This is the E3227 0.5" x 20tpi nut that is used on the front downtube engine bolt on Model 30/40 and M30/M40, CS1/CSJ models.  The nut follows original Norton profile - i.e. being a reduced sized Hex and deeper in depth than other commercial 0.5" nuts. The nut is CNC manufactured by us in non rusting stainless steel, with faces linished.

As there were so many variations of Norton SOHC engine bolts/nuts, the table below shows the spec of these nuts and their most normal application :

Bolt Table Legend and Useful Information: 

AF = "Across Flats', i.e the diamter in inches of hex bar between the two opposite flats - this is the diameter the spanner gap needs to be - we use the correct 'British Standard' bar, as fitted to all Norton single cylinder motorcycles originally, to fit BSW spanners. 

UH = 'Under Head' Bolt Length, i.e. when measuring the length of the bolt shaft - dimensions are taken from the distance at the base of the hex head to the end of the threaded shaft.  It does not take into account the height of the hex head, or the slightly rounded chamfer at the end of the threaded shaft, which are additional.  (Please bear in mind length is nominal - there may  be 1 or 2 mm variation because of batch variation). 

Therefore - when comparing the length shown in the table above to your own engine, you need to take into account the width of the engine casting, engine plates and the height of the nut.  Also, any brackets that you may fit under the bolt head - I have tried to base the length of bolts on not having additional brackets unless I know they were standard (the nuts are normally extra width though and can be narrowed slightly if necessary, or one of the washers omitted

Remember that in some cases, bolts were fitted where there may have only been an engine plate on one side - i.e for the rear of the engine on most SOHC engines, the bolt immediately above the magneto platform has an engine plate only on one side, while the bolt under the magneto has an engine plate on both sides - which is why I make 2 versions of these bolts.  Norton did not bother originally, fitting the same length bolt to both)

Reduced Hex Nuts : for many of the bolts and nuts fitted to Norton motorcycles, the AF (Across Flats) diameter was less than normal commerically available nuts for a given bolt shaft size - the rationale for this was that there was not much room around complex castings, therefore you needed to be able to get access with a smaller spanner.  To allow for this, many of the engine bolts and nuts with these 'reduced head size to shaft diameter' nuts also had a deeper depth of hex as well, to provide as much spanner to hex contact as normal bolts - reducing the chance of 'rounding' the hex when applying a lot of pressure with spanners and providing as much thread on the nuts as possible - but important with the pressure required of engine bolts. 

The nuts shown here replicate the Norton nuts and are deeper than commercially available nuts.  In some cases - i.e. if you are fitting thicker washers or ancillary brackets, you may find the nut is deeper than the bolt allows.  In this case the easiest way I have found to reduce the depth of a nut (if a lathe is not available), is to hold the nut in a ring spanner and place its lower unchamfered face carefully against a linisher (make sure you use suitable safety glasses and gloves when doing this) 

Thread Type:  Engine Bolts on Norton engines tended to come in most of the standard British Whitworth diameters, with the following common thread types, where TPI means 'threads per inch':  1/4" (shaft diameter) x 26 tpi (Threads per inch), 5/16" x 26 tpi, 3/8" x 26 tpi, 7/16" x 20 tpi, 1/2" x 20 tpi.

Most thread profiles were originally BSC (British Standard Cycle), but please note that 7/16" x 20tpi is also a UNF standard thread size and none of the tooling manufacturers will now make the BSC profile tooling - therefore we manufacture this size nut/bolt in UNF profile.  These nuts may fit on original bolts, but can be slightly tighter.

Overall, these nuts are high quality, CNC machine finished to look just as the original Norton items, but in non rusting stainless steel, with original Norton dimensions and profiles.   We linish the hex faces on the bolt heads to ensure crisp finishes and we hope you find the will give that finishing touch to any restoration - or just clean up the look of your oily rag, ride to work Norton!

This is the E3238 7/16" x 20 tpi engine nut as fitted to many Norton engine bolts.  It has the correct 'reduced head' and greater depth than other commercially available nuts of this thread/size - and is CNC made specially by us for fitting to Norton engine bolts, but in stainless steel.

Note: the thread for this nut is 7/16" x 20tpi UNF profile.  This is almost identical to the original 7/16" x 20tpi BSC thread, but with a fractionally different tooth profile.  I recommend if using these nuts with original bolts you buy one nut and try first.  If bought with our corresponding bolts they are a matching pair.  Unfortunately original BSC taps in this size are no longer available.

