Pillar bolt thread 2ba ?

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baz

baz

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Could someone confirm that that the thread in the timing cover points housing for the points pillar bolt is 2ba ?
Cheers
 
Hi Baz I just fitted 2ba but I believe they are 3/16 bsf.
 
Chris said:
Hi Baz I just fitted 2ba but I believe they are 3/16 bsf.
Click to expand...
Looks like 2ba is almost the same as 3/16 BSF on the thread pitch and diameter so I'm not surprised they fit
I'd like to know exactly what they are
It's not actually for a commando but a BSA b50 but as far as I know they all use the same pillar bolt and I want to order a Heli cert set
Cheers
 
They are 2BA.
Pillar bolt thread 2ba ?
 
Just got to decide whether to buy a helicoil kit or make an insert
Cheers
 
baz said:
Could someone confirm that that the thread in the timing cover points housing for the points pillar bolt is 2ba ?
Cheers
Click to expand...
andover-norton.co.uk

Andover Norton Parts Drawings - Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk

2BA are the cover screws into the pillar bolts, assume the pillar bolts have the same thread? will check and confirm..
 
Satan's Aardvark said:
andover-norton.co.uk

Andover Norton Parts Drawings - Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk

2BA are the cover screws into the pillar bolts, assume the pillar bolts have the same thread? will check and confirm..
Click to expand...
Yes I believe they are the same thread
I hope so,I've just ordered a 2ba thread repair kit!
Cheers
 
I just screwed the outer screw into the timing cover thread.
 
Time Warp said:
I just screwed the outer screw into the timing cover thread.
Click to expand...
Ok cheers for confirming that
I won't be any where near that engine until very late tonight
Funny how going to work uses the day up!!!!
 
I've used M3 Timeserts on Concentrics to repair knackered 2BA threads in the past
 
I think more like 4.5 mm (measuring an original and new AN parts which had a 0.1 mm difference between them in diameter)
Even though the spec is 0.185" / 4.669 mm.

A very sloppy fit in a new M5 nut.
 
In UK engineering (pre metric) it is usual to not use BSF threads below 1/4” but to go to BA threads instead. However 2BA and 3/16”BSF are classed as interchangeable as the diameter and thread pitch are so similar.
 
The tapping drill size for 2BA is 4mm, so M5 is close diameter wise, M3 would not even touch the sides.
 
The tapping size for M5 / 0.8 is 4.2 mm / thread angle 60° , if you elect to put a 2BA screw (thread angle 47.5°) into a M5 thread my first recommendation would be JB Weld or Loctite 660 if you want it removable. (jk)

The pitch ratio is similar at 1.23 / 2BA to 1.25 on the M5/0.8.
A 2BA thread might be easier in the long run even if the tapping size is 4.1 mm.

I like to try and reinvent the square wheel but this would not be one of those times. (imho)
 
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