Need a part for this caliber? Supporters unlock the parts catalog, factory equivalents, and the donor finder that shows which other movements can supply the part you need.
Become a Supporter
Updates to data and images are welcome from our readers.
ETA 2391
Basic Information
| Name | ETA 2391 |
|---|---|
| Manufacturer | ETA |
| Launch Year | 1960 |
| Caliber Family | Description 2390: manual wind, 10.5" 2391: manual wind 2406: manual wind, date 2408: manual, new date mechanism 2450: automatic, 10.5" 2451: automatic 2452: automatic, date 2453: like 2451, but single-material rotor 2454: like 2452, but single-material rotor 2456: automatic, date, 10.5" 2471: automatic, prepared for new date 2472: automatic, new date mechanism Related calibers ETA 2390, ETA 2391, ETA 2392, ETA 2393, ETA 2394, ETA 2395, ETA 2396, ETA 2397, ETA 2398, ETA 2399, ETA 2400, ETA 2401, ETA 2402, ETA 2403, ETA 2404, ETA 2405, ETA 2406, ETA 2408, ETA 2409, ETA 2450, ETA 2451, ETA 2452, ETA 2453, ETA 2454, ETA 2455, ETA 2456, ETA 2457, ETA 2458, ETA 2459, ETA 2460, ETA 2461, ETA 2462, ETA 2463, ETA 2464, ETA 2465, ETA 2471, ETA 2472, ETA 2474, ETA 2475 |
| Is COSC certified | No |
Timegrapher
Beat rate
18,000 bph
Frequency
2.5 Hz
Lift angle
52 degrees
Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.
Technical Details
| Lignes Dimensions | 11.5 ‴ |
|---|---|
| Dimensions | 26 mm |
| Height | 3.6 mm |
| Further Measures | Mounting Diameter (Dm): 25.6mm Stem height (T): 1.85mm Mounting Height (F): 1.4mm |
| Power Reserve | 47 hours |
| Frequency | 18,000 vph |
| Jewels | 21 |
| Lift Angle | 52 degrees |
Complications and Specifications
| Shape | Round |
|---|---|
| Complications |
|
| Shock Protection | Incabloc |
| Regulator Type | Pinned Regulator (or Index Regulator) |
| Movement Type | Manual |
| Escapement Type | Swiss Lever |
| Control Type | Balance Wheel |
| Winding Type | Stem Winding (Crown) |
| Setting Type | Stem Set (Crown Pull) |
Additional Information
| Hand Sizes | 1.50 x 0.90 x 0.21mm |
|---|---|
| Hand Count | 3 |
| Country Of Manufacture | Switzerland |
| Notes | Remarks: early fixed (Fig.3), later mobile stud carrier (Fig.1, 4) differences not known between 2391, 2393, 2395, 2397, 2399, 2401, 2403, 2405 Other data: balance staff: U2226 / U3136 for balance with/without screws stem: W2426, W3226 mainspring / battery: Zf873, 1.30 x 10.0 x 0.11 x 320mm balance staff ronda: 4377 (10,5-11,5) stem ronda: 917 (10,5) Mainspring: 1.300 x 10.000 x 0.110 x 340.000 mm Ranfft mentioned about this caliber: There are variants with this quantity of jewels 17, 21 |
| Signature | 1-2) ca. 1960: Silvana, Swiss Made, 17 Jewels - DH, Patented; Incabloc 3) ca. 1955: Swiss, Suter SU 2391, 17 Jewels; Incabloc 4-5) ca. 1965: DH, Swiss Made, 17 Jewels - Patented; Incabloc |
| Import Codes |
|
Compatible Parts
1411 other caliber(s) share compatible parts with this caliber.
98 compatible part(s) available — Supporter feature.
Metadata
| Created At | Sep 15, 2023 |
|---|---|
| Updated At | Apr 23, 2025, 11:32:08 PM |
Loading...