Crush tubes

[Empty]

Is there a standard thickness on box section when crush tubes should be used.
Im using 3mm box and 5mm box, 5 mm box will have 12mm bolts and 8mm bolts and the 3mm box 8mm bolts.

Thanks

 

[colnerov]

I would use crush tubes for both those bolt sizes and wall thicknesses.

 

[Bornfree]

It depends on the loading of whatever your bolting to it and the size of the box and the position of the bolts through the box.

 

[Smallfry]

Unless the application is really lightweight, I would always use crush tubes, no matter how thick the wall is.

 

[Empty]

Thanks, crush tubes it is.

 

[BrokenBiker]

It depends on the loading of whatever your bolting to it and the size of the box and the position of the bolts through the box.

I assume it's for the trailer he is attempting to build

 

[Empty]

Yes. I apologies but there is going to be lots of questions.

 

[colnerov]

We've got loads of answers, some will have no relevance to the task at hand. But don't let that stop you asking.

 

[nickk]

I’ve made and fitted these for years,never knew they had a specific name,never stop learning.

 

[Dozzer]

Make sure the tubes have a good wall thickness, ideally needs to be same cross section as bolt.
used to fit lot of side steps and heavy duty tow bars to 4x4's and the kits would always come with crush tubes that did bugger all other than trap dirt!

 

[northwest]

What is a Crush Tube? What purpose do they serve?

 

[Dozzer]

What is a Crush Tube? What purpose do they serve?

and you get them injection moulding to stop plastic parts getting crushed, very common on plastic cam covers and air boxes. but they have the official name of compression limiters!! = https://www.trfastenings.com/products/catalogue/fasteners-for-plastic/compression-limiters

 

[julianthegypsy]

What is a Crush Tube? What purpose do they serve?

I was waiting for someone to ask!

 

[Dozzer]

you also get crush tubes/sleeves in Dana axles between the pinion bearings, and they are meant to be crushed so the name is not remotely confusing

 

[Keithmac]

you also get crush tubes/sleeves in Dana axles between the pinion bearings, and they are meant to be crushed so the name is not remotely confusing

That was first thing I thought of, crush tube or crush sleeve. One use only.

None crush sleeve sounds better for the OP or compression limiter as mentioned above.

 

[BrokenBiker]

you also get crush tubes/sleeves in Dana axles between the pinion bearings, and they are meant to be crushed so the name is not remotely confusing

In my mind, the thing OP is asking about is and anti crush tube, as it's only there to stop the box section crush under the tightening force of the nut/bolt

 

[Dozzer]

In my mind, the thing OP is asking about is and anti crush tube, as it's only there to stop the box section crush under the tightening force of the nut/bolt

Dont look at me. i didn't name them.

 

[BrokenBiker]

Dont look at me. i didn't name them.

To be honest I've always called them bolt sleeves anyway

 

[northwest]

Okay guys thank you, I get what they are now. I have always thought of them as bushes.

 

[Red'n'Black]

I found out what they were for when I put the cambelt cover back on the Subaru, whoever had it apart last had lost all the ones that go along the bottom edge, the bolts would only do up finger tight without crushing the plastic.

Fortunately I had the top ones to copy, some tubing roughly the right diameter, and a lathe.
How does anybody manage without a lathe?