This standard is issued under the fixed designation F ; the 1 This specification is under the jurisdiction of ASTM Committee F16 on. ASTM: F – Standard Specification for Chromium/Zinc Corrosion Protective Coatings for Fasteners. 1. Scope This specification covers the basic. ASTM F/FM Standard Specification for Zinc/Aluminum Corrosion Protective Coatings for Fasteners. standard by ASTM.
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This fastener is made from weathering axtm which is inherently corrosion resistant. It is required that the bolt and nut are coated by the same process, but the washer can be an alternate coating.
Alkaline cleaning or vapor degreasing is required along with shot blasting to remove rust or scale. F Grade 3, commonly known as Dacromet. Serge- We have very little experience with Dacromet coating. We also see no issues with pre-tensioning.
High Strength Bolts Coatings
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. The coating process does not induce the possibility of internal hydrogen embrittlement provided that the fasteners have not been cleaned or pre-treated with an acid or phosphate. Leave this field empty. So what are the alternatives to provide corrosion resistance for A structural bolts? But there are some doubts. Historical Version s – view previous versions of standard.
Leave a Reply Cancel reply Your email address will not be published. Your first question, is it appropriate to specify ASTM F Grade 3would be best answered by an engineer familiar with the coating and the application. Link to Active This link will always route asfm the current Active version of the standard. F11336 on the amount of corrosive forces at work in the application, F may be sufficient, but it may not.
Hot-dip galvanized hex nuts are therefore tapped oversize to accommodate the thick coating, whereas F specifically states that the thread fit shall not be adversely affected.
Consulting a structural engineer involved on the project is always the best solution. The bolts f11136 nuts are already coated with Dacromet and the proposal is to coat the DTI washers with Magni A coatings engineer may choose to allow an exception in some cases, but ASTM will not officially sanction any coatings that are not approved by the F16 committee.
Protective Coatings ASTM recommends that if a protective coating is required for A bolts, one of two approved coatings is recommended. The coatings are classified into six grades Grades 1 to 6 according to the required minimum basecoat thickness, and when tested, shall conform accordingly to appearance, adhesion, corrosion resistance, blister, thread fit, and hydrogen embrittlement requirements. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application.
They were used to in flange type splices of two tubular monopole sections. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
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 tightening torque may vary from plain finish or other coatings, but the bolt should still function the same. Parham- We cannot make specific recommendations, but I ast say that painting A bolts is quite common. Jovito- We would be happy to quote your specific bolting needs if you want to send us a list of the bolts you are looking for.
If so, did the tension will be higher? No metric equivalents are presented in this specification.
I am using A grade BC and need a smooth finish with minimal irregularities. Is fluorocarbon coating acceptable to A bolts for corrosion prevention? Hello, We have specified A Dracomet coated bolts g1136 a telecommunications monopole in Canada. Due to hydrogen embrittlement concerns ASTM recommends against hot-dip galvanizingmechanical deposition, or electroplating with zinc or other metallic coatings on high strength bolts ultimate tensile strengths that exceed ksi.
Since the Dacromet and Magni will be in contact with one another, Are they compatible with one another? The basecoat can contain chrome C or be non-chrome NC. Your email address will not be published.
I suppose they are similar to painting. The corrosion protection offered by F in those cases would be superior qstm nothing at all. I do not have any friction coefficient information on Magniso I do not know how much the torque will be affected. However, these fasteners are not as readily available in the marketplace as A Type 1. As for the thickness of both coatings, F grade 3 specified a coating thickness of 0.
Is the coating that fragile? Since we are using A astmm in our structure, we satm to propose a replacement.
High Strength Bolts Coatings – Portland Bolt
What corrosion-resistant coatings are available for high-strength over ksi bolts? Although hot-dip galvanize provides high aetm level barrier protection 2 mils for substrates, it is not approved for use on high strength bolts because hot dip galvanize is susceptible of hydrogen embrittlement and cracking of fasteners that can result out in the field.
Work Item s – proposed revisions of this standard.
Since the bolts are pre-tensioned, will there be any issues with Magni with regard to pre-tensioning i. One year after installation the bolts are rusting.