Seiko 5 GMT (SSK) Mod Parts: What Fits Your SSK001, SSK003, SSK005, and SSK017
Got a Seiko 5 GMT? The SSK001 (black), SSK003 (blue), SSK005 (orange), and SSK017 (yellow) are some of the most moddable watches Seiko has put out in years. The good news: a lot of SKX007 parts already work on it, and even more SRPD parts do. The catch: not all of them, and a couple need a small trick.
Here's the quick answer for every major part. If you only read one thing, read the table.
Parts Compatibility
| Part | SRPD Models | SSK GMT Models | W&S Solution |
|---|---|---|---|
| SKX007 Rotating Bezel | Fit | No - Seiko 5 GMT SSK001 etc models have its own Rotating Bezel | Use our SSK Rotating Bezels - they mount on the SSK and accept SKX007/SRPD inserts |
| SKX007 Bezel Insert | Fit | No - won't seat in the stock SSK bezel | Swap to our SSK Rotating Bezel and your whole SKX007/SRPD insert collection fits |
| SKX007 Crown | No - not screw down crown | No - not screw down crown - SRPD & SSK crowns are interchangeable | Use an SRPD/5KX push-pull crown - our CN0664 fits the SSK |
| SKX007 Glass | Fit | Fit - same 31.5mm size | Use the SSK gasket (it's SRPD-type) - don't reuse an SKX gasket |
| SKX007 Bracelet | Fit - swap the fat spring bars for the original SRPD spring bars | Fit - use the original SSK spring bars, fat spring bars won't fit the lug holes | No extra purchase needed - or use an SRPD bracelet for a factory-style fit |
| SKX007 Hands | Fit | Fit - hour, minute and second hands fit the SSK's 4R34/NH34 movement | Add a separate NH34 GMT hand to complete the 4-hand layout |
| SKX007 Dial | Fit | No - the 4R34/NH34 GMT movement needs a wider dial center hole (2.88mm vs about 2.1mm standard) | Use an NH34-ready dial, or mod the center hole of your dial |
| SKX007 Chapter Ring | Fit | No - SSK ring is taller and carries the 24-hour markings | Use an SSK-specific chapter ring |
Bezel: the SSK has its own
SKX007 and SRPD bezels won't press onto the Seiko 5 GMT case — the SSK uses its own rotating bezel. That's exactly why we machined SSK-specific rotating bezels: they mount straight onto the SSK001/003/005/017 and accept any standard SKX007/SRPD insert on top. One bezel swap and the entire insert catalog opens up for your GMT.
Crown: use an SRPD crown
SRPD and SSK crowns are interchangeable — both use the same push-pull system. So if you're replacing the crown on your Seiko 5 GMT, any of our SRPD/5KX push-pull crowns will do the job, like the CN0664. Your old SKX007 screw-down crown stays in the drawer; different system entirely.
Glass: SKX007 crystals fit
Same 31.5mm crystal size as the SKX007, so our SKX007 sapphire crystals fit the Seiko 5 GMT — a double dome is a nice pick since it gives the taller GMT hand stack a little breathing room. One detail: keep the SSK's own gasket (it's SRPD-type) — don't reuse an SKX gasket.
Bracelet: SRPD bracelets fit — SKX bracelets need one trick
SRPD bracelets fit the Seiko 5 GMT directly — same platform, same lugs. Any straight strap (NATO, rubber, leather) swaps freely too on the shared 22mm lug width.
Already own an SKX007 bracelet? You can use it — but not with its fat spring bars. The SSK's lug holes are smaller, so fat bars won't go in. Use the original spring bars that came with your SSK instead, and the bracelet mounts without buying anything new. Want a perfect factory-style fit? An SRPD bracelet is the clean answer.
The Short Version
Most of the parts bin carries over to a Seiko 5 GMT once you know the three rules: the bezel must be SSK-specific (then your inserts all fit), the crown must be SRPD-type, and bracelets either come from the SRPD line or keep your SSK's original spring bars. Crystals and hands move over almost untouched.
Ready to build? Start with the bezel — it sets the whole look — or browse everything that fits your Seiko 5 GMT in one place.
Got a part that's not in the table? Message us — every question becomes the next guide.