Drop-in resolution
ETA 2824-2 vs Miyota 8245: do they swap?
Whether the ETA 2824-2 and Miyota 8245 share a case, and what changes if you move between them.
Close in diameter, not a drop-in. The ETA 2824-2 (25.60 mm x 4.60 mm) and Miyota 8245 (26.00 mm x 5.67 mm) are near in size but differ in height, dial feet or layout, so moving between them means a new dial, hands and often a case adjustment.
The ETA 2824-2 is the reference Swiss workhorse automatic, used across mid-range Swiss brands for decades. The Miyota 8245 is the fullest-calendar 8200 member, with day, date and a 24-hour indicator.
They differ in diameter (25.60 mm vs 26.00 mm), height (4.60 mm vs 5.67 mm), beat rate (28,800 A/h (4 Hz) vs 21,600 A/h (3 Hz)), calendar layout (centre seconds, date at 3 vs centre seconds, day and date at 3, 24h sub-hand), winding behaviour. The dimensional benchmark for the whole 11 1/2 ligne core. Any donor claiming 2824 compatibility is measured against 25.60 mm x 4.60 mm with date at 3.
Matching diameter and height is necessary but not sufficient. A donor is only a true drop-in when the dial-foot positions, hand-hole sizes, stem length and calendar layout also match. Two movements can share a case and still need a new dial, re-broached hands or a cut-to-length stem.