So these are indeed British after all. Can you help me determine their age?

These were originally listed as Indian. The key looks weird.  The key looks like the original key's head snapped off and someone did a repair job by connecting a new brass collar and head. The "wings" shape is to allow it to turn and not smack into the hinge. The key works flawlessly and smoothly.

They are a bit like my late 1800s Hiatt 104 but with less heft, with the nice more rounded shackles and clevis bulges. But these are an actual back strap. (higher resolution better images in a post farther down). They are stamped HIATT, HARD and have a 0 stamped on them near the HIATT branding. See the later images a few posts down. I'd love to know roughly how old these are.

There were English made cuffs stamped with the retailers name in India, but not made in India. The one you show is almost certainly English. 

PaulJDavies wrote: ↑

Feb 16, 2024

There were English made cuffs stamped with the retailers name in India, but not made in India. The one you show is almost certainly English. 

Thanks. That key is a bit weird though. The seller said one side opens perfectly but the other side you have to pull on the key a bit. When I get the cuffs I will do my usual de-gunking and hopefully it will function. I am hoping it will be a proper back-strap. I will post good images after I get them in the hopes people can help me identify the approximate age and if a manufacturer stamp is missing or worn, perhaps which is the most likely manufacturer.

It is a real backstrap and an old one, I would guess an early Hiatt or Froggatt or Nichols. I can also see the the endcap is pinned which is also a sign of an early cuffs. The key looks like an adapted clock key.

If it is indeed a true back strap that will be my first and make me very happy! I have a JG British military pair from the 50s which has all the markings ground off which has a false back strap. I do like the false one, I feel like it would probably be stronger and more durable than the more common hinge pins. But I've wanted a true back strap for a long time.

I wondered if the key was perhaps a repair job on a key who's head was snapped off.

I have received them. I love them so much! If these higher resolution images help, is there an approximate age these could be, given what you see here? Serial number says 0.

The key works flawlessly. I have tried every single other key I have and no other key works properly. One which works in my late 1800s pair gets 4 twists and stops dead but would serve as an emergency release (to be pulled) if my main key breaks and somehow someone gets stuck in them.

The plugs are also pinned but weirdly they are pinned in 3 places. A pin in both sides and the bottom. There's no pin in the side facing the shackle. 3 pins!?! That is really something I have never seen.

These are really nice. I'll be really interested in your thoughts on these.

Every cuff that I have that is pinned has three. I believe it’s the norm. Congratulations on a beautiful cuff. Ron J

When pins are used to secure the cap, three pins is the norm. Ron is right on !

And here's a video overview of them:

I have seen Mr Handcuff's pair of HIATT M&C from 1882 but the backstrap on his looks more chunky, which it seems British military handcuffs with real or false backstraps seemed to be. His say HIATT & Co whereas mine just say HIATT. Not sure if that helps in dating? I believe by the late 1800s they had already moved to the more familiar and plentiful pinned hinge style, since my others were dated to late 1800s and the 1907 catalogue shows no backstrap models. But other than that I can't tell how far back my pair may go. Hopefully some people in the know can offer estimates to get a good idea? So far I have been given a possible range of 1850 and 1880.

I have compared mine to every Hiatt backstrap on the handcuffs.org gallery. The back straps seem chunky compared to mine and the tongue that's rolled over, each and every pair extends farther back than mine. Here's an example from the site of one which is 1850s:
You can see the tongue that is pressed over extends almost to the same edge where the clevis is inserted. It extends back far and is chunky. My pair are not that chunky and the tongue does not extend back that far, maybe a tiny bit over half way. Does this indicate anything?