LP4 rivet question

[Charles in SC]

Are LP4 rivets special in any way or are they just hardware store rivets?
I had to take out one of my baggage compartment floors and now need to put it back in. The plans call for LP4-3 rivets. I have some -4s but no -3s. I wondered if I can use the -4s or maybe go buy some hardware store -3s. The floor ribs and the floor material are only about .050 thick so it seems like to me that the -3 are kind of long (3/16 grip).
Thanks in advance!

[Mel]

NEVER use hardware store rivets in an aircraft of any kind!

Although LP4 rivets are not necessarily "structural", they DO meet a spec.

Hardware store pop rivets do NOT! They are typically made from floor-sweepings and do not meet any kind of spec.

dash 4 rivets may work and may not. Try some scrap of the same thickness as the floor/rib combination and see how tight they get. If they are repeatedly tight, then they should work fine.

[RVDan]

The LP 4 series is a retained stem type that uses the stem as a structural element when in shear. Hardware store pop rivets do not retain the stem and are very weak in shear.

[Charles in SC]

Thanks, that is the reason we ask questions. LP4-3s it is then. I have not ever used any thing other than aviation hardware but I see rivets called "commercial" rivets and have never figured out quite what they are or are used for.

[rvbuilder2002]

Originally Posted by Charles in SC

The floor ribs and the floor material are only about .050 thick so it seems like to me that the -3 are kind of long (3/16 grip).

I assume you mean the -4's? are kind of long, because the -3's are what would be correct.

The LP series rivets actually have the min. and max. grip length marked on them (the lines marked on the shank). If the material being riveted at least equals the distance from the manufactured head to the first line (when viewed with the rivet fully inserted but not yet set), the rivet is not too long and can be used. And, as long as the line furthest away from the manufactured head is still visible when the rivet is fully inserted but not yet set, the rivet is not too short and can be used.

In simple terms, if the thickness being riveted falls somewhere between the two lines embossed in the rivet shank, the rivet has a proper grip length.

[Charles in SC]

Thanks, I have not been able to find any specs on the LP4 rivets. I used -3s the first time I put the floor in because that is what the plans called for. I do not have a -3 to check with the lines. I have seen the lines but did not know what they were for. I only said that I thought the -3 would be kind of long because it is a 3/16 grip length. I do not have any way to know what the short end of the grip range is. I know that most 1/8 inch pulled rivets are available in 1/8 inch grip length and thought that would have been a better length choice.

[rvbuilder2002]

The 3/16 " spec is a max grip length, doesn't mean you can only rivet thickness of 3/16.
There is a minimum grip length also, as there is for most blind rivets. If there wasn't, all we would need is one long rivet for everything.
I don't remember the spec. but I think the minimum for the LP4-3 is some where around .035 - .040.

[Tony Spicer]

Originally Posted by Charles in SC

Thanks, I have not been able to find any specs on the LP4 rivets.

Here are the specs for the 4-X rivets.

For a quick tutorial on breakstem rivets, have a look here.

Note the difference between structural and non-structural rivets. I doubt you'll find any structural pulled rivets used in an RV.

Tony

[SHIPCHIEF]

I tried to find an alternate, or local source for these, but I seem to recall that VANs is the source, not expensive and quickly delivered.
I bought extra, and a good thing as I probably will be lifting the floor to move some wires pretty soon.

[bhassel]

I'd say Van's has them. The RV-12 uses more than 15,000 LP4-3's and a good number of LP4-4's.

Bob