Amal float bowl screw threads

[gripper]

2BA threads are 31.4 threads per inch but the big difference is the thread form which is 47.5 degrees, most other threads are 60 degrees, Whitworth and British Standard Fine are 55 and British Standard Cycle is back at 60 degrees.
So along with your slight difference in diameter, pitch and thread angle. should make for a nice tight fit, stainless screws are just asking to take the thread with them when they come out. I would use copperslip not loctite.

 

[Anonymous]

2BA threads are 31.4 threads per inch but the big difference is the thread form which is 47.5 degrees, most other threads are 60 degrees, Whitworth and British Standard Fine are 55 and British Standard Cycle is back at 60 degrees.
So along with your slight difference in diameter, pitch and thread angle. should make for a nice tight fit, stainless screws are just asking to take the thread with them when they come out. I would use copperslip not loctite.

I agree. Stainless steel and aluminium alloy gall their threads badly as they oxidise.
Ta.

 

[CanukNortonNut]

I lost the float bowl screws off one carb and managed to get home by taking out one screw out of each top.

I keep one spare in my parts kit when traveling.
But good move.
Cheers
T
CNN

 

[CanukNortonNut]

2BA threads are 31.4 threads per inch but the big difference is the thread form which is 47.5 degrees, most other threads are 60 degrees, Whitworth and British Standard Fine are 55 and British Standard Cycle is back at 60 degrees.
So along with your slight difference in diameter, pitch and thread angle. should make for a nice tight fit, stainless screws are just asking to take the thread with them when they come out. I would use copperslip not loctite.

I agree. Stainless steel and aluminium alloy gall their threads badly as they oxidise.
Ta.

Galling usually happens when you have two materials of the same working against each other. Like the slide to the body...e.g. I have not experienced the issue that you bring forward yet I keep my bikes in a garage out of the weather and temp swings. The only time my bikes get wet is when I am at a rally or I am on the road between a weather front and my destination.
but if my engine is warm then there is no oxidization happening and if you drive it often enough then this problem shouldn't happen.
Who am I to argue as it is good to know and watch out for but I probably will not change my ways. Ta.
Cheer,
Thomas
CNN