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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NOTE 1—Fasteners with a speci? The electrodeposited coating shall cover all surfaces and shall meet the following requirements: Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.
Which finish to choose? Toby — Thanks for boiling it down for me. From beautiful Pine Beach New Jersey: It also highlights the differences between barrel and rack plating and makes recommendations as to the applicability of each process.
A number in parentheses indicates the year of last reapproval. Refer to Annex A1 for neutral salt spray performance requirements for zinc, zinc alloy and cadmium coatings. Measuring coating thickness on the threaded portion of a fastener is possible but impractical for in-process quality control veri? Special processing is normally required for bolts with a ratio greater than 10 in order to minimize the extremity-to-center thickness ratio.
Refer to Appendix X3 for further information on effects of coating on pitch diameter, allowances and tolerances for external and internal threads.
Test Method F is a recognized veri? That standard should be consulted for more detailed information. In this process, quantities of an item are placed within a containment vessel, called a barrel. Corrosion resistance and embrittlement of coatings shall be determined by performing mechanical tests.
Is there an acceptable way to demonstrate equivalence? Screw threads that are speci? Ordering Information for Electroplating 5.
ASTM / ASME spec F1941 for Zinc Plating … Which finish to choose?
Long screws and bolts have a length-to-diameter ratio greater than 5 but less than A superscript epsilon e indicates an editorial change since the last revision or reapproval. Thick or thin local thickness in a location other than a signi? Work Item s – proposed revisions of this standard. This applies to the qstm cases: However the following restrictions apply: In this process, quantities of an item are placed on a support, called a rack.
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. The chromate finish letter E designates a black color.
ASTM F – Portland Bolt
As the barrel is moved through the process steps, it is also rotated such that the individual items are constantly cascading over one another.
Slight discoloration that results from baking, drying, or electrode contact during rack-plating, or all of these, as well as slight staining that results from rinsing shall not be cause for rejection. Diameter Din. 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.
The test plan should be designed based upon the speci? December 9, Q. My research is leading me to believe that ASTM F M both inch and metric are the two standards I need; but even those have over grades listed! It’s not possible to diagnose a finishing problem or the hazards of an operation via these pages. 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.
The coating material, coating thickness, chromate finish, and trivalent chromite finish shall be selected and designated. Therefore, the application of a metallic coating by electrodeposition is not recommended for such fasteners. 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.
Thank you for your assistance. Changing the last letter to a B means that the chromate is blue-bright transparent with a bluish tinge and slight Iridescence or C means that it is yellow yellow iridescent.
High current densities increase hydrogen charging. Link to Active This link will always route to the current Active version of the standard.
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. To secure uniformity of results, samples shall be aged at room temperature for 24 h before being subjected to the salt spray test.
Threaded Tip, 3 0. 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. This standard does not purport to address all of the safety concerns, if any, associated with its use. In some of the process steps, notably the electrocleaning and electroplating steps, an electric current is applied to the group of items.
If heavier coatings are required allowance for the deposit buildup must be made during the manufacture of fasteners. This standard does not purport to address all of the safety concerns, if any, associated with its use. It also highlights the differences between barrel and rack plating and makes recommendations as to the applicability of each process.
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. It specifies coating thickness, supplementary hexavalent chromate or trivalent chromite finishes, corrosion resistance, precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for high-strength and surface-hardened fasteners.