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Hamilton 661
Basic Information
| Name | Hamilton 661 |
|---|---|
| Alternative Name | Certina 25-45 |
| Base Calibre | Certina 25-45 |
| Manufacturer | Hamilton |
| Launch Year | 1951 |
| Caliber Family | Description 661: - 690: date Related calibers Hamilton 661, Hamilton 690 |
| Is COSC certified | No |
Timegrapher
Beat rate
18,000 bph
Frequency
2.5 Hz
Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.
Technical Details
| Lignes Dimensions | 11.5 ‴ |
|---|---|
| Dimensions | 25.94 mm |
| Height | 6 mm |
| Further Measures | Mounting Diameter (Dm): 25.6mm |
| Power Reserve | 42 hours |
| Frequency | 18,000 vph |
| Jewels | 17 |
Complications and Specifications
| Shape | Round |
|---|---|
| Complications |
|
| Shock Protection | Incabloc |
| Regulator Type | Pinned Regulator (or Index Regulator) |
| Movement Type | Automatic |
| Rotor Type | Central Rotor |
| Escapement Type | Swiss Lever |
| Control Type | Balance Wheel |
| Winding Type | Automatic (Rotor-Driven) |
| Setting Type | Stem Set (Crown Pull) |
Additional Information
| Hand Sizes | 1.50 x 0.90 x 0.18mm |
|---|---|
| Hand Count | 3 |
| Country Of Manufacture | Switzerland |
| Notes | Remarks: 1951-1960 (Certina) selfwinding gear from beryllium bronze Other data: balance staff: U2207 stem: W2306 mainspring / battery: 1.25 x 9.5 x 0.10mm Mainspring: 1.300 x 10.000 x 0.100 x 340.000 mm |
| Signature | 1957: Certina, Swiss Made, 23 Jewels, Patents+; Incabloc (Certina 25-45) |
| Import Codes |
|
Compatible Parts
140 other caliber(s) share compatible parts with this caliber.
95 compatible part(s) available — Supporter feature.
Metadata
| Created At | Sep 15, 2023 |
|---|---|
| Updated At | May 26, 2026, 4:43:50 AM |
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