Generally, people ask the question, what’s the distinction between 18-8, 304 and 316 stainless steel nut and bolts, for the reply to this question, you must first know some basic information regarding stainless steel nuts and bolts.
“Stainless Steel” is the general name for a large family or group of alloy steels that contain at least 10.5% chromium as part of the composition. At and above this amount of chromium, an intricate chrome-oxide surface layer creates that prevents additional oxygen atoms from penetrating into the steel and so protects the iron in the matrix from rusting and corrosion in a bolt or a nut.
This layer is what makes the bolt”stainless” Higher levels of chromium and the inclusion of other alloying elements such as molybdenum and nickel improve this protective barrier and further enhance the corrosion resistance of the stainless steel the popular grades in hex nuts and bolts, foundation bolts, anchor bolts, nuts & bolts, Nut & bolts in stainless steel being SS 316 and S 316L and 316S31.
You can also get more additional info about ‘all types of pipe fittings, stainless steel valve’ (which is also known as ‘รวมข้อต่อท่อทุกชนิด เหล็ก สแตนเลส วาล์ว ราคาประหยัด‘ in the Thai language) from online websites.
There are lots of distinct kinds of stainless steel fasteners or bolts and nuts, but by far the most popular and widely used are the 300 series stainless sheets of steel, also referred to as the austenitic stainless steels.
The 300 series designation comprises many diverse compositions of metal steel bolts and nuts and attachments (303, 304, 304L, 305, 316, 321, 347, 316S31, 316Letc.) Nevertheless, the common factors among them are:
Their carbon material is usually held to a maximum of 0.08percent
They (generally) have 18% chromium
They (generally) have 8 percent nickel
They can’t be hardened by heat treatment
They can be hardened by cold working the substance (“work hardening.”)
Undoubtedly the second most popular sort of stainless steel bolt and nuts or screws or fasteners, after Type 304, is Type 316. In Type 316 stainless steel nut and bolt & washers SS 316 Nut and bolt, the chromium content is reduced from 18% to 16%, but the nickel content is increased to 10% and 2% molybdenum is added into the mix.
This shift in the chromium/nickel ratio and the inclusion of the molybdenum increases the resistance to chlorides. This is the reason Type 316 stainless steel nut and bolt is commonly utilized in more corrosive environments where the material will be subjected to chemical, solvent, or salt water corrosion and makes it the preferred material for marine construction.
The current use of 316S31 grade nut and bolt & washers in marine software and sewage plants and offshore applications from the west has improved the performance of the bolt, and it has given a longer life to the products life cycle.