Bolt Table Legend and Useful Information: 

AF = "Across Flats', i.e the diamter in inches of hex bar between the two opposite flats - this is the diameter the spanner gap needs to be - we use the correct 'British Standard' bar, as fitted to all Norton single cylinder motorcycles originally, to fit BSW spanners. 

UH = 'Under Head' Bolt Length, i.e. when measuring the length of the bolt shaft - dimensions are taken from the distance at the base of the hex head to the end of the threaded shaft.  It does not take into account the height of the hex head, or the slightly rounded chamfer at the end of the threaded shaft, which are additional.  (Please bear in mind length is nominal - there may  be 1 or 2 mm variation because of batch variation). 

Therefore - when comparing the length shown in the table above to your own engine, you need to take into account the width of the engine casting, engine plates and the height of the nut.  Also, any brackets that you may fit under the bolt head - I have tried to base the length of bolts on not having additional brackets unless I know they were standard (the nuts are normally extra width though and can be narrowed slightly if necessary, or one of the washers omitted

Remember that in some cases, bolts were fitted where there may have only been an engine plate on one side - i.e for the rear of the engine on most SOHC engines, the bolt immediately above the magneto platform has an engine plate only on one side, while the bolt under the magneto has an engine plate on both sides - which is why I make 2 versions of these bolts.  Norton did not bother originally, fitting the same length bolt to both)

Reduced Hex Nuts : for many of the bolts and nuts fitted to Norton motorcycles, the AF (Across Flats) diameter was less than normal commerically available nuts for a given bolt shaft size - the rationale for this was that there was not much room around complex castings, therefore you needed to be able to get access with a smaller spanner.  To allow for this, many of the engine bolts and nuts with these 'reduced head size to shaft diameter' nuts also had a deeper depth of hex as well, to provide as much spanner to hex contact as normal bolts - reducing the chance of 'rounding' the hex when applying a lot of pressure with spanners and providing as much thread on the nuts as possible - but important with the pressure required of engine bolts. 

The nuts shown here replicate the Norton nuts and are deeper than commercially available nuts.  In some cases - i.e. if you are fitting thicker washers or ancillary brackets, you may find the nut is deeper than the bolt allows.  In this case the easiest way I have found to reduce the depth of a nut (if a lathe is not available), is to hold the nut in a ring spanner and place its lower unchamfered face carefully against a linisher (make sure you use suitable safety glasses and gloves when doing this) 

Thread Type:  Engine Bolts on Norton engines tended to come in most of the standard British Whitworth diameters, with the following common thread types, where TPI means 'threads per inch':  1/4" (shaft diameter) x 26 tpi (Threads per inch), 5/16" x 26 tpi, 3/8" x 26 tpi, 7/16" x 20 tpi, 1/2" x 20 tpi.

Most thread profiles were originally BSC (British Standard Cycle), but please note that 7/16" x 20tpi is also a UNF standard thread size and none of the tooling manufacturers will now make the BSC profile tooling - therefore we manufacture this size nut/bolt in UNF profile.  These nuts may fit on original bolts, but can be slightly tighter.

Overall, these nuts are high quality, CNC machine finished to look just as the original Norton items, but in non rusting stainless steel, with original Norton dimensions and profiles.   We linish the hex faces on the bolt heads to ensure crisp finishes and we hope you find the will give that finishing touch to any restoration - or just clean up the look of your oily rag, ride to work Norton!

This is the E3224 3/8" x 26 tpi BSC engine nut as fitted to many Norton engine bolts.  It has the correct 'reduced head' and greater depth than other commercially available nuts of this thread/size - and is CNC made specially by us for fitting to Norton engine bolts, but in stainless steel 

New Batch Now in Stock - Aug 2023: (price of this stainless bar tripled since last made 3 years ago!  . . our price only risen a small percentage of that)

This (deeper type/Reduced hex) nut was used on numerous SOHC, OHV and SV engine bolt applications (see our other SOHC engine bolts, but it was also used on OHV/SV 3/8" engines - often fitted on both ends of an engine stud), as well as being listed as the nut holding the brake arm on to the brake shoe cam, and also used to secure the 6v horn to the chassis, and the megaphone exhaust megga securing nut on racing models. They are also listed in numerous places on the fittings of Norton Sidecars!  A very useful nut, as they have a deeper depth of thread than other commercially available nuts - so give more strength, hence why used so frequently on Norton models

Bolt Table Legend and Useful Information: 

AF = "Across Flats', i.e the diamter in inches of hex bar between the two opposite flats - this is the diameter the spanner gap needs to be - we use the correct 'British Standard' bar, as fitted to all Norton single cylinder motorcycles originally, to fit BSW spanners. 

