# Dumb Newbie Seiko Diver Question



## SEIKO7A38 (Feb 12, 2009)

Could anybody please tell me the *exact* thickness in mm of the standard Hardlex crystal used in a SKX007/009/011/173 ?

Also could somebody confirm whether it is actually *flat* or slightly domed, because I've read some conflicting data.

I'm talking about Seiko p/n 315P15HN02, by the way - so I already know that it's 31.5mm diameter.


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## Kutusov (Apr 19, 2010)

I have no idea of the answer but you are hardly a newbie ---------->


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## SEIKO7A38 (Feb 12, 2009)

Kutusov said:


> I have no idea of the answer but you are hardly a newbie ---------->


No, but I *am* a newbie as far as Seiko SKX--- Divers are concerned. :grin: I know nuffin. :duh: Hence the question. :lookaround:


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## Roger the Dodger (Oct 5, 2009)

The crystal on my 009 appears to be totally flat....I put a straight edge across it (difficult, because the crystal is fractionally lower than the surrounding bezel) and could see no doming. Hope this helps. :thumbsup:


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## SEIKO7A38 (Feb 12, 2009)

Roger the Dodger said:


> Hope this helps. :thumbsup:


Thanks, Roger. :thumbup:


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## SEIKO7A38 (Feb 12, 2009)

Found a photo of one in this old post on WUS: http://forums.watchuseek.com/f29/fsot-seiko-skx007-crystal-chapter-ring-$22-310095.html










Still doesn't tell me how thick one is though. :huh:


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## Kutusov (Apr 19, 2010)

Roger the Dodger said:


> The crystal on my 009 appears to be totally flat....I put a straight edge across it (difficult, because the crystal is fractionally lower than the surrounding bezel) and could see no doming. Hope this helps. :thumbsup:





SEIKO7A38Fan said:


> Found a photo of one in this old post on WUS: http://forums.watchuseek.com/f29/fsot-seiko-skx007-crystal-chapter-ring-$22-310095.html
> 
> 
> 
> ...


You'll have to ask Roger to take his crystal out and measure it for you :black eye:

fftopic2: Isn't there a "naughty" smiley anymore? I can never find the one I want but with these new ones I feel completely lost fftopic2:

EDIT: Oh, there it is! :naughty:


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## SEIKO7A38 (Feb 12, 2009)

Kutusov said:


> You'll have to ask Roger to take his crystal out and measure it for you :black eye:


I'm sure there are other forum members who have had plenty of experience of modding SKX Divers who know the answer.









No names mentioned, but ....



mrteatime said:


> modded seiko skx007


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## Kutusov (Apr 19, 2010)

SEIKO7A38Fan said:


> I'm sure there are other forum members who have had plenty of experience of modding SKX Divers who know the answer.
> 
> 
> 
> ...


I know you don't want to mention names so I have no idea who you're talking about... but I just remembered that... what's'name... mrteatime might know! :smartass: 

Drop him a PM!


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## mrteatime (Oct 25, 2006)

that is torture posting that 

i must get round to doing another one of those.....although the tuna would look cool in yellow


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## Kutusov (Apr 19, 2010)

mrteatime said:


> although the tuna would look cool in yellow


 :shocking:







Don't you dare!!!! :comando:


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## mrteatime (Oct 25, 2006)

Kutusov said:


> mrteatime said:
> 
> 
> > although the tuna would look cool in yellow
> ...


or orange.....


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## Kutusov (Apr 19, 2010)

mrteatime said:


> or orange.....


 :shocking:







Don't you dare!!!! :comando: x 2!!!


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## mrteatime (Oct 25, 2006)

Kutusov said:


> mrteatime said:
> 
> 
> > or orange.....
> ...


i have something very special lined up for my baby


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## Kutusov (Apr 19, 2010)

mrteatime said:


> i have something very special lined up for my baby


Mate!! It's a Tuna!! Control yourself... pretty please?...


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## SEIKO7A38 (Feb 12, 2009)

O.K. Renato. Enough of the fftopic:

This is what I need to find a crystal for - my rather neglected 7A38-7050 resto' project:



SEIKO7A38Fan said:


> It was kindly donated to my collection (free of charge) by German Seiko collector Michael Rothe.
> 
> Before he sent it, he did warn me that it was a bit of a 'beater' / resto' project:
> 
> ...


I posted that back in December 2009. Since then, my efforts to fix up the watch had stalled. :blush:

The two 31.5mm Ã˜ x 2.5mm crystals which I'd bought, in the hope of using as a replacement:

Sternkreuz p/n MSH315 and Cousins (Superparts) p/n F250CMH315 wouldn't fit under the bezel. 

The Sternkreuz is straight edged, and the Cousins crystal has the tiniest polished bevel, which wasn't enough.

The original Seiko crystal p/n 315W20GN00 (only used on 7A38-7050 and -705A) is obsolete and no longer available. :search:

Even Chris, the crystal specialist at Jules Borel didn't have anything listed as a substitute, when I called her to ask.

Seiko have made literally dozens of different 31.5mm Ã˜ crystals over the years.

Problem is, as we know, Seiko crystal part numbers are only partially significant.

A Seiko crystal with a part number beginning 315xxxxxxxx is always 31.5mm in diameter,

but nothing tells you whether it's flat; domed; how thick, or whether it's got a bevelled edge. 

So yesterday, I decided it was about time, and I ran a search on Cousins on Seiko Glass 315:










I then took each part number in turn, feeding it back into Seiko Oceania's database, doing a reverse look-up - i.e. where used.

Less than half the part numbers from the Cousins search result were recognised.

