We may be familiar with the myriad of bolts and nuts in their various sizes when we enter a hardware store. But most of these hardwares come with screw threads of standard pitches. When you step into Hup Yick, a manufacturer of hardware, you realise that the variety of the ubiquitous bolt can be even greater than you thought !
Die heads that hold sets of chasers adjust to a range of diameters and threading pitches. In the case of automotive parts, it is common to  nd double-pitched bolts such as the studs used
in the Austin A60 Cambridge sedan for the securing of a petrol pump gasket to the engine block. Redesigned as a pendant, the dual-threads imbue a haptic quality to the stud.
The  ne thread of 0.75 (36 threads per inch) also meant we could make use of obsolete parts, such as the 0.75-threaded hexagonal nut!
 
brass double-pitched stud