These Hexagonal nuts are of the correct type as fitted to all magnesium crankcased SOHC and early DOHC racing engines and are made as per the original design - i.e. 47mm Across Flats, for fitment to the magnesium crankcase bigends (see item 0072) .
Price is each.
This larger diameter nut allowed more 'holding area' than the small International nuts, probably because the Manx pins had less depth. - Price is 'per nut' -
If you are not sure what type of nuts your engine should be fitted with : Earlier Manx 500CC Bigends (all SOHC\DOHC magnesium cased pre-featerhbed engines and earlier Featherbed engines) used large 47mm AF Hex Nuts.
However, if you have a pre-war SOHC M40 350cc model (i.e. pre-war 350cc magnesium crankcase Manx model) - please check with us before ordering - we have found in the past it is most likely that model will be fitted with the standard Manx 500 type Bigend, but often be fitted with the smaller 42mm nuts - we normally keep a couple of these in stock, same price as the 47mm nuts)
Later shortstroke DOHC engines used castellated nuts (but either type can be used - providing you have the correct spanner for each). I can supply both types. If you are not sure if your flywheels should be using Hex nuts - look for the 'Mickey Mouse ear' cutaways, for grub screws (see 2nd photograph), which signify it was fitted with the bigger type Hex nuts. Wherever possible, if the engine was fitted with these larger nuts, you should try and refit them, as they provide a larger surface area than castellated or International nuts.