Questions tagged [fasteners]

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Remove stripped screw inside of a tube

I have a stripped screw inside of a tube (see picture): The size of the screw is M2 and it seems to be glued. This is part of a camera objective so I want to avoid impact (e.g. tapping with a hammer)....
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1 answer
54 views

Why aren't fasteners open standards?

I just wanted to find information for an M2 flat head hex socket machine screw which, I believe, is defined by ISO 10642, but unfortunately that is locked behind a paywall of a couple hundred dollars. ...
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3 answers
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Is it possible to tap a hole partially through a 3mm aluminium sheet?

I would like to secure components to an aluminium sheet that is 3mm thick. Ideally I do not want to drill holes all the way through the sheet because it is important that a seal is maintained. I am ...
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Which side is "up" on this nylon nut?

I have this nylon nut, and I wonder which side should contact the material: Is it the wide hex face, because the nut is built like a lock-nut? or is it the cylindrical face because it serves as an ...
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1 answer
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What type of rivet is this?

This is a pivot point on a linkage in my coffee table. It appears to be a rivet with a tail that was pressed with a cross-shaped punch to widen it. I haven't see something like this before. Is there a ...
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1 vote
3 answers
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Steel bracket fixing spacers on a wall

What could I do to address the uneven vertical wall (not plumb) behind the bottom of the steel bracket? Would you fill in the gap with sand/cement and once dried tighten the bolt or use steel plates ...
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1 vote
1 answer
48 views

Screw Calculations/Math

At the risk of every woodworker in the world snickering at me, I'm curious how strong my wood joints are and want to know how much weight a table supports. I'm an aero engineer who ended up in EE, but ...
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1 answer
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Unable to understand minimum length of engagement for bolts

I've attached a snap of the part I'm unable to understand Machinery's Handbook 29th Edition. Here's a link to the ebook as well https://www.vtc1.org/cms/lib/PA03000913/Centricity/Domain/21/Machinerys%...
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  • 37
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3 answers
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Does the nut experience the same forces a bolt experiences but in opposite directions as reaction forces?

More specifically, if I have an eye bolt being used to lift a body, I can find the various stresses acting on the bolt, but I want to know what happens to the threaded area of the body where the eye ...
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1 vote
2 answers
114 views

Solutions for a slanted roof

I'm using I-Joists to span this 27' vaulted living room and create a shed style roof. I've got two problems. Because of the angle, the joist won't make full contact with the walls (short of 20 years ...
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1 vote
3 answers
296 views

What is the real name of those rivet-like plastic fasteners?

I'm trying to find the name of a removable fastener operating by a deforming retainer in the front like in the picture: [ All I found online are Alibaba and similar listings that don't seem to contain ...
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5 votes
4 answers
1k views

Why can't screws be used for locating parts?

I remember hearing awhile back that it's not a good idea to use screws to locate/align parts. Why is that? Apparently dowel pins, or "locating pins" should be used instead. From my ...
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2 votes
4 answers
730 views

Are there any benefits to using a regular washer alongside a lock washer?

I am new to fasteners in general, and was wondering if anyone knew if it was acceptable to use a regular washer underneath a split lock washer. There are two applications, one is on top of a 3D ...
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23 votes
5 answers
5k views

Why exactly does a washer help distribute the stress around a bolt?

Usually the reason for having a washer under a bolt head is stated to be that it helps to evenly distribute the stress to the clamped material surface. But why is this? I would understand if the ...
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1 vote
3 answers
260 views

Mechanical fasteners made of HDPE?

I need to fasten pieces of HDPE together but I’ve heard gluing HDPE is difficult (after all, glue comes in HDPE containers, and the glue doesn’t get stuck in the bottle). Using mechanical fasteners ...
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Thread adapters larger than 1/2"

I have a 1/2-20 stud that I need to step up to a 3/4-16 stud. I searched around for 1/2-20 female to 3/4-16 male thread adapters, but was only able to find such a product on McMaster for sizes 1/2 and ...
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0 answers
312 views

Maximum strength size thread for aluminium sheet per thickness

Is there a rule of thumb, or a table which helps one determine what is the maximum strength thread size to use for aluminium sheet? I am interested in threading 3mm, and 2mm thick sheet aluminium. I ...
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1 answer
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What type of fastener / rivet is this please?

