The fastener industry should be made aware of an important recent development in the realm of. ASTM fastener standard specifications. ASTM F/. “ASME Hex Nut, 3/8 UNC-2B, SAE J Grade 5, ASTM F Zinc Coating ZN/FE Type 5B” we simply specify: “grade 5, zinc plated. ASTM F/FM: Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric.
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Nonmagnetic Coatings on Aatm Basis Metals. Test Method F is a recognized veri? It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. Refer to Annex A1 for neutral salt spray performance requirements for zinc, zinc alloy and cadmium coatings. Threaded Tip, awtm 0. The external thread damage is also minimized in comparison astmm barrel-plating due to the absence of tumbling.
The test plan should be designed based upon the speci? This standard does not purport to address all of the safety concerns, if any, associated with its use. All information presented is for general reference and does not represent a professional opinion nor the policy of an author’s employer. The cascading action randomly exposes the surface of each individual piece to the process electrodes while also maintaining electrical continuity between all of the parts.
However, if not designated, signi? Toby — Thanks for boiling it down for me.
High current densities increase hydrogen charging. Your comments are invited either for revision of this standard or for additional standards ff1941 should be addressed to ASTM International Headquarters.
Which finish to choose? Refer to Appendix X1. From beautiful Pine Atm New Jersey: The values given in parentheses are for information only. When such areas are subject to minimum thickness requirements, the purchaser and the manufacturer shall recognize the necessity for either thicker deposits on other areas or special racking.
The local coating thickness on a part is a result of the electrical current density at that location. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement astn such rights, are entirely their own responsibility.
ASTM F – Portland Bolt
This can 6 damage the external threads of fasteners. My follow up question would be, if the fasteners are coated with trivalent chromite adding the designation “T”why do the salt spray hours in the ASTM spec differ between any color chromate designation? The electrical continuity is maintained between the parts by the rack itself. Although this risk can be managed by selecting raw materials suitable for the application of electrodeposited coatings and by using modern methods of surface treatment and post heat-treatment bakingthe risk of hydrogen embrittlement cannot be completely eliminated.
NOTE 2—With proper care many steel fasteners can be plated without baking by correlating process conditions to the susceptibility of the fastener material to hydrogen embrittlement, and by applying adequate process control procedures, such as those outlined in Appendix X4.
r1941 ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. I am getting really confused in the finishing section. Special processing is normally required for bolts with a ratio greater than 10 in order to minimize the extremity-to-center thickness ratio. It zstm coating thickness, supplementary hexavalent chromate or non-hexavalent conversion coatings, corrosion resistance, precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for high-strength and surface-hardened fasteners.
The other dimensional characteristics shall be as speci? Ordering Information for Electroplating 5. If heavier coatings are required allowance for the deposit buildup must be made during the manufacture of fasteners.
ASTM / ASME spec F for Zinc Plating Which finish to choose?
One of these should meet your needs. The effect of thread damage is worse on heavy? On an externally threaded fastener this occurs at the threaded tip. With normal methods for depositing metallic coatings from aqueous solutions, there is a risk of delayed failure due to hydrogen embrittlement for case hardened fasteners and fasteners having a hardness 40 HRC or above. Corrosion resistance and embrittlement of coatings shall be determined by performing mechanical tests.
A number in parentheses indicates the year of last reapproval. The external thread allowance may thus be used to accommodate the coating thickness on threaded fasteners, provided the maximum coating thickness is no more than 1?
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. Diameter Din.
As the barrel is moved through the process steps, it is also rotated such that the individual items are constantly cascading over one another. It should be noted that modi?
Refer to Appendix X3 for further information on effects of coating on pitch diameter, allowances and tolerances for external and internal threads. In some of the process steps, notably the electrocleaning and electroplating steps, an electric current is applied to the group of items.
My company uses fasteners in the most simple sense–like the kind of fasteners you buy in the bulk bin at the local hardware store. Eight hours is considered a typical example of baking duration.
Originally published as F —