Repairing my Big Vise by Making a Spring

Recently I’ve acquired a very large vise that I am planning on using for blacksmithing projects. The vise was very cheap but there is one thing wrong with it: it doesn’t open. In this video I’m figuring out what’s wrong with this engineering vise. Then I am going to fix it by replacing the part that wasn’t there. I’ll do some spring making and make a lot of mistakes. If you have a broken vise, this might be the video that will help you get it back in working condition. By the way, is it vise or vice? Let me know in the comments.

Video transcript

Hello ladies and gentlemen, welcome to Tony Needs Hobbies. My name is Tony and recently I picked up this big vise. It weighs 27 kilograms or about 60 pounds has 7 inch jaws and it only cost me 20 euros which is about 22 dollars. That is a steal, but there is one big problem with it: it doesn’t work. So in this video I’m going to try to fix it.

This vise is in decent enough condition for me to use it so I’m going to fix it and not restore it. In order to fix it, let’s first have a look to see what’s wrong with it.

While closing the jaw, the vise seems to work okay. The problem pops up however, when opening the jaw. As you can see here, when rotating the handle, the screw moves outwards, but the sliding jaw stays put. The reason that it doesn’t move is that a spring is missing over here. Normally there would be a spring holding the screw to the sliding jaw preventing the screw from moving out without taking the sliding jaw along with it. I have this smaller vise where you can see it on a smaller scale. Because I can’t find any affordable replacement parts, I guess I have to try to make my own, so that’s what I’ll be doing. I don’t know much about metallurgy or springs so I will make some mistakes so you don’t have to! But first, let’s disassemble everything.

This vise is quite easy to take apart. It only consists out of three main parts: the base with a fixed nut, the slide and the screw. To take it apart I just have to unscrew the assembly until the screw comes out and all parts are separable. I couldn’t find a video anywhere on how to fix this, so I decided to document myself fixing as it might be useful for other people with a similar problem as well. Did it help you? Please let me know in the comments!

The screw measures 25 mm in diameter so I ordered some spring stock that I will cut the appropriate length spring from. I also got two big washers to fit the screw and a long 6mm thick mild steel nail. The work on the spring is the most work so let’s start with that.

The first step is marking where to cut it and cutting the spring to size: 40 mm in the case of this vise. As you can see by the amount of sparks, this spring is made from some type of high carbon steel. That’s good to know for the heat treatment process later on in this video. But let’s get back to shaping the spring. After cutting it, I need to bend the end flat so it will sit flat to the washer when the whole vise is assembled. Using a torch I heat it up and then shape it using a hammer. When it sit’s flat I let it completely cool down.

You might ask: “Tony, why didn’t you just order the correct length?”. Well, I could have, but ordering a custom spring was super expensive, around 60 euro’s for 40 mm length. This entire spring however, only set me back 10 euro’s but requires some work to be done.

Then it’s time to grind the spring flat. I do this with a small belt sander. It does get hot while doing this so once in a while I cool off the spring in some water. I really enjoy seeing those beautiful sparks, but be careful and wear personal protective equipment, in this case eye protection, hearing protection and of course respiratory protection as well.

That looks nice and flat, so the shaping of the spring is done and it’s time to move on to the next step: heat treating. Like I said before, I don’t know much about metallurgy, so I asked the vendor of the big spring what they would do to heat treat the spring after heating, bending and grinding. They told me a simple annealing would be fine, but I decided to heat it up and water quench it. When experts tell you to do something, just be smart and follow up the advice. Don’t make the same mistake that I will make here. Water quenching will cool it down too quickly and here is the result after trying to compress the spring.

So I had to make another one for which I will follow the vendor’s advice. I tried to heat it as evenly as possible, kept it hot for about 10 minutes before letting it gradually cool down. I don’t have any special equipment so I decided to temper it as well for two cycles at 300 °C in the kitchen oven. That worked well. Even the water quenched part, that I tempered as well, is springy again and didn’t break when compressing where this non-tempered piece can be snapped in pieces quite easily. Looks perfect, so let’s prepare the other parts.

From this 6 mm mild steel nail the head will be cut off after which it will be cut into a 40 mm piece. It will hold the spring and two washer in place to secure the screw to the slide. Cutting is easily done using a hacksaw. With a file I then take off any burrs. To the washers I don’t have to do any work. They are very cheap so I bought the exact sizes required. 25 mm inner diameter with a 40 mm outer diameter.

With all the pieces finished the vise is ready to be assembled again. I did clean all the dirty surfaces and took away any old hardened grease so I first apply a generous amount of ball bearing grease to all contact surfaces, because that’s what I had plenty of lying around. The screw goes through the slide. Then the first washer goes over the screw on the inside of the slide. Then the spring is slided over the screw as well as the second washer.

Then comes the hard part: I have to compress the spring in order to put the mild steel rod through the little hole to secure the spring assembly. In order to do that I cut a slot into a piece of PVC pipe that I found in my shed. Using my body weight against the slide and the pipe against the wall, I managed to compress the spring just enough so there is room to fit the rod in. With a small blow of a hammer it went right in and fit perfectly. It wasn’t so hard as I thought and as you can see all the parts fit together very well.

And that brings me to the final step and that is putting everything back together and testing if it works again. Here you can see it goes in smoothly, but that was already the case before I did any work to it. Most importantly the sliding jaw opens up now too, so I’m happy that I managed to fix it.

Well, it was a challenge but I managed to get this vise back into perfect working condition. I hope you can learn from my mistakes to fix your vise too. I intend to use this vise for blacksmithing and if you’re interested in that topic as well as many other topics that I explore on this channel be sure to subscribe so you don’t miss content like this in the future. I hope you have enjoyed watching this video and if you did then let me know by hitting that like button. And that’s it for now. I’d like to thank you for watching. Bye, bye!

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