មានប៊ូឡុងគោលឆកោនចំនួន 4 ដែលប្រើជាទូទៅគឺ 1. GB/T 5780-2016 "Hexagon Head Bolts Class C" 2. GB/T 5781-2016 "bolts ក្បាល hexagon with full thread C grade" 3. GB/T 5782-2016" Hexagon Head Bolts" 4. GB/T 5783-2016 "Hexagon head bolts with full thread" ...
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