I think I may have worked this out but I would love it if a real engineer could confirm it please? Is the fixing shown in the photos a shoulder rivet? Semi tubular? For the record the pictures show ...
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1 answer
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What type of fastener is this? How does it work?

I'm trying to find more information on this type of fastener. It looks like a variation on a bayonet mount but I'm not exactly sure how it is locking in place.
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2 votes
1 answer
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Are concrete screws suitable for repeated removal and reinstallation?

Is a concrete screw like the HILTI HUS3 removable? I.e. can it be repeatedly unscrewed and reinstalled as required? Will this damage the fixing or the hole in the concrete? We're thinking about using ...
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2 answers
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Mounting a digital indicator on a plate

I have a flat aluminium plate and I need to mount a digital indicator[1] on it. The digital indicator doesn't seem to have any mounting holes itself so I think I need to use a clamp to hold it. I don'...
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2 answers
763 views

What is Proof Load of Bolts?

I seem to be getting conflicting information. Shigley's Mechanical Engineering Design textbook states that, "proof load is the maximum load (force) that a bolt can withstand without acquiring a ...
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0 answers
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Is there a term for this kind of eccentrically threaded fastener or washer that has wrench flats and curved faces

Is there a standard term for this fastener or for the kind of problem it is intended to address?
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1 answer
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Mounting methods for thin wall cast aluminum

Having a cast aluminium enclosure with the 3mm wall thickness. now I need to mount this to a mounting plate which fixed in vertical walls. can I have some idea on how should I choose the appropriate ...
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0 votes
1 answer
29 views

Fasten adjustable perpendicular cylinders rotating on axis

What part(s) make it simple to secure two perpendicular cylinders together when one of the cylinders is rotating on its axis? In the drawing below, C(3) rotates with a simple motor. C(1) and C(2) ...
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1 answer
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What is the best way to fasten securely a load onto a hollow brick?

Due to the ongoing COVID pandemic, I decided to put a basketball hoop on one of our outside walls, so that me and my son can stretch a bit. The problem is that the wall I plan to put the basketball is ...
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classes and grades of steel and stainless steel

I'm trying to learn the standard nomenclature for the steel and stainless steel mainly used in the bolts, screws, nuts, and other fasteners in general. So far I have created this table: | Metric ...
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1 answer
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How to remove/replace a screw with a lock washer in a tight place

I'm trying to remove the screw in the images below from a metal cover. The screw is locked in place by what I believe is called a locked washer. The screw can rotate, but I can't move it in and out. ...
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1 vote
1 answer
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Detachable tubing connections (joints) for frame assembly

I am looking into fabricating a steel tubing frame that needs to be dis/assembled (applies to many larger furniture like bed, shelving unit, wardrobe, cupboard, cabinet, ...). What are the variants of ...
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3 votes
0 answers
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Aerospace bolts and washer combination

In my aerospace company we have repetitive discussions regarding the stacking of low tolerance fasteners with non-countersunk washers. For example a fastner NAS6703-X (size 10) has a max. base radius ...
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1 vote
1 answer
486 views

Distribution of Forces into 3D Bolt Group

I'm trying to create an Excel spreadsheet that takes a 3D bolt group with x y and z coordinates, applied loading, and determines the distribution of forces into each bolt based on weighting by the ...
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0 votes
1 answer
471 views

What's the best way to design a joint with two fasteners?

When you're trying to design a relatively long joint with only two fasteners, what's the best way to arrange them? Since fasteners effectively radiate a circle of clamping force around them, what's ...
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-1 votes
1 answer
64 views

Serrated locking part

I need to fixate something at adjustable approximate angles. It doesn't need to have a lot of holding power. So the idea is to have washers/nuts that are serrated, that when closed in together, locks ...
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  • 149
-1 votes
1 answer
22 views

Looking for the name of this torque-arm post (to order one OTS)

It is a post that has an arm that can swing out so that you can torque on the post. I've seen it before but not sure where!
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2 votes
2 answers
3k views

M# Screw mm per turn?

