BEGINNER SERIES · 01 · CHOOSE YOUR PROJECT
A Seiko mod is a watch you customise with replacement parts. You can change an existing watch or assemble a new watch around a compatible movement. We suggest choosing the type of project before you choose a dial colour or fill a shopping cart.
Choose a starting point that suits you
- A strap or bracelet change: Start here if you want to work on a watch without opening its case. Check the lug width, spring bars and, for fitted bracelets, the end-link compatibility.
- A donor-watch mod: Change selected parts on a watch you own. Record its exact reference first. A similar-looking case can use different crystals, bezels or crowns.
- A new build: Choose a case, movement, dial and hands as a compatible set. A case with the crystal installed and a matched crown can reduce the jobs you need to learn at once.
For a first full build, we suggest a straightforward three-hand watch. The TMI NH35 provides hours, minutes, seconds and a date. A GMT adds another hand and more clearance checks; you can tackle that after you finish a simpler project.
Understand the labels before you buy
OEM means original equipment manufacturer. Aftermarket means a part from an independent supplier. A new watch assembled with a TMI movement and aftermarket parts is a custom build, rather than a factory-built Seiko. Read each listing for the origin and specification of that component.
Write a short build brief
- Choose its job. Decide whether you want an everyday watch, a dress watch or a dive-style design. A dive-style appearance does not establish water resistance.
- Check the fit. Compare case diameter, lug-to-lug length and thickness with a watch you enjoy wearing. Lug-to-lug is the distance between the ends of the case lugs.
- Keep the display readable. Choose hands that contrast with the dial and reach the appropriate markings. Decide whether you need a date window.
- Pick one case platform. Start with the case's stated movement and dial requirements, then check the rest of the parts against them.
Browse our SKX007-compatible cases to compare case styles. The collection name is a starting point; confirm the specifications on the individual listing before choosing the remaining parts.
Budget for the complete job
Separate your budget into parts, tools, spare consumables, delivery and taxes, plus any assembly or pressure-testing service you need. A low parts total can rise if you need extra tools or replace a damaged stem. Keep the original parts from a donor watch labelled and protected.
Your next step: write down the project type, case platform, movement, wrist-fit measurements and total budget. Use our watch-parts checklist to identify unfamiliar components, then read the compatibility guide before ordering.
