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.
|Published (Last):||2 May 2009|
|PDF File Size:||10.80 Mb|
|ePub File Size:||13.35 Mb|
|Price:||Free* [*Free Regsitration Required]|
Leave a Reply Cancel reply Your email address will not be published.
High Strength Bolts Coatings
This abstract is a brief summary of the referenced standard. That said, I do not know much about fluorocarbon coatings and how they are applied. F Grade 3, commonly known as Dacromet. This fastener is made from weathering steel which is inherently corrosion resistant. Normally where I see F specified is in applications with higher strength fasteners that cannot be hot-dip galvanized, such as ASTM A heavy hex bolts. 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, atsm fit, and hydrogen f113 requirements.
Your email address will not be published. Although hot-dip galvanize provides high thickness 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.
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. Hello, We have specified A Dracomet coated bolts for a telecommunications monopole in Canada.
High Strength Bolts Coatings – Portland Bolt
If so, did the tension will be higher? The tightening torque may vary from plain finish or other coatings, but the bolt should still function the same. What corrosion-resistant coatings are available for high-strength over ksi bolts? Alkaline cleaning or vapor degreasing is required along with shot blasting to remove rust or scale.
Leave this field empty. It is the responsibility of the user of this standard to establish appropriate safety and health practices and f113 the applicability of regulatory limitations prior to use.
Since the Dacromet and Magni will be in contact with one another, Are they compatible with one another? I am using A grade BC and need a smooth finish with minimal irregularities.
I suppose they are similar to painting.
Serge- We have very little experience with Dacromet coating. We are not sure how fragile the coating is during installation. 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.
Depending on the amount of corrosive forces at work in the application, F may be sufficient, but it may not. Since we are using A bolts in our structure, we have to propose a replacement. 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.
ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete ast up to date. Protective Coatings ASTM recommends that if a protective coating is required for A bolts, one of two approved coatings is recommended.
The bolts and nuts are already coated with Dacromet and the proposal is to coat the DTI washers with Magni Work Item s – proposed revisions of this standard. Referenced Documents purchase separately Ast, documents listed below are referenced within the subject standard but are not provided as part of the standard. Is fluorocarbon coating acceptable to A bolts for corrosion prevention? 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.
They were used to in flange type splices of two tubular monopole sections.
So what are the alternatives to provide corrosion resistance for A structural bolts?