ForceTec Rivetless Nutplates

[utspg1980]

Anyone familiar with these? I've been in initial contact with the company and of course they make them out to be the greatest thing since sliced bread. Just wanted to see if there was any outside input on these.

Despite the fact that they advertise them heavily for fatique improvement, we are interested in them more for corrosion prone areas. Also areas where we have a stackup of many materials. A mechanic trying to drill out an .098 rivet thru 1" of material to replace a nutplate has cost us dearly in the past.

 

[rb1957]

i Hate bonded a/nuts ... but then these guys swage into the screw hole don't they ?

'cuse me for saying, but why the heck are you installing an a/nut through an 1" of Al ??if the nut's stripped, add a new nut on a separate nutplate, preferribly riveted to a stringer standing flange, maybe add a couple rivets (with a reasonablt t/d), or last resort, use a couple existing structural fasteners (R&R them)

 

[bf109g]

rb -

Unfortunately, there are stupid people working at places like Goodrich and Boeing who like to trap nutplate fasteners in fairly thick stackups in their designs. In some cases, the only way to get at the countersunk head is to drop the engine and part of the pylon. Brilliant.

 

[WKTaylor]

utspug 180...

The FTI Rivetless NP really needs to be designed-in. Retrofitting this design to a existing NP install is hard/impossible, as we found-out recently. Value would be self evident in a new design. Adequate EM, CXed, reinforced and sealed hole, etc... many good things from the beginning.

CAUTION:

The Starting hole is fairly large, relative to the bolt dia. Many existing designs will not tolerate the reduced EM.... especially if EM is less than ~1.5-D.

Also, if an existing reduced rivet spacing NP is/was installed the rivet holes are too close to the NP rivet hole to salvage (enlarged center hole and rivet holes are ~1-D EM, or less.

If an existing standard rivet spacing NP is/was installed, then the NP rivet holes should be CX and rivet-plugged before installing the rivetles NP: otherwise the OS center hole and the CX deformation will distort/deform the rivet hole.

Make sure you plan corrosion protection for the disimilar materials.

Regards, Wil Taylor

 

[graemew]

Gooday utspg 1980 and Wil,
I have looked at the Forcetec nutplate a numner of times in the past for resolution of a number of problems but the biggest issue has always been the closeness of the anchor nut rivet holes. According to Len Reid at FTI, it is necessary to cold work those as well (normally) prior to plugging with rivets so that the entire installation is surrounded by a zone of compression stress in which short EM has no significant effect. It sounded good at the time but I never did see any FTI reports that would support such a contention. Len is pretty reliable though, so of he says it is so, then the reports probably exist.
I don't know what you do if you cannot get at the rivets though.
I would suggest that you contact FTI and see what they say about your problem. They love this sort of thing (Len will probably crucify me for saying that).
Regards
graemew