poetman

I just installed a rear rack on my rear fender, but the nuts that used to fit on the rear stays no longer have any threading with the rear rack installed. Is this normal, or did I install it improperly--which doesn't seem likely. They're
Not rocket science. The bike is a Raleigh Sports, and the rack looks like this:

FBinNY 

Do you mean you need longer screws? They exist, remove one of yours, figure out how much longer you need and go to the hardware store. BTW the thread is usually metric 5x.8mm, but if you bring the screw they can match.

WARNING - There's an American size, 10-32 which is very similar and can be confused easily. Problem is it'll fit but be sloppy and can strip the frame when tightened.

MichaelW

It is best to put the rack stays next to the frame, and fender stays outermost, otherwise a loaded rack has leverage on the bolts.
Does the frame have threaded bolt holes, most do, but some older ones don't.
If you have threaded eyelets, use a good quality allen bolt, long enough for rack, fender, washer, with about 2 threads exposed at the tip of the bolt.
If your holes are unthreaded, you need longer bolts and some nylock nuts. If the chain runs close to the frame, it may catch the nut, in which case, use a flat-head bolt, feed in from inside and use the nut on the outside.
Smear a little grease on threads before fitting.

jimc101

How do you do that?

The fender stays will be in conflict with the rack if you do it that way, the fender stays have to go on the inside, as the fender stays will bend inwards

Andrew R Stewart 

The English Raleigh Sports 3 speed bikes used 5mmx.9mm threaded eyelets. Not a common size these days but the M5 (.8mm pitch) will fit and work well enough in the few threads that the drop outs have. But using a backing nut on the bolt (and it is called a bolt) is a really smart idea. As others have said a longer bolt should be readily available from a number of sources. Since we don't know where the OP lives we can't say if there are any LBSs near by.

We also don't know if the rack is a real Pletcher brand or an Asian knock off. Not much difference for the fit but the Asian versions don't have the same reliability. These racks are considered to be of the light weight variety. While pannier bags or baskets will mount to these racks the lack of vertical bracing and any triangulation makes for a flexible platform. Think of the tail wagging the dog if there's a lot of weight on these racks. Andy.

MichaelW

Here is a pic of a mounting order: frame/fender/rack.
This one is setup frame/rack/fender.

The latter is much more secure for rack mounting, less stress on bolts and less movement of rack.
Fender stays are not loadbearing and work equally well with both orders.

HillRider

For many bikes, the drive side fender/rack eyelet must not have the bolt protrude too far to the inside or the bolt may keep the chain from shifting to the smallest cog. So, there may not be room for a nut on the inside. Since you can't add a nut, Locktite 243 is probably a good idea for this bolt. A work-around is to use a thin head bolt and insert it from the inside and use a nut on to outside to fasten the fenders and/or rack.

poetman

The rack is Pletcher brand--if it matters. It seems like the bolts thread through the fender stays as well. The rack and fenders feel secure without the nut, but it seems you all think I should get a longer bolt that would fit a nut. So, I need to look for an 5x8mm metriC bolt? Also, it didn't seem like the rack would mount on the inside of the stays, so it's currently on the outermost portion of the bike. I thought the fender stays on the inside would keep the bike more authentic to its original placement. Is this more secure?