The 'Self Drilling Screw for Metal' or 'Stainless Steel Tek Screw' is a screw designed to self-drill into metal. There are several material types available and they each have their strengths and weaknesses. Why does the grade matter? Getting the material right for your application is critical. Some Stainless grades have excellent corrosion resistance (304 and 316) but are relatively soft and will not self-drill through much more than thin aluminium. Other grades like 410 are heat treated and have excellent hardness - but anywhere near salt-water (or any sort of coastal atmosphere) and you will see some tea-staining pretty quick! Some Stainless grades such as Hardtec and Marutex offer the benefits of both (hardness and excellent corrosion resistance) - but are only available in Hex Washer Face Head style. Getting the right material grade and screw type for your application is critical. Stainless Steel Self Drilling (Tek) Screws - so what is available? The Stainless Steel...