UH = 'Under Head' Bolt Length, i.e. when measuring the length of the bolt shaft - dimensions are taken from the distance at the base of the hex head to the end of the threaded shaft.  It does not take into account the height of the hex head, or the slightly rounded chamfer at the end of the threaded shaft, which are additional.  (Please bear in mind length is nominal - there may  be 1 or 2 mm variation because of batch variation). 

Therefore - when comparing the length shown in the table above to your own engine, you need to take into account the width of the engine casting, engine plates and the height of the nut.  Also, any brackets that you may fit under the bolt head - I have tried to base the length of bolts on not having additional brackets unless I know they were standard (the nuts are normally extra width though and can be narrowed slightly if necessary, or one of the washers omitted

Remember that in some cases, bolts were fitted where there may have only been an engine plate on one side - i.e for the rear of the engine on most SOHC engines, the bolt immediately above the magneto platform has an engine plate only on one side, while the bolt under the magneto has an engine plate on both sides - which is why I make 2 versions of these bolts.  Norton did not bother originally, fitting the same length bolt to both)

Reduced Hex Nuts : for many of the bolts and nuts fitted to Norton motorcycles, the AF (Across Flats) diameter was less than normal commerically available nuts for a given bolt shaft size - the rationale for this was that there was not much room around complex castings, therefore you needed to be able to get access with a smaller spanner.  To allow for this, many of the engine bolts and nuts with these 'reduced head size to shaft diameter' nuts also had a deeper depth of hex as well, to provide as much spanner to hex contact as normal bolts - reducing the chance of 'rounding' the hex when applying a lot of pressure with spanners and providing as much thread on the nuts as possible - but important with the pressure required of engine bolts. 

The nuts shown here replicate the Norton nuts and are deeper than commercially available nuts.  In some cases - i.e. if you are fitting thicker washers or ancillary brackets, you may find the nut is deeper than the bolt allows.  In this case the easiest way I have found to reduce the depth of a nut (if a lathe is not available), is to hold the nut in a ring spanner and place its lower unchamfered face carefully against a linisher (make sure you use suitable safety glasses and gloves when doing this) 

Thread Type:  Engine Bolts on Norton engines tended to come in most of the standard British Whitworth diameters, with the following common thread types, where TPI means 'threads per inch':  1/4" (shaft diameter) x 26 tpi (Threads per inch), 5/16" x 26 tpi, 3/8" x 26 tpi, 7/16" x 20 tpi, 1/2" x 20 tpi.

Most thread profiles were originally BSC (British Standard Cycle), but please note that 7/16" x 20tpi is also a UNF standard thread size and none of the tooling manufacturers will now make the BSC profile tooling - therefore we manufacture this size nut/bolt in UNF profile.  These nuts may fit on original bolts, but can be slightly tighter.

Overall, these nuts are high quality, CNC machine finished to look just as the original Norton items, but in non rusting stainless steel, with original Norton dimensions and profiles.   We lightly linish the hex faces on the bolt heads to ensure crisp finishes and we hope you find the will give that finishing touch to any restoration - or just clean up the look of your oily rag, ride to work Norton!

This is the E3223 5/16" x 26 tpi BSC cradle engine bolt - two of which were fitted to each Norton single engine fitted to a cradle frame.  It has the correct 'reduced head' and greater depth than other commercially available nuts of this thread/size - and is CNC made specially by us for fitting to Norton engine cradle bolts, but in stainless steel (with linished flats).

Note:  We also sell the cradle engine bolt sets, complete with this nut and two stainless washers - these are item 0716.

