Phosphate coating is a chemical conversion process in which the fastener surface reacts with a phosphoric acid solution to form an integral, crystalline phosphate layer. Asia Bolts Industries applies phosphate coatings per ASTM F1137, which covers both zinc phosphate and manganese phosphate grades for threaded fasteners.<\/p>\n
Unlike electroplated coatings, phosphate does not add significant dimensional build-up \u2014 making it ideal for precision-threaded fasteners where tight tolerance control is critical. The coating is typically 2\u201325 \u00b5m thick and is porous, which allows it to retain supplementary rust-preventive oils (oiled finish) for enhanced protection, or to serve as a paint\/primer adhesion promoter.<\/p>\n
Phosphate Grade Options:<\/p>\n
\u2022 Zinc Phosphate: Fine-grained, excellent paint adhesion, lower friction \u2014 preferred for bolts requiring torque-tension control<\/p>\n
\u2022 Manganese Phosphate: Coarser grain, high oil retention, better wear resistance \u2014 preferred for heavy-duty mechanical fasteners<\/p>\n
Grade Classification per ASTM F1137:<\/p>\n
\u2022 Grade 1: Zinc phosphate without supplemental oil<\/p>\n
\u2022 Grade 2: Zinc phosphate with supplemental oil<\/p>\n
\u2022 Grade 3: Manganese phosphate without supplemental oil<\/p>\n
\u2022 Grade 4: Manganese phosphate with supplemental oil<\/p>\n
\u2022 Grade 5: Zinc phosphate with dry film lubricant<\/p>\n
Common applications include automotive fasteners, flange bolts, heavy structural bolts, and bolts used in flanged joint assemblies where controlled torque-tension is required. All phosphate coated fasteners from Asia Bolts are supplied with coating type, weight, and oil supplement documentation.<\/p>","protected":false},"excerpt":{"rendered":"
Phosphate coating (phosphatizing) applied per ASTM F1137 to carbon steel fasteners. Provides a crystalline conversion coating that enhances paint adhesion, reduces friction during assembly, and offers moderate corrosion resistance. Available in zinc phosphate and manganese phosphate grades, with or without oil supplementary treatment.<\/p>\n
Standard<\/strong><\/td>\n| ASTM F1137<\/td>\n<\/tr>\n | Base Material<\/strong><\/td>\n | Carbon Steel, Alloy Steel<\/td>\n<\/tr>\n | Salt Spray<\/strong><\/td>\n | 24\u201396 hours (oiled finish)<\/td>\n<\/tr>\n | Thickness<\/strong><\/td>\n | 2\u201325 \u00b5m<\/td>\n<\/tr>\n | Applications<\/strong><\/td>\n | Automotive, flanged joints, torque-critical assemblies, paint adhesion base<\/td>\n<\/tr>\n<\/tbody>\n<\/table>","protected":false},"featured_media":3663,"template":"","meta":{"_kadence_starter_templates_imported_post":false},"product_brand":[],"product_cat":[212],"product_tag":[220],"class_list":["post-3652","product","type-product","status-publish","has-post-thumbnail","product_cat-fastener-coatings-surface-treatments","product_tag-phosphate-coating","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product\/3652","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media\/3663"}],"wp:attachment":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media?parent=3652"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_brand?post=3652"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_cat?post=3652"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_tag?post=3652"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} | |