This item is for a pair of the correct, original Norton pattern, bolts and extra heavy washers that were fitted to the bottom of plunger spindles to Norton Gargengate type (plunger) frames. The set consists of 2 CNC manufactured bolts, 2 washers in stainless steel and are identical in pattern to originals.
Although these bolts look similar to many other Norton bolts of this period - they were actually specific to the Norton Gargengate frame (the bolts are original Norton Part Number B4/672) and had differences to other Norton bolts of similar appearance. Likewise, the washers were also designed specifically for the purpose - and are far thicker and wider than other similar bore washers - both patterns are now quite rare to find in good condition and ours are identical in pattern - other than being manufactured in stainless steel - so they will not rust and look very pretty.
The bolt head was actually wider than other similar thread size bolts (7/16" BSC Cycle, which is a widely used thread on Norton singles), and the washer extra thick - so that it was possible to exert a strong force with a 3/8 Whit spanner, which would ensure that the the taper of the plunger spindle would be fully pulled into the corresponding taper of the bottom frame plunger casting. It also helped ensure that the nut and washer was less susceptable to come loose - particularly important as many plunger mechanism's tend to lock up with rust and corrosion over the years. Finally, this design with big bolt head probably helped in the removal of the spindle, if seized, as the bolt could be loosened a couple of turns and then the bolt head hit with a mallet to help loosen the taper fit.
It can therefore be seen that the design of this bolt and washer (or heavy duty spacer as it might more correctly be termed) have a more elaborate design than is at first obvious - and is therefore important to fit those original design if possible. It is not unusual to see incorrect bolts and washers fitted to original Gardengate models, with the heads chewed and if thinner washers fitted - those badly bent! As a final desgin point on original bolts, they also have a small unthreaded shoulder on the thread end of the bolt - not sure exactly the purpose of this - but assume these may locate with an internal shoulder or end of thread in the spindle.
As can be seen in the accompanyning photographs, one picture shows our bolt and washer fitted to an original (Manx) Gardengate frame (as they are fitted at the bottom of the plungers - much of our pretty head is not visible! In another photograph is an original Norton 'New Old Stock' bolt and washer, from which our designs were copied.
Final point - although shown fitted to a Manx frame, these bolts were fitted to all Norton Gardengate frames from 1939 through to the end of the Gardengate plunger frames use in the early 1950's. Although I often offer a 'reduced weight/wasted' version of bolts for competition models, I do not believe the Manx versions were any different to the road models . . . and because of the design described above - would not advise trying to lighten this bolt
Set consists of 2 bolts, 2 extra thick washers in stainless steel, with original Norton bolt head dome design (and lighthly linished and polished to remove any burrs).