Paracord Self Defense Key Fob. (Black-Jack)




Edit 30Jan2017: Well, since I posted this instructable back in 2011, many different variations have cropped up that are very similar to my original if not based on it. I think that is awesome if those guys based theirs on mine, and I am glad. I have an updated design that I'll be posting soon to try to keep it fresh. Keep an eye out!

I have looked around the internet trying to find out if someone else makes these like I do. All I can ever find is a monkey fist attached to a cobra weave, or the same with just an extra length of cord. I hope that this helps someone, and that it is as enjoyable to make as it is for me.

Supplies needed:

1. 1 3/4 inch steel ball ( I used an old mouse ball with the rubber cut off of it.) you can use a larger one, but you'll have to augment the length of cord needed.
2. About 20 feet of 550 paracord cut into 2 10-foot lengths (better to have too much as not enough.)
3. 1 D-ring, or similar item of your choice.
4. 1 shackle and a key-ring.

1. A pair of forceps, or a scribe ( looks kind of like a small icepick.)

Start with a monkey fist knot,

but make sure you do four raps for each side, and instead of only having a short length of cord on one end you want an even couple of feet on both ends when its done.
You will need this to make the handle. Once you have your monkey fist made you'll need to thread the other length under the two middle strands between the ends where the cord comes out of the monkey fist, and pull it through where it is even in length on both sides.
Then you use the cord lengths to make a "Round-Crown Sinnet," which is just a crown (box knot) with a twist....

Practice the round-crown sinnet to see how to make it with the monkey fist. The picture should help as well I hope.
Just make sure that you are tying it very tightly, or it will be floppy. (which is embarrassing... ha ha)
Keep tying, making sure that it is as tight as possible, until your desired length is reached. I usually make them about 20 knots which makes for a pretty good fob / aggressor deterrent for my key chain. when you get to where you want it insert the D-ring and tie two more regular crown knots to lock it in.
Trim the excess off and burn/ smear the plastic before it cools to make sure it won't slip out.

Remember: This is a dangerous weapon, and should only be employed in dire circumstances where there is no other option.
I take no responsibility for any injury that you cause to yourself or others. Having said that........

Thanks for trying out my instructable. Let me know how it works out for you, and if you like it.

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24 Discussions


8 years ago on Introduction

I read in a book that sailors used to make these, but instead of a monkeys fist they used a star knot, and 3/4" rope. Your's is a bit sleeker, and probably more effective, because of the steel ball. As soon as I get some more paracord, I'm gonna make one to keep in my car.

2 replies

Reply 4 years ago on Introduction

I was in the Navy, and a bosun's mate showed me how to make this. He made a monkey fist with a steel ball in the center.


Reply 8 years ago on Introduction

I am very pleased that you like my instructable. you can also make it a touch shorter and it makes a great keychain. i carry the full-sized one on my keys everyday, and it is one of the three in the photo.


3 years ago

I'm happy everyone enjoys my instructable. It's been a while since I've gotten on here, and I'm about to submit a new killer post. Keep an eye out.


Reply 3 years ago

I imagine you could, but with smaller cord you'll need a smaller ball, or a few more wraps on the monkey's fist.

dharber ii

6 years ago

You forgot to include in your steps that you do the wall knot alternating with the box knot. That's what people mean by the swirl thing.

1 reply
ampstardharber ii

Reply 3 years ago

Its a round crown sinnet. that is what I called it, and attached a video of how to do it. Thanks for your input though.


6 years ago

Anyone willing to sale one of these if so how much and can u ship it


6 years ago on Introduction

I consider the Monkey's fist as a great key ring fob. The weight makes is very easy to hold, the ball can be used to break glass if needed and I could use as protection if req. An all round good thing. Good tying.


7 years ago on Introduction

thanks for a great instructable! However, I'm sort of confused as to how to start the crown sinnet (yep, I'm feeling kind of stupid, haha!). The video appears to show tying the knots with two *free* ends of the two cords, but the cords are taken up on one end with the monkey do I start the crown sinnet?


7 years ago on Introduction

ampstar nice job.i have also been making mine like yours as well as with 4 strand braid. started with 3/4" ball bearing up to 1 1/4" a real gourd smasher.

2011-12-10 2011-12-10 001 003.JPG2011-11-17 2011-11-17 001 001.JPG

7 years ago on Introduction

I'm not into making my own. Various reasons. But a large steel ball, over 1" in diameter, on a rope that just fits over the hand sounds great. I8nite says a staffordshire terrier is a deterrent. I agree. My Golden Retriever alerted me to the possible presence of a wild pig on a late night camping trip. The growling and barking could have saved my life. The monkey fist is useless on wild pigs but sometimes the problems are more human than animal. Or human animals. I want to buy at least 2, maybe 3, of these. I would want two to be compact and the third to be a bit longer to give the swing more impact. And I want a larger steel ball inside than what I have found thus far on the net. I guess I could make my own, but would prefer someone with experience make it. Are you interested? If so, how much?

Peace out unless someone attacks you,



8 years ago on Introduction

Just so you know, what you've made is illegal in most states (these fall under the heading of a concealed weapon). So I suggest you check your local laws before carrying this around.
Otherwise, nice idea.

Source: Myself, I collect and research weapons and I work with law enforcement.


Reply 8 years ago on Introduction

Watch the video for the "round cown sinnet." it is terribly easy to do. you will just have to tie an extra core "box knot" sometimes to keep the outer edge from colapsing in on itself. let me know if i can help more with this for you.


Reply 8 years ago on Introduction

I understand the "round crown sinnet," but am not sure about the twist you do afterwards. Do you just take each of the four strands and thread them over/under clockwise and then make another round crown sinnet?

Finished product looks great, will make a few of these once I get the twist figured out. Thanks!


Reply 8 years ago on Introduction

Each layer is a round crown sinnet. The twisted look happens all on it's own. Just keep it as tight as possible.