Thread type question

[robs ss]

Which means you must make/buy new hardened studs in 3/8-16 and 26 TPI on the nut side. Or make/buy new nuts.

Ron
Would you happen to know if the fine thread (26TPI) is CEI (60 degrees) or Brass (55 degrees)?
My thread gauge isn't that good!
Cheers
Rob

 

[L.A.B.]

Would you happen to know if the fine thread (26TPI) is CEI (60 degrees) or Brass (55 degrees)?

Although commonly thought to be 26 TPI, 60 degree BSC (CEI being obsolete by this time), however, according to AN, the rear head nut (No.2) is Whit Form (3/8" x 26 TPI BSB would be identical) which suggests the stud thread is also 55 degree Whit Form.

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Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Factory Spare Parts for Norton motorcycles built before 2002.

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[robs ss]

Although commonly thought to be 26 TPI, 60 degree BSC (CEI being obsolete by this time), however, according to AN, the rear head nut (No.2) is Whit Form (3/8" x 26 TPI BSB would be identical) which suggests the stud thread is also 55 degree Whit Form.

Motorcycle parts and spares for Norton motorbikes - Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Factory Spare Parts for Norton motorcycles built before 2002.

andover-norton.co.uk

Thanks very much Les - different thread at the rear
That explains why the front nuts from my 650SS will fit onto the head bolts but the rear nut binds up. I was wondering why.
Cheers
Rob

 

[L.A.B.]

Thanks very much Les - different thread at the rear

No, it's just that the thread of the two sleeve nuts isn't mentioned but all three 3/8" studs are the same part, therefore, should be the same Whit Form thread if, that's what it is.

Motorcycle parts and spares for Norton motorbikes - Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Factory Spare Parts for Norton motorcycles built before 2002.

andover-norton.co.uk

 

[robs ss]

No, it's just that the thread of the two sleeve nuts isn't mentioned but all three 3/8" studs are the same part, therefore, should be the same Whit Form thread if, that's what it is.

Motorcycle parts and spares for Norton motorbikes - Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Factory Spare Parts for Norton motorcycles built before 2002.

andover-norton.co.uk

Hmmm - it wouldn't be the first AN part to be "a bit" wrong. And my 650 rear nut isn't lying - it simply won't go on the CEI (BSCY) threads more than 5-6 turns without binding.
We've decided to avoid the issue by not replacing the rear stud. Being in a "cooler" area it probably doesn't need to be helicoiled anyway.
Thanks for your helpful advice (as usual!)
Cheers

 

[L.A.B.]

Hmmm - it wouldn't be the first AN part to be "a bit" wrong.

I queried this with Madnorton of AN when the subject of Whit form threads came up some time ago but didn't get an answer.

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