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.
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Contact us if you have a need for hot-dip galvanized fasteners or with any technical questions regarding hot-dip galvanizing. Threaded fasteners are handled differently in order to remove the excess zinc from the threads and would fall under A or F 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.
Also in which material we are coating or galavanizing. Zinc Coating Thickness Requirements: In addition, the purchaser shall provide fasteners having sufficient dimensional allowance to accommodate the zinc thickness deposition, as required in 8. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. This process involves the removal of excess zinc by spinning the parts in a centrifuge, or brushing the threaded portion, or handling otherwise to t2329 the excess zinc.
Packaging and Package Marking It does not cover threaded fasteners that are centrifuged or otherwise handled to f239 excess zinc. Materials and Manufacture 5. Rob- Tensioning the bolt will not adversely affect the galvanizing.
It is necessary for the galvanizer to communicate the bath temperature to the customer to ensure the end user understands the effects the galvanizing temperature will have on the steel. A superscript epsilon e indicates an editorial asrm since the last revision or reapproval.
ASTM F vs. ASTM A | American Galvanizer’s Association
Suitable acceptance criteria shall be agreed between the purchaser and the galvanizer before placing the order. Historical Version s – view previous versions of standard. According to Note C of Table 1, It is only required to conduct testing on samples for coating thickness once every five batch lots.
Since threaded fasteners are spun at high speeds in a centrifuge to remove excess zinc from the threads, they would fall under the A class C specification. 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 f232 mechanical testing. Best practice is to note the bath temperature when galvanizing steel to F, although only the average bath temperature is required.
The coating thickness requirements of A Table 1 meet or exceed those of F Table 2 except for:. Furthermore, the galvanizer shall not be held responsible for any unanticipated distortion of parts. In no case shall the average of the measurements be below the average thickness shown in the Average Thickness on Individual Specimen column see The values stated in each system may asgm be exact equivalents; therefore, each system shall be used independently of the other.
The amount of additional documentation beyond ASTM A requirements will vary depending on a number of optional requirements the customer can specify under F Unless otherwise agreed to in the purchase order, delivered galvanized washers shall not be bonded to each other. Authored by Alana Hochstein. F defines the two different lots and their associated sampling plans as follows:.
Furthermore, there are two types of production lots: It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. When requested by the purchaser, the average galvanizing temperature that the fasteners will be subjected to shall be furnished. This specification covers the requirements for hot-dip galvanizing on iron and steel products made from rolled asmt and forged shapes, castings, plates, bars, and strips.
In addition, small parts shall be air cooled as needed in order to prevent the formation of zinc oxide. In case the geometry of the specimen does not permit? The average of those selected measurements is the average coating thickness.
F defines the two different lots and their associated sampling plans as follows: D Visual inspection for conformance.
These requirements astk established by the applicable satm standard, such as Speci?
Hot-Dip Galvanizing Specifications
The major differences between the two specifications, described below, include topics related to sampling protocol, coating thickness, inspection, embrittlement, and documentation. Zstm touches on threaded fasteners, but is not fastener specific. Vinay- ASTM A and A both say that the maximum service temperature for galvanized bolts should not exceed Asttm unless caution is used in regard to the potential for liquid hydrogen embirittlement.
Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. If you are concerned about the hardness dropping, you could look at alternatives platings that do not require heat, like mechanical galvanizing.
The batch lot inspection process is more similar to inspection under A than inspection of production lots, but Table 1 of F has some additional requirements to t2329.