How time flies.  I built my kitchen cabinets 30 years ago.  Many of the drawer slide screws are loose in their holes, and cant be re-tightened.  I'm looking for a way to restore the fastener holes without losing the precise hole locations.

Your help is greatly appreciated

Mark
Seattle

Take out the screw, slice a matchstick in half lengthways, put it into the screwhole. Use a utility knife to cut off the excess length, pop the screw back in, making sure it goes in between the matchstick and the side of the hole. Tighten up. Done.

If the screw's still too loose, use both halves of the matchstick and align the screw so that it goes into the hole with the two matchstick halves either side of the screw.

Add a bit of wood glue to that and that screws never coming loose again!

I just replaced my entry knob with a passage leverset and my deadbolt with an Ultraloq U-Bolt Pro Wi-Fi Smart Lock deadbolt.  To make it easier for my wife who has vertigo to entry with her arms full.  The lock works with finger print print, wifi and key.  The new latch bolt had smaller screws than the previous so I inserted wooden skewers into the holes and nipped them flush and drove the new screws.  Didn't bother with glue as there will be no direct pull on the screws.  This lock is great as the latchbolt is tapered and drives the door to the weatherstrip.  I had to take my Milwaukee 12v die grinder and a double cut bit to relieve a little so the bolt could drive home. 

Quote from: woodbutcherbower on February 23, 2023, 04:40 PM

Take out the screw, slice a matchstick in half lengthways, put it into the screwhole. Use a utility knife to cut off the excess length, pop the screw back in, making sure it goes in between the matchstick and the side of the hole. Tighten up. Done.

If the screw's still too loose, use both halves of the matchstick and align the screw so that it goes into the hole with the two matchstick halves either side of the screw.

I'm going to suggest an alternative that I think will keep the hole alignment a bit better.  Take three tapered toothpicks, push them together into the stripped hole that has been filled with glue so that all three go to the same depth.  Tap them in lightly with a hammer.  Let the glue set up overnight, then cut off the excess with a very sharp chisel.  Redrill the pilot hole.  Rinse, repeat...   

I like the radial symmetry of three, but if in a hurry you can use thick CA glue and shoot it with accelerator.

Blum (undermount) drawer guides have about a hundred mounting holes in them, couldn't you just use alternate holes?
Of course without seeing what you have his is hard anyway.
As suggested, by @Lincoln you could already have "normal" screws in them, where switching to 5mm "dowel screws" (aka Euro screws or system screws) would easily solve it.

Toothpicks or match sticks are a tried and true method too, but might be a bit fiddly with multiple holes per drawer guide.
Drilling over-sized and plugging with a dowel works there too, but could potentially give you realignment issues when reassembling. You would have to be much more careful to get them back where they were, since the original hole is "gone".

Of course this all assumes undermount, which is why most people would call them by the brand name of Blum. If you mean simple white epoxy coated 3/4 extension "kitchen cabinet" guides, some of this will not apply. Mostly my comment about multiple holes, the other plugging solutions still apply, as will the 5mm screws. Even the cheapest models today have holes that will accommodate either style screw, I don't know about 30 years ago though? In the US, maybe not? but Blum, definitely yes.

I'd clean up the bad holes with the correct size drill bit, then glue in the correct size dowel and redrill the pilot hole with the correct size Vix bit.

Here's something similar done on an outside door frame that had too many trim screw holes.

As a commercial locksmith, I've some interesting repairs over the years.  After installing an automatic operator on an exterior pair of doors at an assisted living complex, they asked me if I could repair the interior pair of "oak" doors.  The jambs seemed flimsy and the hinge screws would not hold.  I removed the face trim to find that the jamb was not supported by a stub, instead had intermittent blocking only which explained the doors touching at the tops.  Installed studs and was onto the doors themselves.  The "oak" doors were veneered MDF and the edge was only 1/2" oak and the screws were stripped.  I took the doors back to my shop and for each of the 12 hinges screw I drilled a 1/2" hole 4" deep and installed maple dowels.  That was more than 25 years and those doors are still hanging.

The correct Pozi-driv bit will bring you joy. Wrestling with a Phillips 2 is generally an exercise in frustration.
They are bad enough with Phillips screws, and don't engage deep enough in PZ screws. If you spin one and round it out, they can be a real pain to remove.