Hiatt Darby 104 Key Dimensions?

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

Is your man...

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

If my memory serves me well, I think it is 1/4 inch whitworth.

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

have you ever thought about taking a WAX impression..... joe

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

It appears this is slightly smaller than 1/4 inch. A 1/4 bolt is too big to screw into the key. (it won't go in far enough for even the first thread to catch). I would estimate the outside diameter to be around .220 or .230. It is certainly larger than 3/16 inch.

How would you make a wax impression? Do you pour melted wax in the key and try to unscrew it when the wax hardens? I would think it would be stuck and you would have to melt the wax to get it to come out. ????

Thanks again, Steve

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

Ever thought of asking Ian McColl since he has made alot of those keys?

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

Based on the advice received, I wrote to Ian McColl asking for information. He responded that the most darby handcuffs were made with 'bastard ' threads, so prisons couldn't easily make their own keys. So, it looks like commercial taps in the correct sizes are not available.

In order to make his own keys, Ian has made taps to the various thread sizes used in most common darby handcuffs.

I have a metal lathe and may try to make some samples screws in various diameters and threads per inch to see if I can create a screw that will fit one of my Darby keys. Once I know what thread size I have, I will consider what it would take to have a tap made.

Thanks again for the help.

Steve

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

Hi Does someone have Ian McColls email address Many thanks Mike

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

I am looking for 2 replacement keys and am willing to pay going price can anyone assist please Steve can you help?

Does anyone know the correct size thread for the the Hiatt Darby 104 handcuffs? I have several pair of these cuffs and the keys interchange and work in all of them, but I can't identitfy the thread size. I also have one of the "die cast" Darby keys from a Hiatt Thompson Darby 104 and this key also works in my older iron model 104 Hiatt Darby cuffs that are marked "British Made". I would like to make some extra steel keys and need to know what size hole to drill and what size tap is appropriate to cut the threads for used with these cuffs. Is this some standard British thread size or did Hiatt create their own taps to make these keys?

Thoughts? Thanks

I ended up making several replacement keys for Hiatt 104 Darby cuffs. I made a tap that is 7/32 diameter by 18 Teeth per inch and this works well in several pair of Hiatt 104 cuffs that I have. I have made keys in both steel and brass with my tap.

Not all cuffs have the same type key and I am not sure this would work for you. I did send a pair of Keyser Adjustable Dabry cuffs to Ian McColl in Australia and he made up a key that is 14 TPI for that cuff and this was different from other Keyser darby keys that he has made.

Hope this helps.

Steve

I am going to make a tap for my hiatt cuffs and after careful measuring I have determined the thread as 7/32 whit 12 tpi. The 12 came from screwing in a piece of plastic tube onto the concealed screw then then slicing the tube longwise and measuring the wear marks, simple but effective.
Chris in Australia

You're right, the thread is between m6 and 1/4 hence 7/32 and being English , assume whitworth form

Another Aussie key maker. I look forward to seeing the finished product.  Have you a photo of the cuff you are working with? 

Welcome Chris. Paul in Melbourne.

Ian is the expert on making Darby Handcuff keys. I am sure he will agree there are at least 8 different threads and you can add another 4 for the left hand threaded keys.
The bolts vary in size from 0.21 to 0.26 inches and the pitch varies from 12 to 16 tpi. They are NOT a standard Whitworth thread and are more of an Acne type thread. Photo attached showing 4 bolts.

Thanks Chris, 
I have over thirty test tubes (threaded tubes to test in cuffs) in my darby kit . Most makes of English darby and European . Handcuffs and leg irons,  American and other screw key models. (also plug eight cuff keys and matching plugs)