AHO 555

AHO 555 | 17jewels.info - The Movement Archive

AHO 555


A rare specimen of the elongated 5 1/4 ligne form movements is the AHO 555 from Pforzheim im Germany, which was made around 1960.

AHO 555: base plate

base plate

It is impeccably crafted, even using a cap jewel on the upper escape wheel bearing and a bearing jewel for the upper minute wheel bearing, in reference to the very important and effective advertising number of 17 stones.

AHO 555: gear train

gear train

The AHO 555 uses the conventional gear train with directly driven center minute wheel, followed by the really tiny third- and seconds wheel and finally a rather large and very filigree escape wheel.

Due to the limited space, which this kind of movement offers, the dial side bearing for the seconds wheel is located half-high, above the escape wheel.

AHO 555: side view of the gear train

side view of the gear train

The ADO 555 uses a swiss pallet lever escapement and a not yet shock protected balance wheel with screws (in 1960 this was no more up to date), which beats contemporarily slow with 18000 A/h. The adjustment can be made on the hairspring key only.

AHO 555: AHO 555: Dial side

AHO 555: Dial side

On the dial side, the AHO hallmark is easy to see, everything else is pretty unspectacular. The yoke winding system, which is used here, is standard.

In the lab

This movement came without case into the archive and got a simple service.

Timegrapher result

For a well used, about sixty year old movement, the rares are acceptable, but indicate the need for a real service or spare parts, e.g. a new mainspring. The almost non present beat error is impressive, since the hairspring stud is fixed and the beat error cannot be adjusted.

horizontal positions
dial up -0 s/d 206° 0.0ms
dial down +8 s/d 200° 0.0ms
vertical positions
crown right (12 up) +35 s/d 152° 0.3ms
crown up (3 up) +30 s/d 156° 0.1ms
crown left (6 up) -55 s/d 164° 0.4ms
crown down (9 up) -45 s/d 160° 0.1ms

Technical data

Size:5 1/4''' (measured: 12,8 x 19,2mm)
Number of jewels:17
Escapement:Pallet lever
Balance types: monometallic screw balance (two legs)
Shock protection(s): none
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:no
Adjust mechanism:Hairspring key
  • lever
  • escape wheel, seconds wheel, third wheel, center minute wheel
  • mainspring barrel
Construction type:solid construction
Winding mechanism:yoke winding system
Setting lever spring:3 hole(s)
References: Feilner: Bl.66 6383
Flume: K2 1962 28
Mentioning in literature (years): 1960
Inventory number:22071

Usage gallery

AHO 555: Goldwyn ladies' watch  (case missing)

Goldwyn ladies' watch (case missing)

Other movements from AHO