6-32 x 4 in. Round Head Slotted Machine Screws – Steel Zinc – 100qty
https://nsiindustries.com/product/6-32-x-4-in-round-head-slotted-machine-screws-steel-zinc-100qty/
These screws have finer threads than typical screws, requiring a pre-drilled hole and are perfect for joining metal parts in machinery and construction.