螺紋節距與 TPI 計算器
Convert metric thread pitch to threads per inch (TPI), calculate thread lead and compare single-start with multi-start threads.
結果是根據上述輸入參數計算得出的；範例數值僅供說明之用，並非針對特定工具的速度／進給建議。.
公式與計算方法
Pitch (mm) = 25.4 / TPI; lead = pitch × number of starts.
Thread pitch is the spacing between adjacent thread crests. Threads per inch counts the number of thread pitches in 25.4 mm. On a single-start thread lead equals pitch; on multi-start threads lead is pitch multiplied by the number of starts. Lead determines axial movement per workpiece revolution.
重要假設與限制
This calculator covers pitch and lead relationships only. It does not determine thread tolerance class, flank form, pitch diameter, fit or permitted thread profile.
常見問題
Is pitch equal to lead?
Only for a single-start thread.
What is 1.5 mm pitch in TPI?
25.4 ÷ 1.5 = approximately 16.93 TPI; it is not necessarily a standard UNC or UNF size.
技術參考資料： Haas — 攻牙與切槽公式. 針對 ONMY 的計算是獨立進行的；來源連結並不代表任何背書。.
