ASTM F2329/F2329M Hot Dip Zinc Coating for Fasteners

Stud Bolts, Nuts, Screws, Threaded Rod & Washers

ASTM F2329/F2329M specification covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners. It also provides for minor coating repairs. Nails and rivets are not included in this specification.
It is intended to be applicable to fasteners that are centrifuged or otherwise handled to remove excess galvanizing bath metal (free zinc). The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

ASTM F2329/F2329M Material & Manufacturing Process

Condition of the as received Fasteners
Received Fasteners-The fasteners as received by the galvanizer shall be free from contaminants that are not readily removed in the cleaning process and would adversely affect the galvanizing.
Process
Unless otherwise covered in this specification, all processing parameters shall be in accordance with the requirements of Specification A153/A153M.
Process Control
Galvanized fasteners subjected to a process control plan based upon batch lot level shall comply with the batch lot sampling plan in Table 1, and the sampling plan for production lot (prevention process) as determined in 10.2.2 shall be applied.
Process Control of Batch LotA Sampling Plan

ASTM F2329/F2329M Coating & Dimensional Requirements

Coating Thickness
The zinc coating thickness shall meet the requirements of table below. See Supplementary Requirement S1 when specifying coating thickness for fasteners meeting the requirements of Specification A394.
Zinc Coating Thickness

ASTM F2329/F2329M Testing Methods

Tests shall be made to ensure that the zinc coating is being furnished in accordance with this specification and as specified for the following :

Coating Thickness
Average Coating Thickness on an Individual Specimen – To calculate the average coating thickness of one specimen, a minimum of five readings shall be taken. In case the geometry of the specimen does not permit five readings, five test specimens shall be used to establish the average reading. The determination of the coating thickness shall be made on a portion of the fastener that does not include any threads in accordance with Practice E376. In case of arbitration, the thickness of coating shall be determined cross section and optical measurement, in accordance with Test Method B487. Thus, the thickness determined is a point value. No less than five measurements shall be made at locations on the test specimen, which are as widely dispersed as practical, so as to be representative of the whole surface of the test specimen. The average of those selected measurements is the average coating thickness.
Finish and Appearance
Finish and appearance shall be visually inspected.
Embrittlement Test
If the product standard requires testing for hydrogen embrittlement of galvanized fasteners, testing shall be done in accordance with Test Methods F606/F606M or other test method(s), as required the purchaser.
Adhesion Test
Testing for adherence shall be conducted as determined in the section on Adherence of Specification A153/A153M.