Modern handcuff failure points

I have been watching a video from a US law enforcement officer talking on a live stream. He got a question about the life, usage and replacement of handcuffs.

The officer said typically they use handcuffs until they break and don't replace them before that. He said usually they break while on the person and they can't get them off, so it's not too much of a risk for the officer as far as securing people. They take them back to the station and cut them off. But he said they usually fail on the person and they cannot undo them. So this got me to thinking. I am not an expert but I have seen handcuff cut-throughs and have had (and still have some) many handcuffs over the years in my collection. So what exactly are the things that could be going wrong with the handcuffs that would get them stuck on the person to where the key does not work?

This is the example that he has:


I am torn between thinking it's a problem with the key or the cuff. Since the key gets stuck, at least in THIS particular instance, I personally believe the problem is with a worn key that the bit on the end is either no longer sticking out long enough or has become rounded so that it catches on the ledge of the pawl to raise it but too much force during the keyturn and it scoots off the ledge and the pawl snaps shut behind it. That is my only theory at this point.

If anyone with more experience has any points to add to this on how modern handcuffs fail during use and why it happens? I would be very interested and I think it could be helpful for people in occupations where handcuffs are used, so that perhaps people can make better decisions on maintenance and replacement.

On Handcuff day in my police academy, one of my fellow cadets got his brand new Peerless cuff stuck on one of his wrists.  Since it was not double locked, I was able to shim it open.  The also brand new key got trapped inside the lock.  I told him to return the cuff for another so I never had the opportunity to take the cuff apart to see what exactly had failed.  I wanted to get some catsup from the cafeteria and smear it on his arm when walking back to class but he was not as warped as I was. Would have been a memorable time for the class when they thought I butchered his arm all up. 

Close to me, there is a training facility that trains snipers and such to fight in Afghanistan.  Twice they brought over an unfortunate trainee to have me cut the cuffs off.  They had the exact same problem that I had in the academy.
The best way to cut off a cuff is; get a bucket of water, a rag and a Dremel.  Stick the rag under the cuff and dunk the arm in the bucket of water. Cut the bow as close to the lock as possible.  Every 3 or 4 minutes, dunk the arm in the water.  It takes about 10 minutes to do it as it is best to go very slow.
  

So perhaps this is related to my theory, but in this case maybe a defect from day 1 where the ramp that comes into contact with the key flag was malformed or not long enough it's self, so the key was able to scoot off the end with enough force? If the key gets stuck farther into the cuff than normal with no way of seemingly getting the key out, it is the only thing that makes sense to me. Which would explain why it happened with brand new cuffs and why my theory would happen after worn keys are used.

If you see this again, try this theory. Shim the cuff open to free the person if you have shimming ability near by, then if the key is still stuck, turn the key as far in the same direction as normal to undo the single lock, then manually push up the pawl while you have the rotating arm not engaged and while the pawl is pushed up (simulating the normal key mechanics) see if you can crank the key backwards and free the key from the handcuffs. I believe that might work. Although if the issue happened with a brand new key and brand new cuffs, they should be returned. But if it's an old key that was the issue, a quick test with a new key with harder than usual force should determine if the cuffs themselves are defective. Hell, that may even be a good test for everyone with new cuffs, to try and "open" them somewhat (but not insanely) forcefully, in an attempt to expose a defect before the cuff gets on someone's arm?

The theory of the key's flag being to short has come into play in the past. Most notably, it happens when one tries to use a modern, standard key in a WWII era Harvard Lock Co. Cuff or leg iron. Once the standard key is inserted and twisted in the unlock direction, the flag tends to skip past the lever that moves the pawl and become trapped. You cant turn the key back to release it. Ron Spitz showed me, if you manually push and hold the pawl down, you can wiggle the key back and forth and get the flag to pass the lever and release the key. I had tried it for quite a while, not pressing down the pawl. It was a no-go until the pawl was held down. It allowed the flag to slip past the pawl lever, with a little bit of coaxing. I did have a set of Hiatt UL-1 cuffs fail after some use. The key, just wouldnt turn in the lock at all. Something was holding the pawl in place? I never figured it out. But, Hiatt sent a new pair as a replacement.
-Richard Knip-

In Russian handcuffs-related group there is an explanation of Peerless handcuffs flaw. You can use Google Translate to read the explanation
https://vk.com/photo-5531056_148372191

I just posted about a new set doing the same thing. New s&w model 1 handcuffs and new keys. Even tried other known good keys. Key ended up getting stuck and wouldnt undo the double lock. Had to cut them.off and sent back to where i bought them. Sure hope its not gonna turn into a issue. Its clearly a manufacturer defect on those. Also hoping the quality of new cuffs has not gone down.

IMHO the biggest failure of handcuffs used in North America is hands down the pathetic security offered by the "Universal Key." Steve Santini

Back in the 1980’s I had been working part time for an armed security service, and a friend, handcuff collector and fellow officer made the mistake of handcuffing one wrist of a detainee to a fixed object (possibly a door handle) while he went off to assist in the pursuit of a second escapee. Upon returning, he was unable to unlock the cuff on the detainee’s wrist, and it was thereafter determined that he had gotten ahold of a small paperclip with his free hand, and had tried to pick the cuff off while left unattended, albeit unsuccessfully. The mangled paperclip was discovered with a small segment broken off which was now lodged in the lock work. It was really a pity because these were early version S&W model 90s in like-new condition given to him by his father, and the bow had to be snipped with a bolt cutter.   

