Mechanical galvanizing is a cold, mechanical process used to apply zinc coatings to fasteners without heat or electrochemical action. The fasteners are tumbled in a rotating barrel with glass beads, zinc powder, water, and chemical promoters. The glass beads impact-peen the zinc powder onto the fastener surface, producing a coating with performance characteristics comparable to hot-dip galvanizing but without thermal or hydrogen embrittlement risks.<\/p>\n
Asia Bolts Industries applies mechanical galvanizing per ASTM B695, which covers classes from Class 25 (25 \u00b5m minimum) to Class 110 (110 \u00b5m minimum), with corresponding coating weight and corrosion performance requirements.<\/p>\n
Why Mechanical Galvanizing Over HDG for High-Strength Fasteners:<\/p>\n
\u2022 Hot-dip galvanizing exposes fasteners to 450\u00b0C, which can alter the mechanical properties of high-strength alloy steel bolts<\/p>\n
\u2022 Electroplating introduces hydrogen into the steel lattice (hydrogen embrittlement risk) \u2014 requiring subsequent baking; mechanical galvanizing does not<\/p>\n
\u2022 For ASTM A490, Grade 10.9, and SAE Grade 8 fasteners, mechanical galvanizing is the preferred zinc coating method<\/p>\n
ASTM B695 Class Options:<\/p>\n
\u2022 Class 25: 25 \u00b5m minimum \u2014 moderate protection<\/p>\n
\u2022 Class 40: 40 \u00b5m minimum \u2014 equivalent to light HDG<\/p>\n
\u2022 Class 55: 55 \u00b5m minimum \u2014 equivalent to standard HDG (most common for structural bolts)<\/p>\n
\u2022 Class 80 \/ 110: Heavy-duty offshore and marine applications<\/p>\n
Supplementary chromate passivation is available to improve initial corrosion resistance and aesthetics.<\/p>\n
Applications include high-strength structural bolts (ASTM A490, SAE Grade 8), flange bolts for oil & gas piping systems, heavy anchor bolt assemblies, and all applications where hydrogen embrittlement is a specified design concern.<\/p>","protected":false},"excerpt":{"rendered":"
Mechanical galvanizing per ASTM B695 \u2014 a cold process alternative to hot-dip galvanizing that eliminates hydrogen embrittlement risk. Zinc powder is impacted onto the fastener surface in a rotating barrel with glass beads and promoter chemicals. Preferred for high-strength fasteners (Grade 8.8, 10.9, ASTM A490) where thermal processes are not suitable.<\/p>","protected":false},"featured_media":3666,"template":"","meta":{"_kadence_starter_templates_imported_post":false},"product_brand":[],"product_cat":[212],"product_tag":[],"class_list":["post-3653","product","type-product","status-publish","has-post-thumbnail","product_cat-fastener-coatings-surface-treatments","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product\/3653","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\/3666"}],"wp:attachment":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media?parent=3653"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_brand?post=3653"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_cat?post=3653"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_tag?post=3653"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}