The HMAC Long Read

Do you like riddles?

Today we will illuminate the part of the watch you see the least but use the most.

What is it?.....the clasp.

Specifically, we are going to delve into the story behind our hi-tech HMAC (HORAGE Micro Adjustable Clasp). This story and the end-result is a case of, the more you learn the more your head hurts.

So….. buckle up (sorry) and get ready for a wild ride!

Before we look at our HORAGE solution, let’s take a step back and try and define what characteristics a good buckle should achieve – both from the perspective of the user but also the brand: you might not 100% agree with the sequence of these ‘must haves’ but we can live with that.

Here’s our Clasp Top 10:

1.        Secure

2.        Easy & intuitive to use

3.        Comfortable to wear

4.        Durable & dependable

5.        Great design/aesthetics

6.        Thin (low build height)

7.        Widest possible range of adjustment

8.        Lowest possible number of parts (and left-right specific parts)

9.        Compact (shortest length of hinge plates)

10.  Easy to assemble

Note that for us at HORAGE cost is not present in this list, notwithstanding the last 2 points, where it does play a role. As you know, we like to be über-transparent at HORAGE. Whilst we designed and engineered the HMAC it isn’t manufactured in-house. We work with a trusted partner: a global leader in clasps and bracelets. Each HMAC costs HORAGE more than many brands pay for their off-the-shelf, Swiss made calibres. The HMAC is 100% made of Stainless Steel for Supersede and DecaFlux models whilst Autark adds a Titanium Buckle cover.

When we set off on project HMAC our engineers also worked on three other reference points: (1) Keep the best features from our existing deployment buckle design used on the Array (2) Improve on the Array design and (3) Build a solution, which is better the very best existing clasp….available from you-know-who.

Did we achieve our aims? Let’s get into the nitty gritty.

01. Security – not like a bunker deep inside the Alps – security means the clasp retaining mechanism cannot accidentally be opened, no matter what leverage your arm or external factors apply. Our design requires both buttons to be pressed simultaneously with a specific force, for the cover to be opened. Mission accomplished.

02. Easy to use – some buckle/clasp designs require a securing latch to be deployed, which fits over the outer plate. We wanted a simpler arrangement. When pressure is applied to the cover the closing mechanism engages with an audible click, the wearer is given consistent tactile feedback and your amazing muscle memory quickly stores this information in: This Brain>Watches (Clasp:)

Using the micro adjust feature is also quick and easy. When the HMAC is open the cut-out space in the “Sliding Block” allows your finger to easily locate and exert the required pressure to slide the buckle into the fully open position. When worn on the wrist a finger and thumb squeeze initiate the micro adjustment with a distinct “click” indicating each 1mm change. Two down, eight to go

03. Comfortable to wear: this one is tricky as every human wrist is unique in shape and size. And even worse: comfort is highly subjective…some humans choose to explore polar ice caps and deserts for ‘fun’. For us as designers, comfort is achieved through a carefully considered shape and dimensions. The radius, length and width of the lower buckle is critical. Edges need to be bevelled at exactly the right angle, finishing executed to highest standards. Balancing aesthetics and functionality are key, along with less obvious factors such as the interaction (e.g. rotation, lateral play) of the bracelet links and the clasp hinges. We hit the sweet spot: what do you think?

04. Durable & dependable – aren’t these the same, you might ask? Certainly, they are closely related and mutually dependent on another. Both are the result of clever design and precision manufacturing. From the very first design brief we were adamant that the HMAC should only use leaf springs. Spiral springs are too delicate. Two independent springs are used – one for the micro adjust and the other to pre-load the closing buttons. One generously dimensioned fastener holds the assembly together. Clamping forces are not transferred to the hinge plates, pins or screw. Conclusion: we nailed it

05. Good lookin’? Again, a highly subjective topic, and with the clasp 95% hidden under your arm does it even matter? Of course it matters. We want to be as proud of our product as you are happy with it. A well-considered mix of brushed and polished elements lay the foundations. HORAGE is not an ostentatious, glitzy, brash company: We’d rather let our engineering do the talking. Thus, our brand presence is subtle and understated, etched into the outer buckle as the mosaic “H” and hidden to the outside world in its full glory two layers down. We don’t think logos need kidnapping to form part of a blinged out mechanical structure….maybe we’re just a little...different. Synopsis: we’ll let you decide. 

06. Thin. Making a complex structure with multiple folding planes strong and torsion resistant is straightforward. Making it all of the above and slim - that is a big deal. To this day, lead engineer Marcus can quote verbatim the feedback he received from Tzu upon presenting his first design: “It’s good: now make it slimmer.” Somewhat dejected, Marcus went back to the proverbial drawing board. Without five layers the mechanical function could not be realised. The material dimensions were already at the limit…..What if each folding element could cleanly recess inside the preceding layer? It was this lightbulb moment that allowed us to build a clasp with an astonishing thickness of 5.9mm. Score: industry leading

07. Wide adjustment range. Sometimes less is more, but for this criterion more is more. More range normally means longer hinge parts and an associated decrease in rigidity. Either of these traits would cross our self-imposed red lines, setting off loud sirens and flashing red lights at HORAGE HQ. Look inside the micro adjust mechanism and you can see that not a single mm of space is unused or wasted. The trailing edge of bracelet is always supported by the buckle cover preventing undesirable twisting whilst the spring- loaded sliding block neatly interfaces with the so-called “Fixed tooth” – both parts locking and bracing one another in the fully closed position. A full 10mm of adjustment are achieved: this is zero fat engineering. Teachers’ marks: 10/10

08. Lowest number of components. Make a complex, precision assembly with zero left-right specific parts and a low overall quantity of bits. Is this a concession to cost? No: our HMAC is significantly more expensive than widely available off-the-shelf systems, which get the job done. But less parts (and directional parts) do support higher reliability and improved functionality. Including the bracelet end links we managed to achieve the HMAC with 18 unique parts. Don’t forget, our partner must factor in over 350 unique dimensions and measurements when producing the HMAC, the 2D drawing document has 16 pages. The faces of the teeth necessitated us building a new CNC cutting tool for our partner. As you can see, simplicity is a flexible concept. Synopsis: precision simplicity

09. Compact. Didn’t we already include this? No, build height and build length are two different variables, and this is a Top 10, not a Top 9! The same, but different issues persist. A tightrope walk of function, simplicity, precision and size. Anybody can build a 7 litre V8 with horsepower, but achieving the same result with an air-cooled 4-cylinder boxer block which 2 guys can lift by hand: that’s engineering art. The longest latch part of the HMAC is 4.85x19.1mm allowing it to comfortably disappear behind the slenderest of wrists. Verdict: see (06)

10. Easy to assemble. Let’s be clear: 99% of us would struggle to assemble the HMAC: but with no tiny spiral springs, no micro fasteners and zero LH/RH parts it is comparatively straightforward to put together (for a watchmaker). This is an oft-overlooked criteria as engineers rarely have to get their hands dirty assembling the stuff they have created. Not so at HORAGE! This 360° product immersion is a critical part of our company culture. Epilogue: a walk in the park for nimble hands, for normal humans- don’t give up your day job

Who’d have thought that a simple folding latch mechanism could be hiding so much tech!?

Don’t worry, we won’t be writing a 5-page thesis on military style fabric straps at any time soon.

What are your thoughts on the HMAC?

How does it compare to other bracelet clasps you use?

Hit us in the comments