Jason
 

I often wonder how hard it would be to open up a pair of cuffs now a days. They still use rivets on 99% of modern cuffs so its just a matter of drilling those out. Not sure where to buy replacement rivets tho. As far as the bow.s it could be welded back together and renickle coated. Would be way more vs just buying another set, but like dogs, some are sentimental

This thread reminded me when I was in Jr College in the late 1950's.  A friend brought me a pair of Japanese handcuffs-no key-and asked me if I would like to have them. Of course I did and another friend asked to see them and proceeded to put them on both wrists and proudly showed everyone.  After everyone had their fun, he asked me to remove them but I had no key.  I went home to get some "tools" and he went to class which happened to be a drafting case (descriptive geometry).  So, you can picture him handcuffed with a pencil in hand sitting at a drafting table.  Anyway, I could not get the cuffs opened so we went to a locksmith who had a key that would fit.  I still have the cuffs in my collection.  

Ron

ronspitz wrote: This thread reminded me when I was in Jr College in the late 1950's.  A friend brought me a pair of Japanese handcuffs-no key-and asked me if I would like to have them. Of course I did and another friend asked to see them and proceeded to put them on both wrists and proudly showed everyone.  After everyone had their fun, he asked me to remove them but I had no key.  I went home to get some "tools" and he went to class which happened to be a drafting case (descriptive geometry).  So, you can picture him handcuffed with a pencil in hand sitting at a drafting table.  Anyway, I could not get the cuffs opened so we went to a locksmith who had a key that would fit.  I still have the cuffs in my collection.  

Ron

Click to expand...

Love see what those cuff a look like

94104, the problem is you can drill the rivets but most modern handcuffs have a ditched jaw, as I have seen it referred to. Where the rotating arm has a groove and the cheek plates of the cuff have a peg or protrusion which fits in it, so if you were to drill the rivet or cut the arm, it's movement would be minimal since the cuff arm would be trapped by the teeth of the pawls and be prevented from pulling away from the teeth by the groove/peg system. For full success you would need to cut either the arm as close to the rivet as possible to create a large enough gap for the wrist to be CAREFULLY moved through, or cut the double strand area high up near the body of the cuff which would swing freely and open up a gap on the wrong side than usual.

I wish I could edit posts...... The arm would need cutting near the body as the other side to allow it to move around the pivot unimpeded.

if you can drill the hinge rivet, you can drill the semi stamped dent or pin so it doesn't impede the bow via the milled groove. it's not rocket science.

duh wrote: if you can drill the hinge rivet, you can drill the semi stamped dent or pin so it doesn't impede the bow via the milled groove. it's not rocket science.

Try it and post pics. Tell us how long it takes and try to use a real person so they can tell you when the heat is starting to burn them. Would live to see your results

if you create heat drilling 1/8 thick mild steel, you are either using a blunt drill, going too fast, or have never used a drill in ya life. 

Maybe I am missing something but wouldn't all restraints succumb to power tools?

If you want to address points of failure on modern restraints, we should probably start with proofing these things from chain binding. I have said this over and over again but the call for attention to this weakness continues.

I said it before and I will say it again.. you can develop the most secure, most hardened, most key restricted, most pawl engineered handcuff in the world, but if a subject can simply bind the chain and break them, what the hell does it matter?

CTS manufacturers a handcuff with an O ring design but only in oversize models which are not practical for routine use. Why they can't or won't implement that design into the standard size trimax is beyond me.

If you want to address failure points start with this. Then worry about what kind of damage a drill can do.

I wanted to add this.

Watch out for those bad guys with their Waterpics!

Here a Special Forces instructor demonstrates the chain binding technique.

grenchat wrote: Watch out for those bad guys with their Waterpics!

Here a Special Forces instructor demonstrates the chain binding technique.

Click to expand...

This guy repeats his self way to much. Good cuffs break easier than cheap ones and i dont see this working behind the back. I just saved you from watching it. Your welcome

That is also the same guy who got arrested for going to a locksport tree place in America somewhere, where people snap padlocks onto this constructed thing where people leave a padlock signifying the love between two people. He went there and picked all the locks and I am not sure what he did with them. lol. Nice guy..

silentbd wrote: That is also the same guy who got arrested for going to a locksport tree place in America somewhere, where people snap padlocks onto this constructed thing where people leave a padlock signifying the love between two people. He went there and picked all the locks and I am not sure what he did with them. lol. Nice guy..

Wow they arrested him for that? Seems harsh since most of those " love locks" places remove them once they become to many and start to weight to much on fencing and such. That place in paris removed alot awhile back.

Here's the article, or one I just found of it: https://www.reviewjournal.com/crime/loc ... vandalism/

Once found a Harvard legiron with a jammed (not original) key. The jammed iron was double-locked. I purchased it and picked the double lock open. The key then came out easily. I obtained a proper key, and the irons work well.