Corrosion is an ever-present threat to many metal structures, particularly those located in marine environments such as offshore oil and gas facilities. Grade 316 stainless steel screws are widely used in the construction of such facilities and is being superseded by tougher, longer-lasting duplex self tapping screws. BS Stainless, based in Lancashire, is an independent stainless steel supplier offering these essential stainless steel tapping screws.
One of the key features of duplex self tapping screws is their exceptional hardness that prevents the delicate thread from damage. Using steel screws for pre-screwing is no longer necessary as only a punched or pre-drilled hole is necessary.
Duplex 318l (variously described as UNS 31803 and 2205) combines the benefits of ferritic and austenitic steel, producing a metal with a tensile strength higher than standard stainless steel. Composed mostly of iron, duplex also includes a high proportion of chromium (22%) with added nickel and molybdenum (5% and 3% respectively).
Other features and benefits of duplex self tapping screws are – increased protection against corrosion, reduced life-cycle costing, increased tensile strength and high PRE value. Available in full range of sizes, complementary washers can be supplied on demand.
