Clamp two pieces of ally stock together with a shim between them, drill a handful of half-inch through holes along the line and tap for the stud thread. Load the bottom block into mill vice, load up your studs with a stop to align the and g-clamp the top half on top. Threads will stop the studs from slipping and you can cut them 5 at a time. When you've done with the 1/2" re-drill for the larger ones and repeat.
Peter - novice home machinist, modern motorcycle enthusiast.
Denford Viceroy 280 Synchro (11 x 24)
Herbert 0V adapted to R8 by 'Sir John'.