category. Once again, the service life will be a function of the environment that the coating is exposed to. Standard coating thickness according to astm a123 a123m.
All coating thickness requirements in specification astm a123 a123m, tables 1 and 2, are minimums. Oct 12, 2017 the astm a123 a123m17 document details specifications for materials, including the steel or iron, zinc, and bath composition, and coating properties, such as the coating thickness, finish, and appearance. Specifications frontier hot dip galvanizing buffalo, ny. Astm a123 also has a few more requirements concerning the coatings finish. Both specifications require the use of a knife test to determine proper coating adherence. Production processes for zinc coatings batch hotdip galvanizing.
Service life is defined as the time to 5% rusting of the steel surface. Materials and coatings available for wood construction. Astm a123 is a related hotdip galvanizing specification covering iron and steel products made from rolled and pressed shapes, castings, plates, bars, and strips. Astm a123, standard specification of zinc hotdip galvanized coatings on iron and steel products, refers to products fabricated and then hotdip galvanized. A123 a123m17 standard specification for zinc hot dip galvanized coatings on iron and steel products hotdip galvanizing zinc coating steel plates steel strips steel bars steel forgings zinccoated steel products. Astm a123 a123m zinc coatings on iron and steel products.
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