Metric coarse thread is the default choice in many industrial fastener orders. In the workshop, we see it every day on bolts, screws, nuts, studs, anchors, and threaded rods. It is easy to source, easy to assemble, and usually more tolerant of dirt or minor handling damage than fine thread.<\/p>\n\n\n\n
Still, buyers should not write only \u201cM12 bolt\u201d on an RFQ. The pitch must be confirmed, especially when parts must match existing nuts, tapped holes, or imported equipment.<\/p>\n\n\n\n
Metric thread is described by diameter and pitch. For example, M12 \u00d7 1.75<\/strong> means a 12 mm nominal diameter and a 1.75 mm pitch.<\/p>\n\n\n\n When the pitch is not written, many suppliers assume standard coarse pitch. That works for common stock items, but it can create mistakes when the mating part uses fine thread.<\/p>\n\n\n\n For regular orders, buyers can review common standard fasteners<\/a> or bolt products<\/a> before confirming the RFQ.<\/p>\n\n\n\n This chart is useful for quoting and quick checking, but final production should still follow the required DIN, ISO, ASTM, EN, or drawing standard.<\/p>\n\n\n\n Coarse thread is usually preferred for:<\/p>\n\n\n\n Fine thread may be used when the design needs finer adjustment, thinner wall engagement, or specific OEM requirements. It should be clearly stated on the drawing or RFQ.<\/p>\n\n\n\n The most common mistake is mixing coarse and fine thread parts in one order. M12 \u00d7 1.75 and M12 \u00d7 1.5 look close, but they will not assemble correctly.<\/p>\n\n\n\n Also check coating. Hot-dip galvanizing, zinc flake, and PTFE coating can affect thread fit. For coated products, review various coated fasteners<\/a> and confirm nut assembly after finishing.<\/p>\n\n\n\n Before ordering metric coarse thread fasteners, provide:<\/p>\n\n\n\nCommon Metric Coarse Thread Chart<\/h2>\n\n\n\n
Metric Size<\/th> Standard Coarse Pitch<\/th> Common Fastener Use<\/th><\/tr><\/thead> M3<\/td> 0.5 mm<\/td> Small screws, light assemblies<\/td><\/tr> M4<\/td> 0.7 mm<\/td> Electrical parts, brackets<\/td><\/tr> M5<\/td> 0.8 mm<\/td> Machine screws, small equipment<\/td><\/tr> M6<\/td> 1.0 mm<\/td> General machinery<\/td><\/tr> M8<\/td> 1.25 mm<\/td> Brackets, frames, equipment<\/td><\/tr> M10<\/td> 1.5 mm<\/td> Machinery and structural support<\/td><\/tr> M12<\/td> 1.75 mm<\/td> Equipment bases, steel parts<\/td><\/tr> M16<\/td> 2.0 mm<\/td> Heavy machinery, construction<\/td><\/tr> M20<\/td> 2.5 mm<\/td> Steel structures, large assemblies<\/td><\/tr> M24<\/td> 3.0 mm<\/td> Heavy-duty bolted joints<\/td><\/tr> M30<\/td> 3.5 mm<\/td> Large equipment and foundations<\/td><\/tr> M36<\/td> 4.0 mm<\/td> Anchors, structural connections<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n Coarse Thread vs Fine Thread<\/h2>\n\n\n\n
When Coarse Thread Works Best<\/h3>\n\n\n\n
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Common Buyer Mistakes<\/h2>\n\n\n\n
RFQ Checklist<\/h2>\n\n\n\n
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