Skip to content

Free worldwide delivery over £75 ex VAT — coming soon! · Not sure a part fits your build? Ask on the forums or email [email protected]

The Balance Wheel
Movements & Calibres

Common Movement Sizes

Last updated 16 Sep 2026

  • Seiko NH35 / NH36 / 4R36 — ø27.4mm (12½″), height 5.32mm, date/day-date, hacking & hand-wind.
  • ETA 2824-2 / Sellita SW200-1 — ø25.6mm (11½″), height 4.6mm, the workhorse automatic.
  • Miyota 9015 — ø26.0mm, height 3.9mm, thin automatic.
  • Unitas 6497 / 6498 — ø36.6mm (16½″), hand-wind, small seconds at 9 or 6.
  • Valjoux 7750 — ø30.0mm (13¼″), height 7.9mm, automatic chronograph.

Movement size is always given as the diameter across the case-clamp notches, not the widest point of the train bridge — measure a donor movement with calipers before assuming it matches a spec sheet.

More in Movements & Calibres

Still stuck? Ask on the forums.