丝锥底孔 规格表
2种规格数据
攻丝钻孔表列出公制螺纹(标准和细牙)攻丝前需要的底孔尺寸。基本公式为底孔=公称直径−螺距，但需根据材料硬度和丝锥类型微调。底孔过小会折断丝锥，过大则有效螺纹不足。
常见问题 (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.