Loads more being listed so take a look if you need different sizes.
eBay
M5 Thumb Screw No Bolt Nut for Action Camerar for GoPro Hero DJI Action Insta360 Cameras Short/Long Tripod Mount Adapter Screw
Aliexpress UK
8 BA Brass Countersunk Machine Screws Manufactured by EKP Supplies in The UK. EKP supplies.
eBay
Quick Release Screw 1/4-20 3/8-16 Inch Tripod Mount Adapter ballhead Camera Quick Release Plate Screw Photography Accessories
Aliexpress UK
Loads more being listed so take a look if you need different sizes.
eBay
2Pcs Microphone Clip Adapter Screw of 3/8 to 5/8 Screws Mic Bracket Tripod Converter Instrument Accessories Microphone Parts
Aliexpress UK
4 BA hex head screws available in various lengths.
eBay
50/10pcs Cross Round Head Screws M2 M2.5 M3 M3.5 M4 M5 M6 M8 A2-70 304 Stainless Steel Phillips Round Pan Head Screw Bolt Dia2-8
Aliexpress UK
Thread size: 6BA - 0BA. With a slotted countersunk head. Solid brass BA machine screws. We also have listed various other sizes and head shapes.
eBay
Hex Head Self Drilling Screws, 410 Stainless Steel Self Tapping Sheet Metal Tek Screws 100pcs
Aliexpress UK
This is a set of 3BA (British Association) slotted cheese head screws, made from zinc plated steel. They are available in the following lengths Not what you want?.
eBay
M14 Car Sealing Gasket Aluminum Screw Washer Auto Engine Bottom Oil Drain Screw Sealing Gasket Accessories for Honda 94109-14000
Aliexpress UK
Loads more being listed so take a look if you need different sizes.
eBay
Hex Socket Screw Kit DIN912 Black Grade 12.9 Carbon Steel Hexagon Round Cap Allen Bolt Nut Washer M2 M3 M4 M5 M6 Machine Screws
Aliexpress UK
5 BA Steel Round Head Machine Screws Manufactured by EKP Supplies in The UK.
eBay
Surveying Instruments General Accessories Theodolite/Total Station/Level Tripod Accessories/Center Screw/Screw
Aliexpress UK