A. ASTM F is for inch-based fasteners and ASTM FM is for metric fasteners, although the designations are identical between the two. The fastener industry should be made aware of an important recent development in the realm of. ASTM fastener standard specifications. ASTM F/. ASTM F/FM: Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric.
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This standard does not purport to address all of the safety concerns, if any, associated with its use. This standard does not purport to address all of ast safety concerns, if any, associated with its use.
ASTM International takes no position respecting the validity of any patent rights asserted in ff1941m with any item mentioned in this standard. It should be noted that modi? F — 00 Standard Speci? This abstract is a brief summary of the referenced standard. All I want is a single spec to call out, to get the basic zinc-electroplated fastener.
However the following restrictions apply: 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. 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.
It also highlights the differences between barrel and rack plating and makes recommendations as to the applicability of each process. 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.
This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded fasteners with metric screw threads.
Current edition approved Jan. I am getting really confused in the finishing section. 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?
Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
The coating material, coating thickness, chromate finish, and trivalent chromite finish shall be selected and designated. Eight hours is considered a typical example of baking duration.
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 other dimensional characteristics shall be as speci? 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.
For example, rather than specifying: Your comments are invited either for revision of this standard or for additional ashm and should be addressed to ASTM International Headquarters. The external thread damage is also minimized in comparison t1941m barrel-plating due to the absence of tumbling. It is my understanding that the darker colors are a naturally occurring process due to the hexavalent chromium and provide greater corrosion resistance. It also highlights the differences between barrel and rack plating and makes recommendations as to the applicability of each process.
To secure uniformity of results, samples f1941k be aged at room temperature for 24 h before being subjected to the salt spray test. The appearance of corrosion products visible to the unaided eye at normal reading distance shall be cause for rejection, except when present at the edges of the tested fasteners. Isn’t the color achieved by adding a dye and the corrosive resistance achieved through a sealer r1941m thicker chromate? One of these should meet your needs. In contrast, the center or recesses such as the bottom of the threads, which are the low current density areas, receive the lowest coating thickness.
ASTM F – Portland Bolt
The testing frequency should initially establish and subsequently verify over time, the ability of a process to produce parts that do not have the potential for hydrogen embrittlement. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
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 satm. NOTE 1—Fasteners with a speci? It specifies 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.
Periodic inspections should be conducted according to a speci? The local coating thickness on a part is a result of the electrical current density at that location. Screw threads that are speci? If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.
This phenomenon is accentuated with increasing length and decreasing diameter of the screw or bolt.