絲錐底孔 規格表
2種規格資料
攻絲鑽孔表列出公制螺紋攻絲前需要的底孔尺寸。基本公式為底孔=公稱直徑−螺距，但需根據材料硬度和絲錐類型微調。底孔過小會折斷絲錐，過大則有效螺紋不足。
常見問題 (FAQ)
What is the difference between coarse thread and fine thread?
Coarse thread (e.g., M10×1.5) is for general fastening with a larger pitch. Fine thread (e.g., M10×1.25) has a smaller pitch, better for fine adjustment, vibration resistance, and thin walls.
How do you calculate tap drill diameter?
Drill size = nominal diameter − pitch. Example: M10×1.5 → drill 8.5mm; fine thread M10×1.25 → drill 8.8mm. Refer to spec tables for exact values; this formula works as a quick field estimate.