This nut is approximately 8mm in depth, about half as much again as most commercially available BSC nuts.  As well as making them more suitable for this cradle bolt (I have found that using a normal 'thin' nut on these cradle bolts will eventually result in both a stripped nut, and often the bolt losing its thread) - this nut can also be used on any other 5/16 BSC fastening that needs a 'full' nut for additional strength

Bolt Table Legend and Useful Information: 

AF = "Across Flats', i.e the diamter in inches of hex bar between the two opposite flats - this is the diameter the spanner gap needs to be - we use the correct 'British Standard' bar, as fitted to all Norton single cylinder motorcycles originally, to fit BSW spanners. 

UH = 'Under Head' Bolt Length, i.e. when measuring the length of the bolt shaft - dimensions are taken from the distance at the base of the hex head to the end of the threaded shaft.  It does not take into account the height of the hex head, or the slightly rounded chamfer at the end of the threaded shaft, which are additional.  (Please bear in mind length is nominal - there may  be 1 or 2 mm variation because of batch variation). 

Therefore - when comparing the length shown in the table above to your own engine, you need to take into account the width of the engine casting, engine plates and the height of the nut.  Also, any brackets that you may fit under the bolt head - I have tried to base the length of bolts on not having additional brackets unless I know they were standard (the nuts are normally extra width though and can be narrowed slightly if necessary, or one of the washers omitted

Remember that in some cases, bolts were fitted where there may have only been an engine plate on one side - i.e for the rear of the engine on most SOHC engines, the bolt immediately above the magneto platform has an engine plate only on one side, while the bolt under the magneto has an engine plate on both sides - which is why I make 2 versions of these bolts.  Norton did not bother originally, fitting the same length bolt to both)

Reduced Hex Nuts : for many of the bolts and nuts fitted to Norton motorcycles, the AF (Across Flats) diameter was less than normal commerically available nuts for a given bolt shaft size - the rationale for this was that there was not much room around complex castings, therefore you needed to be able to get access with a smaller spanner.  To allow for this, many of the engine bolts and nuts with these 'reduced head size to shaft diameter' nuts also had a deeper depth of hex as well, to provide as much spanner to hex contact as normal bolts - reducing the chance of 'rounding' the hex when applying a lot of pressure with spanners and providing as much thread on the nuts as possible - but important with the pressure required of engine bolts. 

The nuts shown here replicate the Norton nuts and are deeper than commercially available nuts.  In some cases - i.e. if you are fitting thicker washers or ancillary brackets, you may find the nut is deeper than the bolt allows.  In this case the easiest way I have found to reduce the depth of a nut (if a lathe is not available), is to hold the nut in a ring spanner and place its lower unchamfered face carefully against a linisher (make sure you use suitable safety glasses and gloves when doing this) 

Thread Type:  Engine Bolts on Norton engines tended to come in most of the standard British Whitworth diameters, with the following common thread types, where TPI means 'threads per inch':  1/4" (shaft diameter) x 26 tpi (Threads per inch), 5/16" x 26 tpi, 3/8" x 26 tpi, 7/16" x 20 tpi, 1/2" x 20 tpi.

Most thread profiles were originally BSC (British Standard Cycle), but please note that 7/16" x 20tpi is also a UNF standard thread size and none of the tooling manufacturers will now make the BSC profile tooling - therefore we manufacture this size nut/bolt in UNF profile.  These nuts may fit on original bolts, but can be slightly tighter.

Overall, these nuts are high quality, CNC machine finished to look just as the original Norton items, but in non rusting stainless steel, with original Norton dimensions and profiles.   We linish the hex faces on the bolt heads to ensure crisp finishes and we hope you find the will give that finishing touch to any restoration - or just clean up the look of your oily rag, ride to work Norton!

This listing is for the mounting stud used on magnetos fitted to Norton SOHC Crankcases - normally there were 3 studs fitted to the base of the magneto when used on Norton SOHC engines (both Lucas and BTH platform mount magnetos were made with 4 studs fitted - but the Norton SOHC crankcase design, which had the magneto platform mount cast into the Timing side crankcase, only had provision for 3 stud mounting - so the 4 magneto stud was removed).  If you are buying these studs for a Non-Norton marque, it is more likely you will need to fit 4 studs.  

We CNC manufacture these studs to the original dimensions in stainless steel, with two lengths being offered - one fractionally longer than the other, to fit both Lucas 'Magdyno' type magnetos and most BTH KD1 style magnetos.

