Technical Archive

Sinn
Instrument Watches 857.050— lug 22mm

Sinn Instrument Watches 857.050: 22mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Pilot's Watch EZM 7 S

Artisanal Note

"This model requires a precise 22mm lug width to preserve the original sartorial balance."

Technical Specifications

Sinn 857.050
Lug Width
22 mm

The essential strap measurement.

Browse 22mm straps →
Reference

857.050

Movement

ETA caliber 2893-2 Hours, Minutes, Seconds, Additional 24 Hour Hand (adjustable) | Date

The Heritage

The Sinn 857.050 Pilot's Watch EZM 7 S is a professional tool watch designed for pilots and international operators. It features a 43 mm stainless steel tegimented case, ETA Calibre 2893-2 movement with 24-hour hand and date window, and a 22 mm lug width. The design prioritizes functional readability and reliability, with high-contrast indices and hands, reflecting decades of feedback from professional crews in aviation and international operations.

FAQ

What is the lug width of the Sinn Instrument Watches 857.050?

The lug width of the Sinn 857.050 is 22 millimetres. This measurement represents the linear distance between the two fixing pins on either side of the case and determines compatibility with aftermarket straps. To verify correct measurement, position a digital calliper perpendicular to the pins: the value must be exactly 22mm to ensure fitting without play.

Which strap is most suitable for the Sinn 857.050?

The Sinn 857.050, being a professional instrument with a 43mm case, pairs exceptionally well with premium alligator straps for formal contexts, vegetable-tanned calf leather for vintage aesthetics that develop natural patina, and technical NATO or vulcanised rubber for operational environments. Your choice depends on context: professional-formal suggests alligator or calf, whilst operational-extreme indicates high-density NATO or rubber.

How do you change the strap on the Sinn 857.050?

The Sinn 857.050 strap is replaced by gently removing the spring bars from the lateral case pins. Use a spring bar tool or small flat screwdriver to compress the internal spring slightly, allowing the pin to exit its seat. After removing the previous strap, insert the pins into the new strap, aligning them with the lateral apertures, and press the bars until fully engaged. Verify the fastening by pulling gently.

Can I use an aftermarket strap compatible with the 857.050?

Yes, absolutely. The Sinn 857.050 with its 22-millimetre lug width is compatible with any quality aftermarket strap constructed for this same width. It is important to verify that the spring bars on the strap are intact and that the seating on the case pins is clean. Straps in full-grain leather, vegetable tanning, alligator, technical NATO and rubber are all usable without mechanical adaptation.

What is the average lifespan of a leather strap on the Sinn 857.050?

The lifespan of a leather strap depends on intensity of use, climate and material quality. A quality calf or alligator strap, worn daily in temperate climate, maintains structural and functional integrity for 2–3 years before showing obvious deterioration. Straps in full-grain leather or shell cordovan, thanks to their compactness, can last 4–5 years or more. In humid, tropical or mechanically stressful environments, lifespan is reduced. Proper drying after moisture exposure and periodic cleaning with neutral detergents significantly extend strap life.