So is there a standard rule of thumb, or equation about the distance the end of a screw will travel per rotation? Conversely, how many turns it will take to travel a specific distance? Say I have an ...
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0 answers
23 views

"Barbed" fastener, ideally with a release

I'm trying to identify a fastener or type of fastener. I have a stud/post that comes up through a board and the fastener is something that would push on and hold in place. Ideally it would be ...
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1 vote
1 answer
2k views

What does "Lg" mean when defining form of screws

The context of this question is the Form, Fit and Function (FFF) rule defined in ASME. It states that form is used to define any product with reference to its size, mass, shape, dimensions, and other ...
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1 vote
2 answers
536 views

Can I use a NPT fastened device to vacuum or 10^-2 Torr?

I am designing a flange to be use to maintain a pressure of 10-2 Torr for at least 3 months. I am using an o-ring seal from my (device) to the product weldment. I am looking for feedback on using NPT ...
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1 vote
0 answers
30 views

Permanant extension for Fastener

I have a fastener with an accessibility problem. At the time of installation, the fastener is at the bottom of a crowded box with obstructions varying stiffness (Metal Plates and harnessing). It is ...
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1 vote
2 answers
48 views

Dimensioning of beam pressed by screw in assembly

I need help dimensioning a screw-beam system of a press. I built one prototype but the beam is bending too much. Below is a sketch of my press. In the middle it has a fixing screw which presses ...
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4 votes
0 answers
228 views

Boeing 737NG pickle fork cracking. What determines the fastener layout?

Boeing 737NG aircraft are currently being checked for cracking in the "pickle fork" assembly that attaches the fuselage to the wings. The affected joint has 4 fasteners that attach the fork to the ...
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0 votes
4 answers
817 views

Fastening a Nut on threaded rod from the middle

Does there exist any type of Nut, that can be screwed on a threaded rod that can slipped in without having to go to the ends of the threaded rod? I can sort of imagine a Nut that was a ...
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1 vote
1 answer
93 views

Is there a rule of thumb to construe a screw

When your first idea is drafted you calculate which forces/pressures and so on are working on your system. And then you break the forces down into the single screws which are built in your device. ...
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6 votes
3 answers
682 views

What causes a fastener to lock?

I am rebuilding a car engine. With some of the fasteners I am unscrewing, I notice that a lot of torque is required to undo the fastener. It feels like a snap when undoing a fastener, rather than a ...
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0 votes
1 answer
97 views

What type of fastener is this?

Used to connect the chain for a window actuator to a U-shaped window bracket. The threaded end screws into a bolt hole (M5.5 female thread) on one side of the U-bracket. The tip of the fastener fits ...
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0 votes
1 answer
44 views

Correct sizing of fastener for console

Following situation: I need to mount a console holding a load to the edge of a 25cm concrete plate. I want you to check my reasoning. This is the situation: My thinking is: The load is 170kg, which ...
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0 votes
2 answers
69 views

Vibration table for tests (7-200Hz) from extruded aluminium profiles bolted together - good idea (?)

I need to design a vibration table (approx. 1000mx1000mm) to test products between 7-200Hz. I was wondering if it is recommended to make the table structure from standardised, extruded aluminum ...
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1 vote
0 answers
47 views

Recommended torque

I am working on an assembly where I have various screws, mainly metal on metal fastening. Where can I find a realiable source for recommended torque settings based on screw size, screw material and ...
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1 vote
2 answers
218 views

Help identifying a fastener/screw

I'm trying to identify the pictured fastener. It's a single piece around the arm of a gas spring, allowing it to pivot. I've had to replace the spring, but the screw is size M8 while the eyelet on the ...
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2 votes
1 answer
66 views

How to prevent movement in this 3 DOF setup?

I have a 3DOF platform that I'm trying to make more stable. It's difficult to explain in words what the issue is so I've added a GIF below. Any ideas of how I can get rid of this wobble? The DOF arm ...
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