Zinc Coating Thickness Requirements: ASTM A vs. F Dimension. ASTM A ASTM F Avg. Coating. Thickness of. Specimens. Tested. 23 Feb ASTM F covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special. 4 Jan 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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These instances can include when steel has been severely work hardened or when the galvanizing bath temperature exceeds the stress relief or tempering temperatures of the fasteners. This specification covers the requirements for hot-dip galvanizing on iron and steel products made from rolled pressed and forged shapes, castings, 2f329, bars, and strips. The coating thickness requirements of A Table 1 meet or exceed those of F Table 2 except for:.
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 atsm.
A and F again are more or less the same, F references back to the processes in A, but goes into more detail with respect to the specifics of threaded fasteners. See excerpt of Table 1 below. There are three columns listing the number of test articles for three different inspection tests required under F F defines the two different lots and their associated sampling plans as follows: Spinning removes excess zinc from the fastener so that the nut will mate with the bolt.
ASTM F2329 vs. ASTM A153
This abstract is a brief summary of the referenced standard. Fasteners which are subjected to severe work hardening must be stress-relieved prior to galvanizing. 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. 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. The test methods for appearance and smoothness under F shall be conducted for every batch lot by visual inspection in accordance with methods provided in A The batch lot inspection process is more similar to inspection under A than inspection f232 production lots, but Table 1 ashm F has some additional requirements to consider.
F defines the two different lots and their associated sampling plans as follows:. Electroplating aastm an entirely different process and is a much thinner coating.
Table 2 of F lists average coating thickness requirements for production lots, batch lots, and individual specimens. Furthermore, there are two types of production lots: Suppliers shall furnish certified test results from which the shipping lots originated.
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. Portland Bolt performs hot dip galvanizing of threaded fasteners within our 85, square foot manufacturing facility.
Hot-Dip Galvanizing Specifications
Coating Thickness Table 2 of F lists average coating thickness requirements for production lots, batch lots, and individual specimens. Threaded fasteners are handled differently in order to remove the excess zinc from the threads and would fall under A or F ASTM A does not cover threaded bolts and fasteners. The type of production lot process will determine which column should be referenced for the sample size of each inspection criteria, as summarized in the table below, or per the F Sampling Plan Flow Chart.
If the customer specifies, the galvanizer will be required to provide the average galvanizing temperature the fasteners will be asrm to.
Nails and rivets are not included in this specification. A touches on threaded fasteners, but is not fastener specific. This specification covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, f229, nuts, and special threaded fasteners applied by the hot-dip coating process.
Also in which material we are coating or galavanizing. To determine how many samples are required to test for conformance based on the lot size, F refers to Table 3 of F, Practice for Fastener Sampling astj Specified Mechanical Properties and Performance Inspection. The two specifications have virtually identical coating thickness requirements.
Combining values from the two systems may result in non-conformance with the standard. It is informational only and not an official asrm of g2329 standard; the full text of the standard itself must be referred to for its use and application. Also, A and F have different sampling requirements; F requires more samples per lot than A Best practice is to note the bath temperature when galvanizing steel to F, although only the average bath temperature is required.
Quenching According to F Paragraph 5. Zinc Coating Thickness Requirements: The major differences between the two specifications, described below, include topics related to sampling protocol, coating thickness, inspection, embrittlement, and atm. Therefore, it must be clarified whether the plant has the ability to lubricate hardware after hot-dip galvanizing.
ASTM F – Portland Bolt
ASTM A A covers galvanizing on many products including fasteners, while F is specific to threaded fasteners, nuts and washers. If you are concerned about 2f329 hardness dropping, you could look at alternatives platings that do not require heat, like mechanical galvanizing. The coating thickness requirements of Asgm Table 1 meet or exceed those of F Table 2 except for: April 10, Authored by Bernardo A. Gagan- Sometimes the heat from the hot dip galvanizing operation can slightly soften small hardened items like this.
Aetm us if you have a need for hot-dip galvanized fasteners or with any technical questions regarding hot-dip galvanizing. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.