Pocket watch mainspring advice

[Andyworks]

Good afternoon all
I am after a mainspring for an old pocket watch. The height is 3.38mm with a thickness of 0.25mm and a length of 53.5cm. The inside diameter of the barrel is 17.8mm. The end that hooks onto the inside of the barrel has a hole in it only. I can't find the spring on Cousins website and I don't have the GR code. I found this one 34025560195 which is near. I have asked if it has a hole in the barrel attatchment end but got told it has a normal end so am unsure what is considered normal.

If anyone could please help with this it would be most appreciated.

Many thanks

 

Andy

 

 

[TimFitz]

I can't answer your question as you posted it.   

When I need a mainspring for a vintage P/W I go to EBAY or Daves watch parts and search for " Mainspring for (say) hamiltion 992 B " and you will find exactly what your looking for..

[Andyworks]

Hi

 

Thanks Tim. I can't search for the movement unfortunately as it was made in 1901 and it has no markings on it. I know the date and the case maker only but have no model number etc so am struggling. The enamel dial doesn't have any name on it either. I was asking that based on thmeasurements given of the original spring would the product code listed on the cousins website be a suitable replacement as it does not list what barely attachment end it has in the code as say a GREEN code would?

 

I do not have a GR code book but searching on the site showed no such code for the spring I require. Apologies for the way I asked the question in my original post as looking back it was not clear :-(

 

Andy

[Andyworks]

Hi

 

Green should read GR. Apologies for that auto correction kicked in on this tablet.

 

Andy

[StuartBaker104]

The spring you have found on Cousins is a bit long... but you are probably going to have to modify one anyway as they don't have any hole end springs near the size you need. I would go for 3402354017 (no idea why Cousins have stopped listing by GR number)

See this page for more info on calculating what the best match would be as you may not have that fitted today http://www.vintagewatchstraps.com/blogmainsprings.php#

The standard (non-automatic) spring has a hooked end, but you can cut this off and punch a hole... see here for more 

 

 

[Andyworks]

Thank you so much for the reply Stuart it was most helpful. Would there be anything stopping me using a hooked end in a barrel that has a rivet in it to hold the spring as it would prevent the spring from rotating when being wound up and free length tension in the spring from being coiled up would hold it tight against the barrel inner wall? Just wondering out of interest more than anything. I still find it fascinating getting to learn how to order parts etc.

 

Again many thanks to everyone who has posted answers and provided me with guidance.

 

Andy

 

[StuartBaker104]

Surely your pride would stop you?

I have seen it done, but I wouldn't do it

 

[Andyworks]

Was just wondering as I serviced a pocket watch recently that was like this as the hook in the barrel looked similar but it had a hooked spring fitted to it. I will modify the spring you suggested as it is easily done. I am a perfectionist sadly so it has to be done right.

 

[mrbloke]

They probably mean it has a hook end, (outer end)