Double sided washers

[zeliboba]

Either I dreamed them into live, or they exist

I believe I've seen some special sleeves that when squeezed created washers

I have a DIY undertray made out of composite aluminium, and I want to add those double sided washers where the bolts holes are - this way when torqued, the undertray material doesn't get too squashed

Is there any DIY or designated products for this?

 

[BORING HOP YARD]

You could also cut some Aluminum or stainless fuel line to the correct length for the thickness of the undertray, you would now have spacers inside the hole of the undertray. In effect you would be tightening the washer to spacer and not crush you undertray.
Hope this helps

 

[samss]

Maybe an eyelet or grommet?

 

[juddspaintballs]

Rubber grommet with metal insert?
https://www.jegs.com/i/Be-Cool-Radiators/134/72004/10002/-1

 

[ItsNemo]

Are you thinking nutserts?

 

[mbatarga]

Every single washer I've ever used or seen had two sides (double sided) - so I have no clue what you're talking about.

 

[duc916]

In plastic and other composites "compression limiters" are used to allow for proper fastener torque without yielding the base material. I have not seen a DIY version, but all you need is a spacer and couple of standard washers. Or a insert washer and a standard washer, this version is easier to assemble.

 

[joe49]

Every single washer I've ever used or seen had two sides (double sided) - so I have no clue what you're talking about.

4 sides

 

[matt_i]

You can make the crush-limiters/compression-limiters on the lathe.

Its just a "top hat" with a clearance hole for the fastener. Choose length of the "top" to just trap the material, I'd say no more than .005-.010" interference. Can also add a thickness of something like HDPE or other elastomer to prevent rattles in the stackup. The softest material is going to get squashed the most.

 

[bored350]

It's sounds like you are asking for a pin style fastener that when tightened, causes the cylindrical section to flatten out creating a washer that compresses against the material it slides through. These tend to be more of a permanent solution though and you may benefit from a plastic push pin fastener that snaps into place and can be relieved when needed.

Sent from my Moto G (5) Plus using Tapatalk

 

[WoodsTruck]

Something like this get you started?

 

[Kevin54]

4 sides

 

[alfazer]

I've had motorcycles with something similar holding the radiator and oil cooler in place.

 

[joe_padavano]

I'm assuming what you want is something like a very short, large diameter pop rivet, where you pull the center mandrel all the way out. Something like a nutsert could be made to work if you cut the small diameter threaded part off after swaging, but that's both time consuming and a waste of material. Can't say that I've seen exactly the item you're looking for, at least not commercially available.

You can buy thin shell rivnuts in sizes up to 3/8". This might get you close after cutting off the threaded part.

 

[Bigblue&Goldie]

What's "composite aluminum" and why would it crush if it's properly backed, regardless of if there is a washer behind it?

 

[lukedwag]

Composite aluminum is a layer of aluminum with a plastic middle and another layer of aluminum on the other side. It's most typically used in architectural metal panels. The most common brand is Alucabond.

Try this link for the grommets we use to make these panels removable in certain applications

https://www.metalgrommets.com/catalog/long-neck-chemical-black-oxide-grommets-p-252.html

 

[Bigblue&Goldie]

Gotcha. Never heard it called that before.

 

[mbatarga]

4 sides

No, no, no. You've got the inside (1), the outside (2) - but the top and bottom aren't sides!

 

[PugetDude]

No, no, no. You've got the inside (1), the outside (2) - but the top and bottom aren't sides!

You also have the inside edge (3) and the outside edge (4)

 

[sberry]

How much you got to tighten it?

 

[joe49]

No, no, no. You've got the inside (1), the outside (2) - but the top and bottom aren't sides!

Nope, inside and outside face, the ID and OD.

 

[welder4956]

No, no, no. You've got the inside (1), the outside (2) - but the top and bottom aren't sides!

Why not? Top side and bottom side.

How many sides to a cube, or does the top and bottom not count either?

 

[bullnerd]

Composite means race car, race car means Dzus fasteners!

 

[toplessHO]

4 sides makes it a square

 

[joe49]

4 sides makes it a square

...or a rectangle, or a tetrahedron pyramid, or a washer

 

[Muckin_Slusher]

So you need those things that honda has on their fourwheeler fenders so the tightened up bolt doesn't squish (and crack) the plastic.