McMaster 95893A233 Flat Head Thread-Forming Screws for Plastic, 18-8 Stainless Steel, Torx Drive, M4 Screw Size, 10 mm Long, Pack of 25

Drivers won’t slip out of these corrosion-resistant screws, which form threads in plastic to secure components with countersunk holes. Also known as star drive, the six-lobe Torx recess withstands more torque than slotted, Phillips, or hex drives. Screws press threads into molded or cast holes without cracking or distorting the material. Use them to fasten plastic components, enclosures, and panels. Their flat, beveled head sits flush in holes.

Length is measured from the top of the head.

18-8 Stainless Steel—The choice for wet and outdoor environments. However, these screws won't hold up to the harsh chemicals that 316 stainless steel can.

Round Shank — The sharply angled threads drive into plastic with less force and a lower risk of cracking than other tapping screws. The base of the threads is recessed to bite deep into material and hold tight. You can reuse these screws a few times without stripping the threads. They're comparable to PT screws.