# Tag Info

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 ...

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

*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.

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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.

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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'd recommend first making a hole to fill the channels in the brick with mortar/concrete locally. This way you will effectively have a solid brick which allows for a much stronger fastening and a much larger range of applicable anchors. The anchors you show above are all mechanical anchors, which is not the optimal solution when a waterproof result is ...

2

What you have is a circlip in a recess of the screw. You can see the ends of the "C" in the image, as well as a slight gap around the perimeter. A thin bladed screwdriver placed in the gap and rotated will cause the "C" to open, assisting in the release of the clip. If you have two thin screwdrivers, both gaps can be pried simultaneously ...

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 ...

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

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

First of all, I'd like to point out that you are mixing (not without reason) the concept of proof load which is intended for bolts and the concept of proof stress and yield stress that is intended for materials. Yield stress vs proof stress (and others) Typically, the stress needed to produce 0.2% of plastic deformation is considered proof stress (sometimes ...

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Figure 1. Clamping point. On the webpage you linked it appears that they hold the device on the 8 mm diameter rod sticking out the bottom. (Look at the press-mounted device.) To mount on an aluminium plate and have the back of the instrument in contact with the plate you just need a block of aluminium, steel, plastic, etc., and drill an 8 mm hole 11 mm from ...

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Proof load is the maximum load the bolt can carry without exceeding deformation criteria. Below are quotes from two sources: Proof load is an amount of force that a fastener must be able to withstand without permanently deforming. Proof load is defined as the maximum tensile force that can be applied to a bolt that will not result in plastic deformation. A ...

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The easiest way to maintain water resistance is to not puncture the enclosure. It looks like the box has holes extending through the cover down to the bottom, I'm guessing these are specifically for mounting? (The 2 large holes). Use those if you can. The next best option would be to attach the box so that the bottom is against the plate, and screws come in ...

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If you search on the internet on swivel joint for the rotating joint and under screwdriver joints for the fixed joint you will find manny examples.

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TLDR: NPT and vacuum - no problem - use correct type. NPT and o-ring - possible (likely) problem landing o-ring if you use a tapered thread style. Please post a sketch so we know the size of the thing and how the o-ring relates to your flange. NPT can be one of a dozen or so thread types. Some make sense and some don't. The most common NPT type is a ...

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If I understand your design correctly you extend the existing play in the mechanism. If you can’t eliminate the play then you can try to minimise it. See the locking pliers (https://en.wikipedia.org/wiki/Locking_pliers) as an example to reduce the play. The disadvantage of this principe is the distance decrease.

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