Instrumentenuhr

Serie 31

The instrument watch

Our Serie 31 is an instrumental manual winding watch with an indirect central second hand. The sapphire crystal directs the focus to the very readable face

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Clasp

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

Modell 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

Modell 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

Modell 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
  • Triovis precision adjustment system
  • 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: 12,7 mm
  • Band lug width: 22 mm
  • Weight without strap: 71 Gramm

Straps for Series 31

Arizona

Leather Strap Arizona

Black Cowhide with alligator embossing, pin-clasp
folding-clasp available

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 191 mm / 7.5 inch 211 mm / 8.3 inch 171 mm / 6.7 inch

Colour variants

light brown
dark blue

Montana

Leather Strap Montana

Armband Montana schwarz

Soft nappa leather in black, pin clasp
folding-clasp available

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 193 mm / 7.6 inch 212 mm / 8.3 inch 172 mm / 6.7 inch

Colour variant

Armband Montana Hellbraun
light brown

Kroko

Leather Strap Kroko

Leather Strap Kroko in black

Black alligator leather, pin-clasp

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 205 mm / 8 inch 226 mm / 8.9 inch 178 mm / 7 inch

Colour variants

Leather Strap Kroko in dark brown
dark brown

Rustikal

Leather Strap Rustikal

Leather Strap Rustikal black

Black cowhide with alligator embossing, cushioned, contrasting seam white, pin-clasp

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 201 mm / 7.9 inch 218 mm / 8.6 inch 182 mm / 7.2 inch

Other Leather Straps

Leather Strap Ozean

Leather Strap Ozean

Black shark fish leather with pin-clasp,
folding-clasp optionally available

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 194 mm / 7.6 inch 212 mm / 8.3 inch 174 mm / 6.9 inch

Leather Strap Waterproof

Leather Strap Waterproof

Black waterproof cowhide with pin-clasp,
folding-clasp optionally available

Wrist size – strap length on Series 31

All wrist sizes are ca. dimensions, depending on your wearing habits
  middle hole outer hole inner hole
strap length incl. watch 194 mm / 7.6 inch 212 mm / 8.3 inch 173 mm / 6.8 inch

Rubber Straps

Rubber Strap Kroko

Rubber Strap Kroko

Black rubber with alligator embossing, contrasting seam white, pin-clasp

Rubber Strap Glatt

Rubber Strap Glatt

Black rubber strap with a smooth surface, folding-clasp

Clasp overview

Pin Clasps

Stainless steel pin clasps

Pin Clasp polished
Pin Clasp bead-blasted
Pin Clasp PVD coated

Folding Clasps

Stainless steel folding clasps

Folding Clasp polished
Folding Clasp bead-blasted