This is the slightly shorter version (just the 'coarse' BSW thread is different, other dimensions are the same), the dimensions being:

- Overall length (tip to tip, including chamfers):  1.186"/30.13mm

- Length of BSW (Coarse) thread, from inner start of thread to tip of chamfer: 0.408"/10.3mm

We offer this shorter type - as most often fitted to Lucas Magdyno type magnetos, and also Item 1168, which has a fractionally longer Coarse thread.  Check your magneto before ordering - as both Lucas and BTH magnetos had variations over the years they were manufactured - but in general, this shorter type is most often fitted to Lucas Magdyno while the BTH magnetos often had a slightly deeper hole for Item 1168.

These studs are CNC manufactured by us in stainless steel.  Each stud has two thread types - the coarse (BSW) thread screws into the base of the magneto and is correct for both Lucas Magdyno threads and BTH KD1 magnetos (but please check your magneto has not been modified - as sometimes owners would bore out the thread to a bigger size if the thread got damaged).  The other end of the stud has a BSC fine thread, and is as per original studs, i.e. those fitted to Norton SOHC models (but a similar fine thread was also used on studs on other marques in many cases).

Note: we also sell the magneto stud nuts to fit these studs - See Item 1169 for standard length nuts (2 of this type being fitted per Norton SOHC engine, or often - 4 of these fitted, when fitted to some non-Norton makes), and also the extra long 'wasted' nut - that fitted on the 3rd stud on SOHC models - protruding out from under the rear engine plates - Item 1170 for pre-Featherbed models and Item 1171 for Featherbed models.

It is difficult to be definitive about length - as there were so many variations of both Lucas and BTH magnetos offered over the years (and lengths can vary even on similar magnetos - by batch) - but in general, it seems that the Lucas type stud had a fractionally shorter BSW (coarse) thread going into the base of the magneto.  And to back this up - the 1948 Norton Spare Parts Catalog lists 2 different studs for SOHC engines - Part Number E4267 being for Lucas magnetos (our Item 1167) and E6270 being for BTH magnetos (our Item 1168).

Therefore, as part of manufacturing this stud - and testing against a variety of original Lucas and BTH magnetos (see photos of two of these, the Lucas shown in the photo is a rarer Lucas rotating points type, as fitted to Norton International models up to 1936, but we also tested against a later 1950's Lucas 'facepoint' type magneto) - and have produced two length of studs, which emulate the original length studs we found most common.  

Both Stud lengths (Item 1167 and 1168) do the same job, and both should fit most magnetos - but we have manufactured both types so you can choose the one best suited to your specific magneto.  Please remember that when fitting these studs to a magneto - they will often screw in at least 1mm further than the dimensions stated above - as most magneto stud holes have a slight countersink.

Price is per stud

This listing is for the mounting stud used on magnetos fitted to Norton SOHC Crankcases - normally there were 3 studs fitted to the base of the magneto when used on Norton SOHC engines (both Lucas and BTH platform mount magnetos were made with 4 studs fitted - but the Norton SOHC crankcase design, which had the magneto platform mount cast into the Timing side crankcase, only had provision for 3 stud mounting - so the 4 magneto stud was removed).  If you are buying these studs for a Non-Norton marque, it is more likely you will need to fit 4 studs.  

We CNC manufacture these studs to the original dimensions in stainless steel, with two lengths being offered - one fractionally longer than the other, to fit both Lucas 'Magdyno' type magnetos and most BTH KD1 style magnetos.

This is the slightly longer version (just the 'coarse' BSW thread is different, other dimensions are the same), the dimensions being:

- Overall length (tip to tip, including chamfers):  1.265"/32.1mm

- Length of BSW (Coarse) thread, from inner start of thread to tip of chamfer: 0.485"/12.3mm

This longer stud type seem to have been most commonly fitted to BTH KD1 type platform magnetos.  Check your magneto before ordering - as both Lucas and BTH magnetos had variations over the years they were manufactured - but in general, this longer type was most often fitted to BTH magnetos, while often, theLucas Magdyno would have a slightly shallower hole and require the shorter version - our Item 1167.

These studs are CNC manufactured by us in stainless steel.  Each stud has two thread types - the coarse (BSW) thread screws into the base of the magneto and is correct for both Lucas Magdyno threads and BTH KD1 magnetos (but please check your magneto has not been modified - as sometimes owners would bore out the thread to a bigger size if the thread got damaged).  The other end of the stud has a BSC fine thread, and is as per original studs, i.e. those fitted to Norton SOHC models (but a similar fine thread was also used on studs on other marques in many cases).

