Sinn 856 I B Tegimented

Sinn 856 money shot

This is a tale of two watches: the previously reviewed black-dial five-star Sinn 556 I and a blue-dial Sinn 856 I B Tegimented. Here in the U.S., sells the black beauty for $1380. The blue bomber runs $2300. That’s a big jump for what look like small differences. Welcome to Sinn City, where the devil’s in the details. Start with this . . .

The “B” stands for “Blau” (the dial color). The “I” stands for “Indexes” (compared to “A” for Arabic numerals). The A version has alphanumerics at the 12, 3, 6 and 9. The “I” version is the one, produced by Sinn for the Japanese and American markets. Lucky us! The new 856 is the only watch in the world more legible than the Mondaine Swiss Railways watch.

Which makes Sinn 856 I B Tegimented the world’s most legible timepiece. Hovering over the matte blue background, the stark white same-sized indices and hands pop like a needle-pierced balloon. Time-telling lives somewhere between automatic and subconscious. If you can’t tell the time at a glance with the 856 I you’re either analogue ignorant or legally blind.

Sinn comparison

I’m sure there’s some neurobiologist somewhere who can explain why the Sinn 856’s blue-and-white dial makes more of an impact on your retina than the Sinn 556’s black-and-white dial.

They might also be able to discern how much the 856’s larger dial (40mm vs. 38.5mm) and surface treatment (matte vs. gloss) plays into the recognition equation. Not to get too technical, winner winner chicken dinner.

Sinn 856 closeup

Date window positioning is another important variable. The 856 positions the black-on-blue date above the 4 o’clock index, whereas the 556 has the black-on-black date next to the 3.

I’m not the guy to explain why the 556’s symmetrical layout grabs more unnecessary attention than the 856’s off-center solution, but there it is. Or, if you’re checking the time, there it isn’t.

Sinn 856 I B Tegimented dot

There’s one more visual element differentiating the two timepieces: the tiny glossy dot on the 856’s dial, between the center and the 6. It only stands out when the light hits it from an oblique angle. Unless buyers RTFM or read this review, very few will know it’s there. That said, it’s a point of pride for those who do.

The dot signals the Sinn 856 I B Tegimented’s increased magnetic resistance. Nestled in a soft iron shell, it’s protected up to 80,000 A/m/1000 Gauss. Is this an issue? Sinn – and Rolex with their Milgauss model – would have you believe it is. Sinn’s take (read the extended version here):


Magnetism can cause dramatic swings in the timekeeping of a mechanical watch movement. People are often exposed to magnetic fields without even being aware – frequent high altitude flying, metal detectors, audio and video equipment, medical equipment and computer equipment can all cause problems with magnetism.

If you’re a medical professional hanging around an MRI machine or a commercial pilot flying the empty skies, the Sinn 856’s magnetic resistance might be a consideration. If you’re wearing a modern wristwatch flying to Vegas, tuning your Marantz receiver or sitting at your computer all day, I wouldn’t worry.

Sinn 856 copper sulphate capsule

A simple point that raises the watch collectors’ eternal debate: need vs. want. A question that also arises when considering the 856’s replaceable copper sulphate capsule.

The hidden feature protects the oils lubricating the movement and absorbs any humidity that manages to invade the sapphire crystal, preventing fogging. This the 556 I doesn’t have.

OMEGA Seamaster Planet Ocean

The capsule brings to mind the OMEGA Seamaster Planet Ocean‘s helium escape valve. You can round down to zero the number of owners who dive deep enough to need an HEV. Or below 200m (the Sinn’s water resistance rating).

The major benefit of Sinn’s capsule technology: it lengthens the recommended service interval to approximately seven to eight years, vs.  the 556’s recommended four to five year service interval.

By the same token, my Sinn 556 has never fogged. Nor am I worried about its movement losing lubrication. Sure, the copper sulphate capsule and horological Faraday Cage are nice to have. Reassuring features both. But is the anti-humidity, a lengthened service interval and anti-magnetic protection worth an extra grand?

