Your first watch build

Building a mechanical watch from parts isn't as hard as it sounds. An NH35 movement, an aftermarket case, and a few tools gets you a custom watch in an afternoon. Here's the step-by-step process from unboxing parts to wearing your build.

By Colin B. · Published August 9, 2026

Your first watch build will take about 2-3 hours. Most of that time is setup, alignment, and triple-checking — the actual assembly is surprisingly quick once everything is in position. The NH35 movement is the standard platform because it’s forgiving, well-documented, and compatible with thousands of aftermarket parts.

Here’s the complete build process.

Before you start: Parts and workspace

What you need for a complete build:

• NH35 (or NH36) automatic movement
• Compatible watch case with crystal and caseback
• Dial (28-28.5mm, NH35-compatible)
• Hands set (hour, minute, second — NH35-compatible)
• Stem and crown (often included with case)
• Chapter ring / rehaut (often included with case)
• Gaskets (often included with case)

Your workspace matters. Clear a flat desk. Cover it with a white lint-free cloth or silicone mat — white so you can find dropped screws, lint-free so particles don’t end up on your dial. Position a bright desk lamp at an angle (not directly overhead — that creates shadows in the case). Put your movement holder, hand press, and tweezers within easy reach.

Clean your hands. Wash and dry thoroughly, or wear nitrile gloves. A single fingerprint on the dial or crystal will haunt you every time you look at the watch. Use tweezers for any part that touches the visible interior — dial, hands, chapter ring.

Step 1: Preparing the movement

Remove the movement from packaging. Hold it by the edges only — never touch the top (dial side) or the balance wheel. Set it in your movement holder with the dial side facing up.

Set the stem. The NH35 has a two-position stem: pushed in for winding, pulled out for time-setting. You’ll install the stem through the case later, but first confirm it works: push it in and rotate — you should feel the winding mechanism engage. Pull it out one click and rotate — the second hand should stop (this is “hacking,” and it’s how you set the time precisely).

Remove the stem for now. There’s a small lever near the stem opening — press it with a fine tool while gently pulling the stem out. Set the stem aside in a parts tray. You’ll reinstall it after the movement is in the case.

Attach the dial. The dial has two small feet on the back that correspond to slots on the movement. Align the feet with the slots (usually at 2 o’clock and 8 o’clock positions on the movement plate). Press down gently — the dial feet should click into the slots. The dial should sit flat and not wobble. If it wobbles, a foot isn’t seated correctly.

Step 2: Setting the hands

This is the most delicate step of the build. Take your time.

Remove the movement from the holder and set it dial-up on a soft surface (a movement cushion or folded microfiber cloth).

Install the hour hand first. Using tweezers, pick up the hour hand by the counterweight (the short end). Position it over the hour wheel tube — the small metal tube at the center of the dial. Press down gently with the hand press, using a die that’s wider than the hour wheel tube but narrower than the hand. The hand should seat with a soft click. Test by gently rotating it — it should move freely without dragging on the dial.

Install the minute hand. Same process, but the minute hand seats on a tube that’s one level higher than the hour hand. Use a smaller die on the hand press. After pressing, confirm both hands move freely and don’t touch each other. If the hands touch, one of them isn’t seated at the correct depth — remove and re-press.

Install the second hand last. The second hand presses onto the thinnest pinion at the very center. This is the most delicate operation — the pinion is fragile and the force required is minimal. Some modders skip the hand press for the second hand and use a sharpened wooden dowel instead for more precise control. Press just enough for the hand to stay — if it falls off when you rotate the movement, press a tiny bit more.

Step 3: Casing the movement

Prepare the case. If the case came with a chapter ring, install it now — it drops into the case and sits against the crystal. Check that any gaskets are in position (case back gasket, crystal gasket, crown gasket).

Insert the movement. Hold the case in one hand and lower the movement (with dial and hands attached) into the case. It should drop in and sit flat. The stem hole in the movement should align with the crown tube in the case.

Reinstall the stem. Push the stem through the crown tube and into the movement. You’ll need to press the same small lever you used earlier. When the stem clicks in, test it: push in for winding, pull out for time-setting. If the crown turns freely in both positions and the second hand hacks (stops) when pulled out, the stem is correctly installed.

Install the caseback. Apply a thin layer of silicone grease to the caseback gasket for water resistance (optional for a first build, but good practice). Align the caseback and screw or press it on. For screw-down backs, use your case wrench — tighten until snug, not gorilla-tight. The gasket does the sealing, not the torque.

Step 4: Final checks

Set the time. Pull the crown out to the time-setting position. Set the hands to 12:00 and check alignment — all three hands should point straight up. If the minute hand is off by a visible amount, the hand wasn’t pressed straight and you’ll need to re-open and re-set it. (This is the most common reason for opening a completed build.)

Wind the movement. Push the crown in and rotate it clockwise 30-40 times. The movement should start running. Place the watch dial-up and let it run for a few minutes. Watch the second hand — it should sweep smoothly without stuttering or stopping.

Check hand clearance. Run the time through a full 12-hour cycle quickly (using the crown in time-setting position) and watch for any point where the hands touch each other, the dial, or the crystal. If they touch, you need to re-press the offending hand at a slightly different depth.

Install the strap or bracelet. Use your spring bar tool to attach the strap to the lugs. Push the spring bar in, align with the lug holes, and release. Confirm both sides click into place.

The mistakes that ruin first builds

Fingerprints on the dial. Handle the dial with tweezers only. If you touch it, clean immediately with a lens cloth — dried fingerprint oils are much harder to remove. Some modders wear nitrile gloves for the entire build.

Dust under the crystal. Work in a still room with no fans or open windows. Use a dust blower (a rubber bulb, not canned air — canned air leaves residue) to clear the dial and crystal interior before closing the case. One visible speck of dust on the dial will drive you crazy.

Over-pressing hands. More force does not mean more security. Over-pressing the hour hand can crack the dial. Over-pressing the second hand can bend the pinion. Use the minimum force needed — if the hand stays when you gently shake the movement, it’s on.

Misaligned chapter ring. The chapter ring (the ring with minute markers around the inside of the crystal) needs to be perfectly aligned. Even 1 degree of rotation is visible. Check alignment before installing the caseback — rotating the chapter ring after the movement is cased requires disassembly.

Forgetting to test the crown. Always test crown functions (winding and time-setting) before closing the caseback. Reopening a case to fix a stem issue means redoing the caseback gasket and risking dust contamination.

What to build next

Your first build teaches you the process. Your second build is where you start making design choices:

• Different dial and hands combinations — the visual identity of the watch
• Sapphire crystal upgrade — clearer, more scratch-resistant than mineral
• Bezel insert swaps — different colors and styles change the watch’s character
• Double-dome crystal — a subtle curve that catches light beautifully
• NH36 movement — adds a day/date complication for one more thing to align

The rabbit hole goes as deep as you want. Custom-painted dials, aftermarket rotors, lume relume projects, and full case design are all within reach once you’re comfortable with the basic build process.

Check out our watch modding gear guide for specific product recommendations and current prices.