Most of the p/n's which were recognised were used on 'dressy' 7T32's; 7T34 Flightmasters; 7A28's and 7A48's -

Which would indicate to me that the crystals were likely to be only 1.5mm thick.

Note the 2nd and 3rd part numbers returned in the Cousins search result:

315W20GN00 - the original correct p/n crystal for a 7A38-7050 / -705A.

315P15HN02 - as used on the SKX007/009/011 Divers, which I am hoping might fit.

Hence the original prolonged 'dumb newbie' question. :tongue2:


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## Kutusov (Apr 19, 2010)

SEIKO7A38Fan said:


> O.K. Renato. Enough of the fftopic:


 :shutup:


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## Barryboy (Mar 21, 2006)

mrteatime said:


> that is torture posting that
> 
> i must get round to doing another one of those.....although the tuna would look cool in yellow


Shawn... It looks even better since that naff bezel got changed...



















Rob


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## LuvWatch (May 14, 2004)

Hi Paul, that is a lovely 7A38 :thumbsup:

Maybe I am being thick here, but you would have the dimensions of the original crystal i.e. diameter and thickness - could you not then find a replacement based on these measurements. As you indicate Cousins sapphire range give both the diameter and thickness in their listing :read:

BTW - I have measured an original flat mineral crystal taken out of a 7c43-7010 and it is 32mm (at the flat bottom edge) and about 30.4mm (at the top of edge) due to the bevelled edge and it is 2.5mm thick

Good luck in sourcing the part :yes:

Derek


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## SEIKO7A38 (Feb 12, 2009)

LuvWatch said:


> Maybe I am being thick here, but you would have the dimensions of the original crystal i.e. diameter and thickness - could you not then find a replacement based on these measurements.


Maybe you are, Derek. :duh: See my (re)post at the top of this page:



SEIKO7A38Fan said:


> So far I've sourced a couple of crystals for it (*they're 31.5mm Ã˜ x 2.5mm thick !*)


I'd already (accurately) measured the original crystal's thickness in situ (using the 8mm dies from my crystal press as spacers, in my digital vernier calipers).



LuvWatch said:


> As you indicate Cousins sapphire range give both the diameter and thickness in their listing :read:


But thanks for the tip on the Cousin's Sapphire crystals though - I didn't realise they also did them 2.4mm thick. :thumbsup:

The 'el cheapo' Cousins 31.5mm crystal which I'd already bought was just their plain mineral glass 2.5 thick.

Depends whether their Sapphire range have a polished bevelled top edge (or not). Certainly food for thought. :think:


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## mrteatime (Oct 25, 2006)

doing another one of these rob


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## SEIKO7A38 (Feb 12, 2009)

Before I go any further, I think I'm quite justified in saying, that after the 400+ views this thread has had ....

that I'm very disappointed, ney disgusted, that no-one could be bothered to reply to my original question. :thumbsdown:

Least of all the various self-acclaimed Diver Modders who frequent this forum. :assassin:



SEIKO7A38Fan said:


> Could anybody please tell me the *exact* thickness in mm of the standard Hardlex crystal used in a SKX007 ....


At the weekend, I'd also sent an eMail to Harold 'Yobokies' Ng, asking the same question.

I was, at one point, actually considering buying one of his SKX007 Flat Sapphire crystals:










But he wrote back on Sunday:



> Sorry I only sell domed sapphire for the SKX007 now.


and this morning followed up with this:



> Hi Paul,
> 
> Sorry for the late reply. The original 007 crystal is 3.0mm thick.


In the meantime, I'd got fed up of waiting, and ordered a SKX007 crystal (Seiko p/n 315P15HN02) from Cousins.

The packet arrived yesterday, and first thing I did when I opened it was to measure that crystal. It's *2.96mm* thick.

Undeterred, I stripped down my 7A38-7050, and popped out the original badly scratched 31.5mm Ã˜ crystal.

I measured it again, and it's actually 2.53mm thick.

The SKX007 crystal had a rather more pronounced bevelled edge, so despite being nearly half a mil' thicker,

I thought I'd try fitting it anyway. It went in, after giving it a bit of welly. :sweatdrop: SKX crystal into 7A38 will go. :hammer:


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## Kutusov (Apr 19, 2010)

SEIKO7A38Fan said:


> Before I go any further, I think I'm quite justified in saying, that after the 400+ views this thread has had ....
> 
> that I'm very disappointed, ney disgusted, that no-one could be bothered to reply to my original question. :thumbsdown:
> 
> Least of all the various self-acclaimed Diver Modders who frequent this forum. :assassin:


Shame on you all!! At least I tried keeping Paul's hopes up with all my fftopic2:


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## Roger the Dodger (Oct 5, 2009)

Kutusov said:


> SEIKO7A38Fan said:
> 
> 
> > Before I go any further, I think I'm quite justified in saying, that after the 400+ views this thread has had ....
> ...


Well, I did say it was flat....(3rd reply , I think), but as I couldn't actually take it out of the watch and measure it with my super accurate, highly technical, super spec't Â£7.99 Lidl vernier calipers, I thought that might be enough....

Just jokin', Paul :good: :lol: :lol: :lol:


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## The Padd (Sep 12, 2021)

This is probably the only place on the entire internet that confirms the original crystal size is 31.5m dia by just shy of 3mm thick.

Mod sites are very bad at providing information on the actual thickness of the crystals they sell and how they compare to the original, meaning you have to buy all their parts to build a watch of a certain style.

Time to buy a cheap chinese sapphire and a cheap bezel insert to see if I can make it all work!


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