These spindles have been CNC machined in the UK from EN16T. The hexagon on the lower front spindle is not load bearing so is made from stainless steel and then screwed onto the spindle.
 
This spindle set will fit Norton girder forks manufactured between 1932 and 1939 with parallel legs as fitted to the Model 30 and 40 Internationals. All other models had splayed fork legs so the bottom spindles were longer. We sell these spindles as well so please see our other parts. 
 
Part numbers from the 1933/34 parts book and overall lengths are as shown below so please check they will fit your bike before purchasing. From left to right: 
2 off part number 3179 'Front Fork Top Spindle'. 9'' overall length.
1 off part number 3182 'Front Fork Bottom Spindle, Rear'. 9.5'' overall length.
1 off part number 3183 'Front Fork Bottom Spindle, Front' with hexagon and thread for damper knob. 10'' overall length.
 
All 4 spindles are 1/2'' diameter.