The Sinn 757 UTC Series has become one of the best selling in the Sinn Pilot's Series of watches.
On a frequent basis we receive client praise for Sinn's "Tegiment" (hardening) technology, and have heard quite a few stories of watch cases scraped against metal railings, car doors, metal desks, and other more interesting objects with little to no damage to the case.
Standard steel used by most watch companies has a hardness of between 200 and 240 HV (Hardness Vickers is a common scale used to measure material hardness). The Tegiment layer has a hardness of 1,200 Vickers which is up to five times harder than standard steel.
The Tegiment layer is not a coating consisting of a foreign material, instead the steel itself that has been hardened using a special engineering process that creates a hardened barrier. The base material is a type of stainless steel also used for surgical implants, and the stainless steel resistance to corrosion is even further improved by the Tegiment hardening process.
Another Sinn engineering feat is the creation of a bezel that is secured by screws. The inlaid aluminum ring featuring numerals and markers is anodized black for optimal legibility, while the triangle reference marker at 12 is applied with special paint for visibility.
What also makes this watch special is its extreme protection from magnetic fields. The case design and inner lining consist of a special iron core making this watch resistant to the effects of magnetism.
The case features a copper sulphate capsule which reacts with moisture to diffuse and absorb humidity in the watch. This capsule may be viewed through a porthole in the left lug, and over time will turn a deep blue as humidity is absorbed. This technology not only provides a more stable environment for the movement, but also helps to prevent fogging of the crystal when going from hot to cold environments or from humid to non-humid conditions (such air conditioned buildings).
This watch has a second time zone displayed by a skeleton yellow hour hand. The second time zone can be set directly through the second position of the crown and also can be hidden under the main hour hand when not in use.
Sand-blasted stainless steel case with solid back. Dial is matte black with Arabic numerals and offset date display at 4. The design and layout of this watch make it extremely easy to read in virtually all light conditions.
Sapphire crystal with luminous hands, hour markers and the 12. Watch is water resistant to 20 ATM. Watch is fitted with a Tegimented steel bracelet with hex screws and solid end links.