Hot answers tagged

58

The answer is surprisingly simple: the bolt expands, but the nut expands more. What is happening here is good old thermal expansion: The bolt is heated and expands outwards, its radius increasing The nut is heated and... expands outwards, its radius increasing Now, since the nut's radius is slightly greater than the bolt's, and since the increase is ...


55

Washers are used for multiple purposes when mechanical parts are assembled using bolts and nuts. Here are some usages and as you can see it is not likely that a generalized answer can be devised to directly answer your question! Some washers have a special design that attempts to help keep the nut and/or bolt from coming loose. Known as a lock washer these ...


29

The secret is constrained expansion. Here's some cruddy diagrams to help explain how it works. Bolt stuck in a hole When the bolt is heated, it expands. Since the shaft of the bolt is constrained, it can't expand inside the hole. The bolt expands in the direction of the green arrow, but cannot expand in the direction of the red arrows. As the bolt ...


27

The actual reason this usually works is that rust is significantly larger than the steel it's rusted from, which is why the bolt is stuck in the first place. In some other instances the reason heat works is that the bolt was applied with a threadlocker that requires heating to remove (if it comes out with no sign of rust, that's a pretty good bet) Many ...


20

That's likely a cleanout for your sewer line. When opened, you can run an snake down the line to remove any blockage without ripping out your entire foundation. Here's what it would look like from the side: And the cap itself can have different styles:


20

If there was only one washer, it generally will go on the nut side as the nut has less surface area in contact with the thing being connected than the bolt side.


15

I start by hand tightening as much as I can, then I tighten a little on each side and check if the toilet moves. If it does then I tighten a bit more, check and repeat until there's no movement. You're trying to avoid bowl movement, so that it doesn't shift or fall over, not to hold the floor up by the toilet bolts. As tight as you can go will probably ...


11

After cutting the bolt to length, use a stationary grinder instead of a file to clean up your work. With a grinder, it's easy to square up the end of the bolt and apply the chamfer that you want. Just be careful, especially if the bolt is shorter than the grinder's table. If the bolt is short, use a pair of vice grips to hold the bolt during grinding. And ...


11

Metal arranged in a ring expands outward when heated. Imagine a ring of thin wire being heated--it expands primarily along its length, making both the inner and outer diameters larger. The same occurs with the material around a bolt hole. Generally, I try to heat the surrounding piece and not the bolt itself. However, even if the bolt is heated directly, ...


9

DANGER DANGER DANGER.... As we speak, I am replacing an entire 5 foot knee wall 20 feet long, jacking the floor joists, new studs, mold remediation, new sills, new top plates, new insulation, floor joist sisters, a very expensive 6 foot slider is in jeopardy. This fix is gonna cost my customer over $3,000 minimum Ants and rot everywhere, all the way to the ...


9

Unless your holes match the bolt size very precisely (like, you have to hammer the bolts home), you will get racking, which will weaken the joint over time. Likewise, the bolts will loosen up (use lock washers and check it frequently). It's something you'll have to watch for; as the holes get stretched, you'll need to figure out what to do. Think about how ...


9

I would try a Dremel type tool with an abrasive cutoff wheel. Of course you need to be careful of the porcelain. I've cut many screws and bolts this way. If you can't cut the bolt, you may be able to cut the nut, in the direction of the bolt's axis, then pry the nut apart at the cut line.


9

It's called a spanner slotted (or slotted spanner) head. Useful site here. Hard to find in the UK, why the owner used one I cannot imagine. Screwfix doesn't have them. This site may do, although it is international. You'll need to figure out the correct size before you order. Alternatively get a real cheap flat-head screwdriver the right width and file ...


8

If there is only one washer used with a nut/bolt, it usually goes on the nut side. The nut in most circumstances is more movable, and is more commonly turned to tighten the assembly. The washer helps prevent damage to the surface of the object being fastened. In most cases where the bolt is easier to turn, the bolt has a round head that will cause less ...


8

Lock nuts and carriage bolts are a bad combination and even worse when trying to use them in material like particle board or MDF. You could try to use a Tee nut from the monitor side and then simply use a short hex head bolt into the Tee nut.


7

You have the basics down pat. The key to getting the threads working properly is: Squaring off the thread end of the bolt. Yes, the hacksaw blade will follow the threads slightly. If you have a bandsaw with a stock holding vise that can be squared to the blade, run a single nut on so the hexes will hold the bolt in place as straight to the blade as ...


7

One thing that will help prevent the porcelain cracking is to use a rubber or plastic washer between the head of the bolt and the bowl. This will take some of the "excess" force by deforming slightly, and by checking for the washer deforming as you tighten you'll have an extra visual check that you've applied enough force.


7

A welded connection can always be made the same strength as the original steel by using a full penetration but weld but this all depends on the quality of the materials used for the welding and the quality of the welding itself. Therei s a very good reason why there is a lot of non destructive testing used when welded joints are being used for structural ...


7

The caps come with a washer-type thing that they clip into: Your toilet clearly does not have these clips. Using silicone is most definitely not the correct way to attach these, so maybe the installer lost the clips or just has never installed a toilet before? It's normal to cut the bolts to length, as the length needed depends on the thickness of your ...


7

A typical toilet has a flange that's bolted to the floor and stays there. Bolts are then turn upside down, with the head down, and the toilet sits on these. The threaded end faces up and the nut goes onto it. So, a typical toilet install is closet bolts that have threads facing up. No need to go under the floor, be it a 3rd floor bathroom, a 1st floor ...


6

Lag screws should be fine. If possible, have them go into the ends of the floor joists as well. You can probably see where they are from the outside by looking at where the nails are in the rim joist.


6

Are you using an eye bolt or an eye screw? OR         For an eye screw, glue won't do much and is not needed. (Although some glues may act as a lubricant when you first screw-in the eye-screw.) Use bar soap or beeswax as a lubricant. For an eye bolt, especially if you want it to be able to pivot, use appropriate washers, plus two nuts with a lock-washer ...


6

[Gregmac beat me to the problem description, but see the steps to fix it below.] The snap on caps often come with a plastic piece that goes under the washer. This is what the cap snaps onto, and without it, it won't stay down securely. It looks like the contractor forgot about those, or possibly you have a style that doesn't require it and it snaps on a ...


6

In many cases an unthreaded shank provides a better, more secure fit when mating to the components that it connects. Where lateral movement is a concern, this type of bolt should be used. In other cases, it's important that there be no pull on the upper portion of the material being joined. Threads would create drag that may counter the bolt's ability to ...


5

Two nuts can be tightened against each other so that they won't come loose. A single nut can be tightened against whatever it's holding, and if that's wood, the nut can loosen as the wood changes size with changes in humidity.


5

This sounds like old school plaster on metal mesh, common for that era in apartments and condos. Hard as a rock. However, you'd have to open up the wall to find the concrete block that's most likely behind it, because the plaster is only supported by furring strips tacked into the blocks with nails. Do not be fooled if your stud-finder scores a hit. Don't be ...


4

Are you comfortable with cutting the bolt to a length between 2" and 3"? That would be simplest. Another possibility would be to use another piece of wood between your shelf and the wall to create more thickness for the 3" bolts. If the concrete is actually concrete block, you can drill into that quite easily with a masonry bit from your local hardware ...


4

Under perfect conditions this is not true. However most of us are unable to weld something under perfect conditions. There is always the risk of contaminants, imperfect welds, incorrect temperatures, etc. This holds true even in many industrial factories. For this reason, some very high end cars have their frames glued together instead of welded. You ...



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