Note: we also sell the magneto stud nuts to fit these studs - See Item 1169 for standard length nuts (2 of this type being fitted per Norton SOHC engine, or often - 4 of these fitted, when fitted to some non-Norton makes), and also the extra long 'wasted' nut - that fitted on the 3rd stud on SOHC models - protruding out from under the rear engine plates - Item 1170 for pre-Featherbed models and Item 1171 for Featherbed models.

It is difficult to be definitive about length - as there were so many variations of both Lucas and BTH magnetos offered over the years (and lengths can vary even on similar magnetos - by batch) - but in general, it seems that the Lucas type stud had a fractionally shorter BSW (coarse) thread going into the base of the magneto.  And to back this up - the 1948 Norton Spare Parts Catalog lists 2 different studs for SOHC engines - Part Number E4267 being for Lucas magnetos (our Item 1167) and E6270 being for BTH magnetos (our Item 1168).

Therefore, as part of manufacturing this stud - and testing against a variety of original Lucas and BTH magnetos (see photos of two of these, the Lucas shown in the photo is a rarer Lucas rotating points type, as fitted to Norton International models up to 1936, but we also tested against a later 1950's Lucas 'facepoint' type magneto) - and have produced two length of studs, which emulate the original length studs we found most common.  

Both Stud lengths (Item 1167 and 1168) do the same job, and both should fit most magnetos - but we have manufactured both types so you can choose the one best suited to your specific magneto.  Please remember that when fitting these studs to a magneto - they will often screw in at least 1mm further than the dimensions stated above - as most magneto stud holes have a slight countersink.

Price is per stud

This listing is for the 'standard' length nut  that fits both our Lucas and BTH magneto mounting studs on SOHC engines.  This same nut can also be used on other motorcycle marques using either Lucas and BTH platform magnetos - but double check stud threads if you are not fitting them to our magneto studs (Item 1168 or 1169) - ours are 3/8" x 26tpi BSC thread, as most original magneto studs were from 1930's through to the 1950's.

These nuts are CNC manufactured to original dimensions and width of original magneto stud nuts (which can vary slightly over the years) with an overall depth of 9.5mm  (deeper than most commercial nuts)  - but if you look at our nuts you will see we have manufactured them with a slight lip to one face - this being the face that you screw the nut on to the magneto stud. The other side (the spanner side) has a normal chamfer. They are CNC bar turned from the correct suze imperial (Whitworth spanner size) hex stainless steel.

The reason for including a slight lip on these nuts - on Norton SOHC platforms, the stud fits through the crankcase timing side magneto platform (either an aluminium or magnesium alloy casting) - and although they should always be fitted with a washer under the nut - as they screwed on from underneath - if for whatever reason the washer drops away while undertaking magneto maintenance or adjustment, then the sharp hex edges of a normal type nut wont bite into the casting and damage the face with our type, or make tigtening more difficult. 

As a final point - almost all Norton SOHC magneto's were mounted with just 3 studs (the fourth hole/stud on the platform magneto not being used on SOHC engines, as there was only provision for 3 studs) - for the two front studs - this type of nut was fitted, while the rearmost stud (as it fitted between the rear engine plates) was normally much longer (see our Items 1170 and 1171) - but both of these longer rear studs were also 'wasted' so their ends that make contact with the mag platform are not hex.

These nuts are CNC machined by us in stainless steel with the correct Imperial spanner size that was originally used on most Lucas and BTH magnetos.  Note - this nut looks similar to some other 3/8" BSC Norton nuts we produce, but the depth and lip are specific to this nut type.  However, there is no reason why this nut cannot be used on other Lucas/BTH platform mount magnetos for other marques.  We recommend always fitting a washer when fitting these nuts - the Norton SOHC magneto platform specifically had machining under the platform to allow for this - to spread the load when the nut is tightened.

It is a shame they are hidden away under the platform mount really - because they are also a very pretty nut!

Price is Each. 

Note - we also sell a SOHC Magneto Nut kit:  consisting of 2 x this nut type, + 1 Extra long rear Magneto Bolt/nut + 3 washers, slightly cheaper when bought as a kit.  This is Item 1170 for pre-Featherbed SOHC engines and Item 1171 for Featherbed models.

