Are UNC and BSW threads interchangeable?

If you are struggling to find either a BSW thread (British Standard Whitworth) or an UNC thread (Unified National Coarse), it is useful to know that in almost all cases the two threads are interchangeable in practical terms except for 1/2" where the thread pitch is different: BSW = 12 tpi and UNC = 13 tpi

UNC threads have a 60 degree thread angle
BSW threads have a 55 degree thread angle

Click here to view our comprehensive thread pitch chart