I need to chase threads on shaft. Anyone know diameter/pitch for die ?
In a parts book, look up the factory nut…It will usually give the size and pitch especially if it’s metric…
US , 3/4 SAE, 20tpi
I’ll offer a suggestion that isn’t for the fastidious or faint of heart. Try a file. Not a mill cut one, but a small v pattern maker’s file (also referred to as rifflers or needle files ) to dress the damaged threads. Depending on how badly and where the damage is you might save a lot of time, money and potentially making things worst if the die doesn’t start correctly. If the threads have been flattened or nicked along the side of the shaft just file the damaged portion along the existing groove until the thread is clear. If the end of the shaft is mushroomed you might need a bigger file to reshape it then use the small file to restore the first thread. Work slowly and check often with the nut. This technique has saved me a lot of trouble. Try finding the die for a Bultaco sprocket shaft on short notice.