Self drilling screws for metal - square drive countersunk head - drill point
Zenith Self Tapping Screws Countersunk Head Stainless Steel 10G x 32mm
M4.2 x 16mm Black Phillips Wafer Head Self Tapping/Drilling Screws (100/pack) | eBay
8 x 1-1/2" (1/2" to 1-1/2" Available) Hex Washer Head Self Drilling Screws, Self Tapping Sheet Metal Tek Screws, 410 Stainless Steel, 100 PCS : Amazon.com.au: Home Improvement