The SRPD, often called the 5KX, is the modern accessible donor for many Seiko mods. It keeps much of the SKX-style look, adds a hacking and hand-winding movement, and is easier to buy than a discontinued SKX007.
If this is your first build, read the beginner's guide first, then use this page as the platform-specific checklist. Platform names are useful shortcuts, but exact vendor dimensions still matter.
SRPD / 5KX mod profile
Best for
Beginner-friendly donor builds, strap and bezel changes, and practical daily watches where you want current-production availability.
Watch out for
The SRPD is not a true one-to-one SKX007 replacement. Some case parts fit, some do not, and water resistance expectations are different from the original SKX diver line.
Parts checklist
| Part | What to check | Beginner note |
|---|---|---|
| Case | Whether you are keeping the stock case or using aftermarket | A donor SRPD already gives you the case and movement. |
| Movement | Usually 4R36 or NH36-style day-date layout | Choose dials that match day-date unless swapping movement too. |
| Dial | Feet, day-date aperture, and chapter ring clearance | A date-only dial can look wrong with a day-date movement. |
| Hands | Seiko NH sizing and hand stack clearance | Reuse only if removal does not stretch the tubes. |
| Bezel insert | Outer and inner insert dimensions | The listing should name SRPD or 5KX compatibility. |
| Strap or bracelet | Lug width and end link fit | A straight strap is the safest beginner change. |
Buy parts for the exact case in front of you, not just the platform name in the product title.
Suggested build order
| Stage | Why it comes now | Useful next read |
|---|---|---|
| Case and movement | They define the physical constraints for the build. | NH35 movement guide |
| Dial and hands | These set the watch's character and must match the movement. | Hands and lume guide |
| Crystal, bezel, and insert | These change profile and platform fit. | Crystal swap guide |
| Bracelet or strap | Lug width and end link style decide fit. | Parts planner |
Related: SKX007 vs SRPD platform comparison.
Frequently asked questions
Is the SRPD or 5KX good for a first Seiko mod?
Yes. The SRPD and 5KX family is current production, easy to find, and close enough to the SKX007 ecosystem that many common parts are available. It is often the most sensible donor platform for a first mod.
Are SRPD and SKX007 parts interchangeable?
Some are, especially dials, hands, and many bezel inserts. Case-specific parts such as crystals, crowns, bezels, and fitted bracelets need explicit vendor confirmation. Treat interchangeability as likely for simple parts and unproven for case geometry.
What movement is inside an SRPD?
Most SRPD and 5KX models use the 4R36, which is closely related to the NH36. It hacks and hand-winds, so many movement-swap reasons that apply to older 7s26 watches do not apply here.
What is the easiest SRPD mod?
A strap or bracelet swap is the easiest. A bezel insert swap is the next step if the insert dimensions match. Dial and hand work is doable, but it requires dust control and careful hand-setting.
Plan your SRPD / 5KX build before ordering
The builder helps you preview part combinations and spot major compatibility issues before the parts arrive.
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