Why Are Some Watches So Lightweight? (for no good reason)

First off, that movement is skeletonized and there is quite a bit of empty space in that huge (46mm?) casing. Also, while the "case" may be stainless steel (the outer rings that connect), the bezel/dial elements holding the movement may be alloy or brass. It probably also doesn't help that the watch is a piece of junk.

talking about skeletonized done improperly 😂

Just for fun, I've calculated some stuff

316L is a grade of stainless steel, the alloy is made up of Fe, (16-18%) Cr, (10-12%) Ni, (2-3%) Mo, (0-2%) Mn and some other elements that make up a further >1% of the alloy. For our convenience, we can leave out the 1% of other stuff and work with the main elements. 
If we take the density of Fe as our baseline, for the hypothetical low quality 316L stainless we can add the highest percentage of lighter elements (Cr, Mn) and the lowest percentage of heavier elements (Ni, Mo). For the hypothetical high quality 316L stainless, we can do the opposite.
After some calculations, we get a density for the low quality of 7.898g/cm³, compared to a density for high quality of 7.971g/cm³. 
So if our hypothetical high quality watch had 50.0g of 316L stainless steel in it, the same watch with the hypothetical low quality 316L would have 49.5g in it.

In conclusion, I doubt you'd feel the weight difference if both high and low quality watches were constructed in the same way. More than likely there's just less material being used combined with a soft, lower quality steel, making for a cheaper feeling watch.

Thank you for coming to my TEDtalk

For those wondering, this watch is 72 grams 😂

Probably because they cut out the middle man, shaved off all that extra weight.

Maybe the only steel bits are in the movement.

The detail on the outside of the case looks like the case was cast and not much machining went on, just plating of some sort. Whether the base material is plastic or some alloy remains to be seen.

The batons and the ring supporting the movement also look cast, not many sharp edges from machining there. Moving the batons out past the movement at least makes the whole thing more legible at the cost of overall diameter. Too many heavily skeletonised watches don't have enough contrast between the hands, movement and whatever batons there might be, relying the viewer's depth perception.

I can see this watch having some enterainment value as long as it keeps reasonable time.

I think punching below it’s weight is the correct summary. I do feel these kind of watches are in some ways interesting odd birds. Your’s took someone’s time to design, then it was executed as cheaply as possible I think. I got a Stauer as a gift from a very caring daughter some years ago (and it remains in my collection for that reason!) As you’ll see below, its roughly the size and shape of a ping pong ball, and not in a good way. It has hands with a complicated shape to fit in the bowl of the watch and a very tiny automatic movement. It’s almost impossible to figure out the time. When looking at it, I think ‘someone actually designed this’. Indeed wonders will never cease. Enjoy your odd bird, hope it has a good story. 

I believe it was the philosopher Ian Malcolm who said, "Are they heavy? Then they're expensive. Put them back." 

We've gotta shake this misplaced 90s notion that heavy=quality/expensive. Titanium is lighter and more expensive. The Bulova Octos are thinner, lighter, technologically mind-blowing, and super expensive. 

You know, I bought a Stuhrling bridge skeleton watch a number of years ago. I was curious about the company. The movement shot craps within 6 months. I don't know if I accidentally damaged it or not, but it stopped working altogether. I was going to buy another one when I saw the same movement on AliExpress. 😢

I think you’re mistaken, the lawyer said that. Great line nevertheless! 

Zooming in on the photo, the ring that contains the minute track looks like it could be chromed plastic, which could explain part of it. Plus, perhaps the lugs aren't really solid?

Ah, the ”bloodsucking lawyer!”

https://perrinwatchparts.com/collections/chinese-mechanical-watch-movements/products/chinese_mechanical_watch_movement_2660s

that has one of the cheapest movements on the market they sell in $30.00 watches on Aliexpress complete with dirt and fingerprints but no lubrication.

Regardless of weight, I really don't like the look of that watch. Reminds me of an ostentatious cousin of the Swatch Jellyfish 😂 

I do agree, even with my earlier funny (?) post. I have a number of quality titanium watches from Omega, GS and Ball. Love them and they get a lot of wrist time. 

Well I’ll be just plain gobsmacked. It don‘t look right…put it up against the wall! 

So we agree then; everyone loves this watch. 

One of my first watches was a stuhrling, I regret it so much, felt so light like it was made of chrome painted cheap plastic, didn't know better back then.

I think a number of factors are probably at play here. 

Firstly poor construction materials with slightly less density, cheap small auto movement, a large portion is skeletonized and a thin leather band. 

Secondly I think perception has played a part, at 46mm its clearly a very large watch and does it just feel lighter than your mind tells you a 46mm watch should feel based on any number of the points above. 

As has been shown above the weight is not too dissimilar to other "quality" pieces all be it they're smaller. 

My measurement was with the strap and with a case much larger than those two you show. 42mm x 14mm thick, with a rear crystal too. I think yours are safe 😉

I was wondering why there isn't much talk of Stuhrling watches out there. Looking forward to the full review.

This one is an automatic, any idea if there's an automatic version of the one you listed? Or do you reckon they shoehorned on an automatic rotor? Struggling to find it online. I'll post shortly with photos of the rear too

I...

As a veteran of the TV watch wars, I promise to be nice and type in no point here.

Which should tell you everything you need to know.

This watch is just so damn ugly...

Just one thing to add: Copper and its alloys (brass, bronze) are heavier than steel. They're also a bit more expensive. However, they're much easier to work on, bringing the manufacturing costs radically down.

If something doesn't weigh what it should, it's got plastic, maybe aluminium, or possibly just air in it.

Have you tested the key to the door of your house. If it gets scratched, it's probably aluminum or another material, do the same with all the watches.