Bellmatic Crown and Stem

[mistergrumpy]

Can anyone offer any advice in terms of part numbers? I've acquired a Seiko 4006 6031 minus a stem and crown. Cousins list the part numbers as 354805 and 55M22NS1respectively but on buying both (crown from Cousins, stem from obsolete parts as Cousins don't stock) then I find they don't fit together seemingly having different threads. They each fit the movement and case but not each other. I'm lost. I can't find any other part numbers. There is another crown for the 4006 but I tried that and it doesn't fit the case tube being too big.

Anyone have any ideas?

[watchweasol]

Hi  try obsoletewatchandclockparts.com    John Senior he has a wealth of osolete bit and pieces and or speedtimerkollection  in europe or welwynwatchparts.co.uk.  Try Obsoletewatchandclock first probably the best bet....   I have attached the service seet for the 4006 so you should find the corret part Nos to quote.    cheers

Seiko 4006A.pdf

[mistergrumpy]

Thanks for the reply. It's hard to establish what's the crown on that schedule however it appears that this problems been raised on here before after a bit of late night Googling with a member named Vic(?) but it was never updated with a final result. It seems there's a thread difference, somewhere between a 9 and a 10 tap but it wasn't established what went wrong and where. Cousins enquired with Seiko regards the correct part numbers and were passed the numbers as above so I'm wondering if perhaps they're supplying none genuine crowns with a different thread maybe. I don't know whether it's worth trying to locate a genuine one just to try the stem in. I'm already 2 crowns and 3 stems in and would like to avoid the hit and miss scenario.

[jdm]

A crown hole too small for the stem can be re-threaded and locking agent let to secure it.

[mistergrumpy]

True though I reckoned on the correct crown costing just as much as the taps plus I'm curious to know which is the right one. I bought one with a stem off Ebay recently that didn't fit but was advertised as fitting 4006 prefix's. When I tried to return it I got a bit of abuse and an insistence that it was the correct part despite it not fitting the case and then I got blocked from buying anything else! I need to know thr correct crown, it obviously exists.

[jdm]

25 minutes ago, mistergrumpy said:

When I tried to return it I got a bit of abuse and an insistence that it was the correct part despite it not fitting the case and then I got blocked from buying anything else! I need to know thr correct crown, it obviously exists.

If they where only saying fits 4006 and it does letting alone case and crwon, then it was listed correctly.

Edited March 8, 2020 by jdm

[Nucejoe]

What doesn't  fit?    If crown doesn't fit over the case tube. It is the wrong crown. 

If short stem, you can increase it's length.

You can also reduce case tube's OD.

 

[mistergrumpy]

The stem doesn't fit the crown. It's diameter is slightly bigger. The stem, however, does fit the movement and the crown fits the case. Both are the correct ones as suggested by Cousins it's just that they don't fit each other. 

As mentioned above I was sold an 55W06NS on Ebay but that butts up to the crown tube because they're the same diameter. It did however fit the stem.

[Nucejoe]

I have got a Seiko bellmatic, can measure for comparason,

1- The tube's OD.

2- Stems OD 

And see what doesn't match.

[Nucejoe]

Do you think you may have been sold a crown to the bell instead of winding?

[mistergrumpy]

No I definitely haven't been sold an alarm bell button, they look different What's your model number? I'm going to try and get a new battery for my vernier calipers before work today. Reading them manually my stem is 1.0mm which seems right, it's more the crown.

[Jon]

Windingstems.com is a good bet

[mistergrumpy]

Yeah that's how I'm sure I have the correct stem but suspect crown.

[mistergrumpy]

So, as the crown didn't cost much I've just ran a 0.9mm drill into it then the stem and it's worked a treat. I've been able to try the watch now and it's great to hear that alarm for the first time. I'm still curious as to the correct part number but for now I'm smiling. 

[mistergrumpy]

To add some clsure to this in case it's viewed down the line. I contacted Seiko and they confirmed that I had the correct parts, being  stem 354805 and crown 55M22NS1 and therefore the fault must lie in the quality of the parts if they are none genuine especially as they are obsolete.