But wait there’s more! The 856’s case is made of tegimented steel, sheltering a Chronometer Grade (but not certified) Sellita SW300-1 (Timegraph tested by TTAW to -1 seconds per day accuracy). Here’s Sinn’s rundown on the treated steel’s advantages:

Tegimented steel

Standard steel used by most watch companies has a hardness of between 200 and 240 HV. The Tegiment process produces a hardness of at least 1,200 Vickers which is five times harder than standard steel (and on some Sinn models up to nine times harder than standard steel).

The primary advantages to a Tegimented case are extreme resistance to scratches and other case abrasions, as well as increased resistance to corrosion. 

I’ve never scratched or dinged my 556i’s case. My watch is no safe queen. If I marred its surface, I swear I wouldn’t lose my shit; I’d consider it Wabi-sabi. BUT there are buyers who consider tegimentation the way to preserve their Sinn watch’s box-fresh finish into perpetuity. I get that desire, but again, what price OCD?

Sinn 856 department store

Strangely – or not if you’ve followed this blog – it’s the 856 I’s matte blue dial that tempts me to trade up and inspires me to recommend this watch without hesitation.

From certain angles the dial appears black. From every other angle it’s the most wondrous shade of blue, wandering towards navy. Then again, the black dial 556 I is the more distinctive, the more mysterious of the two.

Sinn 856 Bora Bora

If you’re looking for an incomparably legible watch with bells and whistles you’ll most likely never ring or blow, the 856 I B Tegimented is the bargain tool watch you’re looking for. If you can’t swing the extra dosh, black is beautiful. Either way, it’s a far, far better thing than you can get for the same price elsewhere.


Case diameter: 40mm
Case thickness: 11mm
Case lug width: 20mm
Lug to lug: 47.5mm
Weight: 3 ounces
Water resistance: 200m
Case back: Solid
Case metal: Tegimented hardened steel
Front crystal: Sapphire
Inert gas: Filled
Copper sulphate: Capsule
Antimagnetic: 80,000 A/m
Movement: Top Grade ETA 2824
Manufacturer’s limited warranty: 3 years

RATINGS (out of five stars):

Design * * * * *
Minimalism über alles.

Legibility * * * * *
The world’s most legible wristwatch.

Comfort * * * * *
The leather strap variant (reviewed here) requires some breaking-in, but once it is it’s like a second skin.

Overall * * * * *
Thanks to a matte blue dial, the best just got better. Don’t know if you need all the bells and whistles, but that’s the price of admission.


TTAW is a fully independent watch website
Watchbuys.comloaned us the watch for review.
No further considerations were provided.


  1. I love Sinn because they make IWC look like an utter joke, doing everything the IWC brand claims to represent, but better, at a lower price.

    That said, I will throw out the Tissot T127.407.11.041.00 as an alternative to this watch ($775 retail, low $600s grey). Deep blue dial with the same case diameter and thickness. What this watch achieves with a Faraday cage and copper sulphate capsule, the Tissot achieves with a silicon balance spring.

    The depth rating on the Tissot is 100M lower, and it lacks the tegimented treatment.

    1. A lot of watch brands are like this. There’s a definite difference up to about 1,500, then it’s just “finishing”.

  2. Love German watch brands. So do Swiss watch brands who have bought a German brand or two.

    The black is intense. Do you get metaphysical staring at that dial for hours? I get the point about the price jump but it would be the Philosophical Blue for me. The wrist wants what the wrist wants.

    1. Mr Farrago,

      You say “The ‘B’ in Sinn 856 I B stands for ‘plain’ indices rather than alphanumerics.”

      Actually, the “B” stands for “Blue” (or “Blau” if you like), the color of the dial. (Incidentally, Black dials don’t get a letter.)

      The “I” stands for “Indexes”, compared to “A” for “Arabics”, as in Arabic numerals. “A” does not stand for “Alphanumerics”, as there are no watches with letters for the hour positions.

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