Hey @LL211 ,
I have had a look at this and you will need 4 M4 screws (26-28 mm). Find more about this on page 12 in this manual: https://downloadcenter.samsung.com/content/EM/202003/20200325140559228/BN68-10528E-00_UM_UT5300L_UT4...
I returned the TV to the retailer for a full refund and bought a new one (Sony). It was simply ridiculous!!!
(When I had the Samsung I also bought two new sets of screws that were recommended on this forum but neither of them fit properly.
Bought same. It is an M4 x 28mm. Fits perfectly, its the same thread we use in Beezer boxes. Screwfix will sell them. Suggest you use the multiple snap off length ones.
hi I had same problem no threaded screws fitted so I used no nails to stick the bracket to tv then carefully used self tappers taking care of the depth you go to .A disgrace by Samsung they say m4 fits !!