length and thread forms of crankcase studs and screws

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pbu-232

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I have the task of assembling an early Commando engine that has been completely stripped and wonder if anyone has ever recorded the lengths, etc of the countless studs and screws therein? The engine number is 134149, so I am guessing all case threads will be whitworth, I'd also like to know the lengths of the 3 - 3/8"studs that screw into the cylinder head and also the 5/16 ones. My problem is compounded by a tub of plated studs/bolts etc from the complete motorcycle - plus anything else the friend thought he had lying around for years being included. I live in hope!!
 
I hope you find someone with a list. I made a spreadsheet for my '66 N15CS 'pile-o-parts'. I documented what I had versus what I thought I needed. Referencing Andover Norton's excellent diagrams, I cross-referenced to a 'NORTON - MATCHLESS - AJS LIST' AKA 'stainless fasteners' which can be found here.

The fasteners list is not 100% complete, but it's close enough - quite beneficial. With a micrometer and a thread gauge, I sorted things out quite well. I believe early Commandos may be a hodge-podge of threads as they moved towards standardization, but I'm no expert. A quick check on Andover's 68-70 Commando engine diagram provides an example - some fasteners show the thread and length, others don't, like this:

Andover shows #142, with only STUD - CARBURETTOR PN 06.0577

So, looking up 06--0577 on the stainless fasteners list shows STUD UNF 5/16"x24x1". Note that Andover PN's are dots, not dashes, always a pain but eh. Figured it out.

Cylinder head studs like #110 (which is 5/16) 'CYLINDER BASE STUD (STEPPED) (NMT2209)'

is listed as 5/16"x26-3/8"x 16x 1-5/8"

And 06.7726, which is 3/8" #111 'CYLINDER BASE STUD (NM18943)'

is listed as 3/8"x16-26x1-1/2"

So you can measure and reference, presto, bingo, done-diddly-done!
 
Last edited:
gpzkat said:
I hope you find someone with a list. I made a spreadsheet for my '66 N15CS 'pile-o-parts'. I documented what I had versus what I thought I needed. Referencing Andover Norton's excellent diagrams, I cross-referenced to a 'NORTON - MATCHLESS - AJS LIST' AKA 'stainless fasteners' which can be found here.

The fasteners list is not 100% complete, but it's close enough - quite beneficial. With a micrometer and a thread gauge, I sorted things out quite well. I believe early Commandos may be a hodge-podge of threads as they moved towards standardization, but I'm no expert. A quick check on Andover's 68-70 Commando engine diagram provides an example - some fasteners show the thread and length, others don't, like this:

Andover shows #142, with only STUD - CARBURETTOR PN 06.0577

So, looking up 06--0577 on the stainless fasteners list shows STUD UNF 5/16"x24x1". Note that Andover PN's are dots, not dashes, always a pain but eh. Figured it out.

Cylinder head studs like #110 (which is 5/16) 'CYLINDER BASE STUD (STEPPED) (NMT2209)'

is listed as 5/16"x26-3/8"x 16x 1-5/8"

And 06.7726, which is 3/8" #111 'CYLINDER BASE STUD (NM18943)'

is listed as 3/8"x16-26x1-1/2"

So you can measure and reference, presto, bingo, done-diddly-done!
Click to expand...
You'd be a lot better off you can contribute to getting it right here: https://gregmarsh.com/MC/FastenersList.aspx

And this will tie together 41 parts manuals along with the fasteners where possible: https://gregmarsh.com/MC/PartsList.aspx

Stainless fasteners (actually stainlessbits.com) has been gone for many years.
 
gpzkat said:
I hope you find someone with a list. I made a spreadsheet for my '66 N15CS 'pile-o-parts'.
Click to expand...

CEI (Cycle) became BSC (British Standard Cycle) in 1938 and the 20 TPI series was apparently dropped, replaced by 20 TPI Whit Form...
length and thread forms of crankcase studs and screws
length and thread forms of crankcase studs and screws
length and thread forms of crankcase studs and screws

...also some Norton threads previously thought to be 60 degree Cycle thread are turning out to be 55 degree Special Whitworth (Whit Form) for instance according to AN the 06.7870/NM24250 Commando rear cylinder head and pre-Unified base stud nut is Whit Form therefore the studs should also be Whit Form not Cycle.
andover-norton.co.uk

Andover Norton - CYLINDER BASE/ HEAD NUT 3/8

CYLINDER BASE/ HEAD NUT 3/8
andover-norton.co.uk
 
gpzkat said:
I hope you find someone with a list. I made a spreadsheet for my '66 N15CS 'pile-o-parts'. I documented what I had versus what I thought I needed. Referencing Andover Norton's excellent diagrams, I cross-referenced to a 'NORTON - MATCHLESS - AJS LIST' AKA 'stainless fasteners' which can be found here.

The fasteners list is not 100% complete, but it's close enough - quite beneficial. With a micrometer and a thread gauge, I sorted things out quite well. I believe early Commandos may be a hodge-podge of threads as they moved towards standardization, but I'm no expert. A quick check on Andover's 68-70 Commando engine diagram provides an example - some fasteners show the thread and length, others don't, like this:

Andover shows #142, with only STUD - CARBURETTOR PN 06.0577

So, looking up 06--0577 on the stainless fasteners list shows STUD UNF 5/16"x24x1". Note that Andover PN's are dots, not dashes, always a pain but eh. Figured it out.

Cylinder head studs like #110 (which is 5/16) 'CYLINDER BASE STUD (STEPPED) (NMT2209)'

is listed as 5/16"x26-3/8"x 16x 1-5/8"

And 06.7726, which is 3/8" #111 'CYLINDER BASE STUD (NM18943)'

is listed as 3/8"x16-26x1-1/2"

So you can measure and reference, presto, bingo, done-diddly-done!
Click to expand...
Thanks, I will look at Andover's engine diagram as a start then the other avenue suggested.
 
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