Series 31
The pocket watch movement that has been redesigned to feature an indirect central second hand makes this watch an elegant choice. A key feature of the movement remains the secret of the wearer – the second stop.
To precisely set the time of a wrist watch most movements are equipped with a second stop – when the crown is wound, the second hand doesn’t move. The seconds zeroing is a much rarer design.
When the crown is wound, the second hand continues to run until it reaches “60” and then it automatically stops – thus it is possible to use a time signal to set the watch to the second.
Model Overview Series 31
31.HS-12.1
Bezel
fixed bezel
Case
stainless steel polished, case sides in satin finish
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring, swan neck micrometer
31.HS-12.2
Bezel
fixed bezel
Case
stainless steel polished, case sides in satin finish
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring
31.HS-14.2
Bezel
fixed sandblasted bezel
Case
stainless steel bead-blasted
Dial and Hands
deep black dial, hands made in steel
Special features
Nivarox hairspring
Technical details
Movement
- Calibre HS 81
- Base: UNITAS 6497 Lépine. Modified as per a construction by Helmut Sinn
- indirect center second
- second stop at 60 when crown is pulled
- 18 jewels
- 18000 vibrations per hour; 2.5 Hz.
- Movement diameter 16 1/2''' (36,6 mm)
- Incabloc shock protection
- Glucydur balance
- Nivarox hairspring
- Movement decorated with Geneva Stripes , blued screw hads, crown wheel and ratchet wheel with solar finish
- Power reserve approx. 40 hours
Functions
- Hours, minutes, indirect center second
- Second stop at 60 when crown is pulled
Case
- Case made of stainless steel, polished
- sapphire crystal glass, anti-reflective on the interior
- screwed back with crystal glass
- Pressure resistant up to 10 bar
Dimensions and Weight
- Case diameter: 41.9 mm
- Case thickness: 13.7 mm
- Band lug width: 22 mm
- Weight without strap: 71 Gramm
Straps 22 mm
Leather Strap Arizona
Black Cowhide with alligator embossing.
Available with a pin or folding clasp.
| Cases 22 mm | Type 42 | Type 31 |
|---|---|---|
| ideal wrist circumference in mm | 192,3 mm | 191 mm |
| ideal wrist circumference in inch | 7.6 in | 7.5 in |
| max. wrist circumference in mm | 212,3 mm | 211 mm |
| max. wrist circumference in inch | 8.4 in | 8.3 in |
| min. wrist circumference in mm | 172,3 mm | 171 mm |
| min. wrist circumference in inch | 6.8 in | 6.7 in |
Wrist circumference specifications are approx. values and depend on the individual wearing habits.
Leather Strap Monza
Dull finished calf leather with contrast stitching, BR-padded
Available with a pin or folding clasp.
| Cases 22 mm | Type 42 | Type 31 |
|---|---|---|
| ideal wrist circumference in mm | 187,3 mm | 186 mm |
| ideal wrist circumference in inch | 7.4 in | 7.3 in |
| max. wrist circumference in mm | 207,3 mm | 206 mm |
| max. wrist circumference in inch | 8.2 in | 8.1 in |
| min. wrist circumference in mm | 169,3 mm | 168 mm |
| min. wrist circumference in inch | 6.7 in | 6.6 in |
Wrist circumference specifications are approx. values and depend on the individual wearing habits.
Leather Strap Starfighter Pilot
Black leather strap made of intensely grained cow hide with a subtle contrast stitching.
Available with a pin or folding clasp.
| Cases 22 mm | Type 42 | Type 31 |
|---|---|---|
| ideal wrist circumference in mm | 195,3 mm | 194 mm |
| ideal wrist circumference in inch | 7.7 in | 7.6 in |
| max. wrist circumference in mm | 213,3 mm | 212 mm |
| max. wrist circumference in inch | 8.4 in | 8.3 in |
| min. wrist circumference in mm | 176,3 mm | 175 mm |
| min. wrist circumference in inch | 6.9 in | 6.9 in |
Wrist circumference specifications are approx. values and depend on the individual wearing habits.
Leather Strap Vintage Black
High-quality leather strap with red stitching, at the tip of the strap and at lug ends
Leather uppers, matte; Underside leather both cowhide. The thickness of the strap is approx. 3,3 mm.
Available with a pin or folding clasp.
| Cases 22 mm | Type 42 | Type 31 |
|---|---|---|
| ideal wrist circumference in mm | 200,3 mm | 199 mm |
| ideal wrist circumference in inch | 7.9 in | 7.8 in |
| max. wrist circumference in mm | 215,3 mm | 214 mm |
| max. wrist circumference in inch | 8.5 in | 8.4 in |
| min. wrist circumference in mm | 181,3 mm | 180 mm |
| min. wrist circumference in inch | 7.1 in | 7.1 in |
Wrist circumference specifications are approx. values and depend on the individual wearing habits.
Leather Strap Antique
Pull up leather with laquered edging and colored stitch.
Available with a pin or folding clasp.
| Cases 22 mm | Type 42 | Type 31 |
|---|---|---|
| ideal wrist circumference in mm | 193,3 mm | 192 mm |
| ideal wrist circumference in inch | 7.6 in | 7.6 in |
| max. wrist circumference in mm | 213,3 mm | 212 mm |
| max. wrist circumference in inch | 8.4 in | 8.3 in |
| min. wrist circumference in mm | 171,3 mm | 170 mm |
| min. wrist circumference in inch | 6.7 in | 6.7 in |
Wrist circumference specifications are approx. values and depend on the individual wearing habits.
Rubber Strap Glatt
Black rubber strap, smooth surface, incl. a laser engraved folding-clasp satinated or bead-blasted.
Available with a pin or folding clasp.