20

My first thought is that it might be intended to be a wing nut driver of some sort, but those are usually hollow cylinders with slots for the wings. Ah ... sure enough, it's described as such in this Ebay ad:


10

As Dave Tweed points out, the ratio of torque to tension is lower the lower the lead angle is. Since the important measure of bolt tightness is generally the tension in the bolt, we want to achieve that minimum pretension with the least effort possible. Assuming we have to maintain a certain shear area of the thread (so the the threads are stronger than the ...


9

For any given size of fastener and given thread pitch, a single-start thread gives you the greatest mechanical advantage in terms of the torque required to achieve a given tension. Aside from acme threads that are often used on leadscrews for mechanical motion (e.g., CNC machinery), the only other place I have seen multiple-start screws is on self-tapping ...


8

When dealing with pressure vessels, you should not rely on rules of thumb. You should rely instead on the ASME Boiler and Pressure Vessel Code or whatever code is required by your local enforcement or regulatory body. There are far too many variables for a one-size-fits-all answer. The design pressure/temperature, materials of construction, flange ...


7

Not all cap nuts are self locking, some are, although they can be a bit weird looking. Nylocs are generally the first choice for general use as they provide good resistance to loosening due to vibration or flexing of the joint and will stay in position on a thread even when not under tension (unlike spring washers). Unlike locking adhesives they can be ...


6

I think you might have a misconception regarding to how far the pressure from the fasteners extends. One subject you might want to have a look into is "bolt joint stiffness". The most popular is the "Rotscher’s pressure-cone method". Essentially there is a pressure cone which radiates outwards with an pressure cone angle a. According to ...


5

There are a few ways to do this obviously it's easier to clean a through hole than a blind one. Run a clean second or plug tap through the hole. If you keep a tap just for this purpose it also has the benefit of keeping one 'fresh' tap which clean clean up any burrs of defects from worn taps when initially cutting the thread. Flush the hole with cutting ...


5

A Nyloc nut is a form of locknut. The purpose is to prevent unintended loosening. A cap nut is not necessarily a locknut. You can get cap nuts that have some form of locknut on the threads; but in general this is not a standard feature of all cap nuts.


5

Oxidation, dried lubricant, contaminants, rust - all that acts as a layer of glue binding the elements. As you apply a firm torque, you snap that bond. It takes a considerable time to re-form.


4

I've always referred to this style of female fastener as a "T-Nut"


4

It can also be used for fastening the 'eye' of hook and eye fasteners into wooden frames.


4

Granger Supply makes two different types:


4

*Figure 1. For McMaster-Carr 'Lg' is the length of the screw." Note that they specify the threaded length separately so Lg will be the distance from the bottom of the head to the tip of the screw.


4

Metric bolts use thread pitch in millimeters. Your M3 screw likely uses the standard pitch of 0.5 millimeters. One complete rotation of the screw will advance the screw into the work piece by that amount. According to the Bolt Depot chart, there is only one standard pitch for M3 screws, although other sizes will have standard, fine, super fine pitches ...


4

No, they are usually fitted once and left. If you need to remove them then you need to drill new holes. Or you should consider fitting a wooden framework to the concrete and attaching to that so it can be easily removed and refitted, without disturbing the concrete fixings.


3

In 1841 Sir Joseph Whitworth produced a paper on a universal system of screw threads. He then collected a variety of screws and proposed a universal thread using their average pitch and depth. The result was the 'Whitworth thread' with the depth and pitch of constant proportion, giving the 'V' thread a mean angle of 55 degrees and the number of threads per ...


3

Under high pressure and high heat metal bonds by a process called diffusion. Where the atoms of the two parts intersperse over time. This and oxidation, slow chemical burning of unintentional matrial and debris between the two parts, cause a strong bond that many times cuase the fastener to break before it can be removed.


3

You are on track with your beam calculations, but I doubt you will be happy with the results, just because a 3-D printed part is unlikely to act the way a cast or milled solid plastic part would. You would be well served to just buy aluminum bar stock and cut it with a hack saw. As to the screw force produced, I doubt you will be happy with that either. ...


3

A metric thread table is what you want. Table 1. Source: Anzor. So is there a standard rule of thumb, or equation about the distance the end of a screw will travel per rotation? It's not a rule of thumb - it's defined by the pitch. Conversely, how many turns it will take to travel a specific distance? Turns required = distance / pitch. Say I have ...


3

You could have a 8mm hole drilled and reamed slightly undersize for a press fit 8mm dowel pin and use a 8mm/8mm swivel clamp which would let you set the angle and height as desired (photo from McMaster).


2

I have always used the rule of thumb that the bolt has to be engaged at least one bolt diameter. This partly comes from looking at structural nuts. Structural nuts develop the full strength of the bolt in tension. These nuts typically engage about one bolt diameter.


2

Typing "screws" in the search field of the Bopla website finds this link. It looks like the screw you need is has a shank diameter of 1.7–1.8 mm and a thread diameter of 2.2 mm. The head is rounded.


2

I am not aware of anyone that makes such a beast nor have I seen one in the wild. What I have seen is head collars. collars are a tapered washer normally made of nylon but also available in metal that are designed to accommodate mismatched head taper. As they have no threads they can be used with multiple screws. Somewhere I have a box of them for #8 screws. ...


2

It is a pin with a threaded head. A normal bolt would not work in many chains that go through restricted passages, so the head in this case is designed to sit flush with the surface.


2

A standard bolt will stretch when tightened. This stretching increases force on the threads of both the bolt and hole and thus increases the force required to overcome static friction and loosen the bolt. If we exclude other materials and chemical changes to the surfaces then that snap that you experience is the moment you overcome that static friction ...


2

In a handbook of mechanical engineering facts you will find tables containing maximum load ratings for different diameters and types of screw fasteners, and required torque values to hold those loads. You will also find this data on the website of a company that manufactures screw fasteners. Most mechanical engineering design textbooks will contain a ...


2

In the world of machining, a lathe uses a feature called a half-nut. It's two half-nuts mounted on a slide in which they are separated to disengage the carriage from the lead screw, or brought closer together to engage the carriage to the lead screw. This stops or starts movement of the cutting tool on the work piece. The image above comes from Mini-lathe....


2

Are you going to continue pumping or have intermittent pumping ? As a engineering professor of sealing once told me "everything leaks, it is a matter of how much". Without continued pumping you will not hold that vacuum. For serious leak tight construction I have mostly seen Swageloc connections. NPT has no metal to metal seal , I think metal/metal will be ...


2

So, this may be what you try to describe: Image source: https://www.tractorsupply.com/tsc/product/lockdown-self-locking-hitch-pin-625 This type of device usually rely on an off centre hinge or pin and gravity to make them operate.


2

You may be able to use Nord-Lock washers for your project. The holding power is quite strong, as it is based on the torque of the bolt/nut, not on the washer. As you can see in the image from the web site, the surfaces of the washer are serrated in a manner similar to the detents in your image. The two parts are interlocked in such a way that rotation ...


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