ET: Engine (Twin) Drain Plugs BSW or BSP?

[Rob H]

Can anyone tell me if the thread for the gearbox and crankcase drain plugs are tapered or normal thread?

 

[Michael Vane-Hunt]

BSP

 

[Robert Watson]

BSP Straight thread 19TPI

Know Thy Beast has all the threads listed in appendix 11 and is a must have book for a Vincent owner