Orient Non-Scratch and Super-hard Stainless Steel

In 1962 Rado presented the "Diastar", the world's first scratch-resistant watch. The concept took a few years to gain popularity, but when it has, it pushed other watchmakers to follow. Orient was one of the brands that set out to deliver a scratch resistant watch. But before we dive into this piece of history, let's first understand what scratch resistance is.

Hardness – measured in HV (Vickers Hardness), inversely corresponds to the depth of a scratch left by a pyramid-shaped indenter, when pressed at a given force against the surface of the material. The deeper the dent, the lower the hardness; the higher the HV value, the more scratch-resistant the material.

The hardness of typical 316L stainless steel, as used on most watches is 150-200 HV – depending on the specific compound and treatment. It generally contains iron, chromium (16-18%), nickel (10-12%), and molybdenum (2-3%). Rolex's famed 904L steel boasts similar hardness – it retains its shine thanks to better corrosion resistance, not scratch-resistance.

HY-80 aka "submarine steel", used for instance by Sinn, achieves 300 HV (Sinn actually further hardens it with surface treatment). Damasko manages to reach 800 HV by a special treatment, removing nickel and adding carbon and nitrogen.

It is also possible to coat or harden just the surface of the steel, maintaining the ability of the core of the material to sustain blows without breaking. Such surface treatment can achieve well over 1000 HV, which is ceramic territory; however, as this is skin deep, it would be a good protection against regular scratches but leaves the metal vulnerables to deeper indentations.

Like Rado with the Diastar, Orient used Tungsten Carbide for its "non-scratch" watches. This material is extremely hard, measuring 2600 HV, and is generally considered the hardest material that can be used in the jewelry and watchmaking industry, excluding gemstones of course.

The brand produced a few non-scratch watches in the late 1960s, mainly Deluxe and Chronoace models. These typically cost significantly more than similar stainless steel models, as much as doubling their price.

Many Orient Nonscratch watches were characterized by a hexagonally-shaped caseback – reminiscent of the hexagonal structure of Tungsten Carbide crystal. Ironically the case-backs were made of steel.

Tungsten Carbide had its limitations though: it is almost twice the density, and hence the weight per given shape, than steel. It is more brittle than steel, which is serious consideration: most people would rather have their watch get scratched when hitting the door knob than break.

Tungsten Carbide is also very hard to machine, and particularly tough to mold into complex shapes. Which is why all of the Orient Non-Scratch watches you'll find are either just a circular, lugless case or a similarly featureless and equally lugless barrel.

Now, there was nothing wrong with these case shapes, and many of these were absolutely pretty, some with lovely "Mexican" or other colorful dials. But, the cost and complexity of manufacturing them was considerable, and prevented the use of more interesting case shapes, surface brushing, rotating bezels etc.

So, like many other watchmakers, Orient ditched the carbide option in favor of hardening stainless steel.

Orient's "SSS" or Super-hard Stainless Steel claimed a surface hardness 1000 HV, a very respectable value in the 1970s. With this material, Orient could produce more elaborate case shapes, and maintain similar machining to those used with regular steel.

Super-hard Stainless Steel was used initially with Chronoace watches, and later in the 1970s with some caliber 46-based models. Indeed the use of steel enabled Orient to produce a greater variety of case designs with greater geometric complexity.

Another advantage for the SSS approach was it enabled a more visually seamless integration of the bracelet with the watch case. As carbides could not be used to produce bracelets, the contrast between the relatively dull steel and the bright sheen of the tungsten case might have seemed odd. That said – there's no denying that even as new, SSS cases could not match the mirror-smooth polish of the Nonscratch cases.

Towards the 1980s, "SSS" models too gradually disappeared from Orient's product lines. Today, even those Super-hard cases would show signs of aging; however, vintage Orient Non-scratch watches can often be found with their tungsten carbide cases sparkling like new.

Pictures that appear on this post were taken from old Orient catalogs, online sale ads, and Wikimedia.