Zinc Coating Thickness Requirements: ASTM A vs. F Dimension. ASTM A ASTM F Avg. Coating. Thickness of. Specimens. Tested. ASTM F covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special. ASTM A does not cover threaded bolts and fasteners. ASTM A and F are the ASTM specifications that cover the requirements for.
A summary of the numerical differences between the two specifications related to coating thickness requirements for all materials is presented in the table: The batch lot inspection process is more similar to inspection under A than asm of production lots, but Table 1 of F has some additional requirements to consider.
The following tests shall be made to ensure that the zinc coating is being furnished in accordance with this specification: The standard specification that covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners applied by the hot-dip coating process. It also provides for minor coating repairs.
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Average Thickness of Individual Specimen 0. For each of these types, there are also inspection criteria for coating thickness, visual appearance, and adhesion.
It does not cover astmm fasteners that are centrifuged or otherwise handled to remove excess zinc. Each bolt specification may list additional methods to prevent hydrogen embrittlement as well as place additional requirements on embrittlement testing which should be researched separately.
The major differences between the two specifications, described below, include topics related to sampling protocol, coating thickness, inspection, embrittlement, and documentation. ASTM F The standard specification that covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners applied by the hot-dip coating process.
Current edition approved Feb. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. F defines the two different lots and their associated sampling plans as follows:. Galvanizing fasteners in accordance with A, will usually meet or exceed the requirements of F, because F defers to A in many sections.
The zinc used for the coating shall conform to the chemical composition required. NOTE 2—Hot-dip washers tend to bond to each other. Minor roughness that does not impair the intended use of the part, or roughness that is related to the uncoated surface condition of the part, shall not constitute grounds for rejection of the parts.
Also, A and F have different sampling requirements; F requires more samples per lot than A I am having difficulty determining the hot dip zinc coating needed for an anchor bolt 60M 60mm and 1. Otherwise, a third party will be required to apply the lubricant at an additional cost.
If the galvanizing process is carried out at a higher temperature than the stress relief or the tempering temperature of the fasteners, than the purchaser shall make provision for mechanical testing. Best practice is to note the bath temperature when galvanizing steel to F, although only the average bath temperature is required.
ASTM F vs. ASTM A | American Galvanizer’s Association
Fasteners and nuts over 3? In no case shall the average reading of a single specimen be below the average thickness shown in the Average Thickness on Individual Specimen column. Adhesion testing is not typically performed when galvanizing to the requirements of A unless there is evidence of an adhesion concern, but F requires adhesion testing stout knife test to be performed for the number of articles listed in Table 1, and for every batch lot.
April 10, Authored by Bernardo A. Suitable acceptance criteria shall be agreed between the purchaser and the galvanizer before placing the order. The average of those selected measurements is the average coating thickness. For example, a lot size of articles under the detection process requires testing of 11 samples for coating thickness, 11 samples for visual appearance, and 3 samples for adhesion.
Hot-Dip Galvanizing Specifications
Threaded fasteners are handled differently in order to remove the excess zinc from the threads and would fall under A or F Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. F f22329 05 Standard Speci? A number in parentheses indicates the year of last reapproval. Also in which material we are coating or galavanizing.