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Rivnuts in thin sheet?
tegwin - 25/1/16 at 11:50 AM

I am using a rivnut tool and inserts for the first time at the moment. Some really useful applications but I am having problems getting them to bite properly in thin steel.

Is there a trick to getting steel (M6) inserts to correctly bite in metal that is 1-1.5mm thick?

Using them to secure bits and pieces into the bodywork of my van conversion.


loggyboy - 25/1/16 at 11:56 AM

Washers?
Bonding of some sort?

[Edited on 25-1-16 by loggyboy]


tegwin - 25/1/16 at 11:58 AM

The problem is the nutsert needs to be flush with the panel and its a big hollow box section on the chassis so I can't get to the inside of it


Doctor Derek Doctors - 25/1/16 at 12:03 PM

I've never had any problems getting Rivnuts to grip in thin sheet.

I always use the type with a bigger head (not the counterunk ones) and the ones with a knurling on the outside so they can grip better. I always think that the smooth bore ones are going to lose grip no matter what you do.

Are you drilling the hole the right size? I always go for "only just big enough" so that the knurling can grip well. Also I assume you are pulling them up tight enough?


adithorp - 25/1/16 at 12:12 PM

I'd agree with what DDD said. I had issues with plain rivnuts so only use the knurled ones now. I use the small head ones but don't counter sink them as I found that in thin sheet can push through; Although close, they are never completely flush as a result.


nick205 - 25/1/16 at 12:14 PM

As above, my experince has been with the knurled rivnuts which gripped well in 1.5mm wall box section steel. Make sure the holes are only just big enough for you to force the rivnut into to ensure a good bite and be careful not to over tighten the bolt you put into it.

Out of interest, what are you using to squash the rivnuts? IMHO the way they are deformed into the panel must affect how well they bite.


nick205 - 25/1/16 at 12:50 PM

The reason I ask what tool you're using is that I tried an attachment for a pop rivet gun, which didn't work well. I subsequently used a purpose made tool from MK, which clinched the rivnuts very well and was easy to use.


MikeRJ - 25/1/16 at 12:58 PM

Are you using the correct rivnuts for the job? There are multiple different sizes that each accommodate a limited range of panel thickness's.

Using the correct tool is important as well. Trying to fit them using a nut, bolt and washer doesn't work very well IME.

[Edited on 25/1/16 by MikeRJ]


tegwin - 25/1/16 at 01:33 PM

Interesting replies thanks chaps.

Im using a "proper" rivnut tool. I struggle to squeeze it on 6mm... Perhaps if I reduce the inserts to 5mm I might be able to squash them a bit better.

I will look into getting some knurled ones and see how that works out.


Doctor Derek Doctors - 25/1/16 at 02:18 PM

quote:
Originally posted by tegwin
Interesting replies thanks chaps.

Im using a "proper" rivnut tool. I struggle to squeeze it on 6mm... Perhaps if I reduce the inserts to 5mm I might be able to squash them a bit better.

I will look into getting some knurled ones and see how that works out.


I have the hand tool and M6's are a bit of a struggle to squeeze, it makes your hands strong though!

Do you really need M6? Unless its something really heavy or under a lot of strain M4/5 is usually enough.


tegwin - 25/1/16 at 02:21 PM

True, I can just use more of them..


Im fitting an alloy "L" section down one side which will support one side of the bed so I don't want it to fail at an..urm... inapropriate moment...


nick205 - 25/1/16 at 02:50 PM

Lie still and you'll be fine ;-)


prawnabie - 25/1/16 at 03:04 PM

If this vans a rocking....its not long before the bed support breaks!


bi22le - 25/1/16 at 07:35 PM

Dont come knockin' if the rivnuts are poppin'!!

That changed tone quickly.

By the way, i hate rivnuts.


tegwin - 25/1/16 at 08:06 PM

I can see why, Once the bolt corrodes in there's going to be little chance of undoing them if the rivnut rotates... Almost tempted to weld some captive nuts to the body... Hmm


ashg - 26/1/16 at 04:32 AM

i had the hand rivnut tool, i always thought it was hard work and usually the thread never ended up straight in the center of the hole. i got one of those memfast tools, wasn't that cheap and its not super fast in operation put it puts them in perfectly every time with very little effort.


owelly - 26/1/16 at 10:59 AM

Use Sikaflex along with the Rivnuts. It's strong enough to withstand the weight without the Rivnuts......


907 - 26/1/16 at 12:27 PM

Description
Description




This is the back view of a zinc plated M8 knurled Riv Nut in a scrap of 1mm mild steel.


Does the back of yours look anything like the tight rounded rib that has formed and gripped the edge of the hole ?


If not, then it's an insertion tool error, i.e. you bought the wrong one.


Paul G