The last picture is taken from the 1948 Norton Spare Parts List and shows a BTH racing magneto - as fitted to competition SOHC models, with 3 studs, 2 standard length nuts (numbered 29 in the picture) and a Pre-Featherbed long magneto bolt/nut (our ITem 1170).  But the same fittings are valid for Lucas Magdyno units on roadgoing Norton international and CS1 models.

This listing is for a 'Long Length' magneto bolt/nut - of the type that were fitted on the rear fitting of the magneto platform on SOHC Norton engines.  This type of 'wasted' extra long nut were designed this way - because then they would protrude down beyond the rear engine plates, and so be easily accesable - to allow for magneto chain adjustment.  This extra long type were fitted to all Pre-Featherbed SOHC models. 

These are CNC bar turned to the original 'wasted and 'drilled' dimensions of the original, in the correct imperial (Whitworth spanner size) Hex stainless steel.

Price is Each

This length of magneto bolt were of the length fitted to almost all SOHC Norton engines - of Pre-Featherbed chassis type (i.e. both Rigid and Plunger SOHC models) - and the head of bolt (which is pointing downwards when screwed onto the magneto stud) should protrude very close to the lower edge of the timing side rear engine plate - so it is possible to get a spanner to this bolt/nut easily.  If you have a Featherbed model - we can supply the shorter type that were fitted to the rear magneto stuf of that model as well (see Item 1171).

As per the normal length magneto nuts (our Item 1169) the threads on this long nut are 3/8" x 26tpi and the spanner hex is the standard whitworth spanner as original magneto nuts.

As background:  when doing the engineering drawings for this extra long Nut - I realised it was very difficult to find a bolt that we could be sure was original - as I have seen so many made up ones over the years (they are always very hard to find!).  However, I am indebted to my old friend Stu Rogers (the well known SOHC expert), who was able to confirm the correct dimensions, which we have used.   It should be noted that over the years, there was at least one other design employed (i.e. one which did not have such a 'wasted' outer shaft) - but this design has the benefit of being 'wasted' on its shaft, as well as drilled all the way along its length - and is therefore the lightest type in weight - important on a bike so often used for racing.

As well as being the correct dimensions as original - and machined from stainless steel (meaning it will not rust) - it is also a very pretty fitting - pity most of it is hidden away!!  But at least fitting this correct nut will make adjustment of the magneto chain much easier.

(2023 update - apologies this is not a cheap item, but as you can see there is a far more machinining and material than a standard nut - and the correct imperial Hex stainless is now very difficult to procure - and price almost tripled in 2 years, since 2021!)

This listing is for a Featherbed type 'Long Length' magneto bolt/nut - of the type that were fitted on the rear fitting of the magneto platform on SOHC Norton engines.  This bolt is similar to our Item 1170, but the rear magneto mounting nut on Featherbed road models (i.e Featherbed International) were of this shorter length than the pre-Featherbed type. 

These are CNC bar turned to the original 'wasted and 'drilled' dimensions of the original, in the correct imperial (Whitworth spanner size) Hex stainless steel.

Price is Each

I do not have a Featherbed International myself, but was given the original dimensions of the rear Featherbed International nut by a knowledgable Norton Inter expert so trust they are correct to original spec - as you can see they are similar in general profile to the Pre-Featherbed rear magneto nut (Item 1170) but not as long. If you have a Pre-Featherbed model - see Item 11701).

As per the normal length magneto nuts (our Item 1169) the threads on this long nut are 3/8" x 26tpi and the spanner hex is the standard whitworth spanner as original magneto nuts.

- This is the domed nut used on the top of Norton Manx Plunger petrol tanks - these look beautiful lightly polished when used in conjunction with my stainless dished washer. Price is per each

These domed nuts are patterned on the 5/16" BSC domed nuts used on Bolt-Thru Manx petrol tanks, but are also excellent for the top brackets of Inter Oil tanks - also a visible spot, or actually, anywhere where semi decorative domed cycle nut is required

Manufactured in stainless steel - Employs 5/16" B.S.Cycle thread, so can be used for other purposes if desired.  Particularly, they are handy to use on oil tank bolts, handlebar threads (if using 5/16" cycle threads) and 5/16 BSC chassis and mudguard bolts where the nut is showing

We polish the head of each domed nut (but be aware, although we clean before sending - they can occasionally have a residue bit of black buffing compound on them - just wipe off with a clean rag)