Door handle baby screws - what size?

[Jeremy]

Help please. I'm reassembling the outside door handles that have just been replated. Lovely plating job but I need to clean out the threads for the 2 little screws (see photo) that secure the cap for the lock mechanism in place. Anybody know what size and thread these screws are? I make them 40 TPI and a O.D. of about 0.115 inch. Would it be a UNC thread as it's Mazak alloy?

Many thanks as always,



(Plating done by Marque Restore. Bumpers, window frames, trims, spinners, the lot. Very good quality indeed. One of the spinners had the centre stoved in and they pushed it back into shape so well that you cannot tell which one it was. 5 stars)

[abowie]

I thought they were self tappers.

[JagWaugh]

#4-40 would be 0.112 and 40tpi. 40 tpi might not seem coarse, but it is.

Try running a toothpick in to check the pitch with your thread pitch gauge. (You have a thread pitch gauge, right?)

[Jeremy]

Thanks JagWaugh. Definitely 40 TPI using my thread gauge. (The gauge is marked V-US-AMER-NAT which I think means unc/unf profile.)
However checking again the screws are slightly triangular in cross section, so the diameter measures 0.110 + or - a few thou. So I assume that means they are also self tappers Andrew...the screw heads are butchered so I will look for some identical replacements, or failing that get a #4-40 tap and normal screws.
Many thanks both,