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SS 309 Fasteners, also known as alloy 309, is austenitic steel. It is specially formulated to work in high temperature and corrosion resistance environments. However, even though the unmatched quality of working in high temperatures persists, it is still not recommended in high carburizing atmospheres.
This alloy is a composition of various elements that are listed below :
• Nickel
• Chromium
• Carbon
• Manganese
• Phosphor
• Sulphur
• Silicon
• Iron
All these elements combined are used to produce SS309. Sulphur and nickel are added in a lesser percentage compared to other elements. Chromium is the dominant element as the percentage of it is the highest in the production of SS309.
Properties of SS 309 Fasteners:
Stainless steel 309 is generally used in works that are performed in extremely high temperatures. Its high content of nickel and chromium makes the fasteners resistant to corrosion and super resistant to oxidization. These fasteners are used in rough construction because of its high durability and resistance power. The dimensional precision of SS 309 is high, which gives the fasteners an extra efficiency compared to other stainless steel grades that do not possess this quality. The low amount of nickel in fasteners material makes it immune to sulphur attacks at high temperatures. It is also utilized in cementing and thermal cycling applications, but care is taken by reducing the service temperature.
Properties of SS 309H Fasteners:
Stainless steel 309H is added large carbon quantity to obtain higher creep strength. It reduces its malleability, but the increase in strength is exceeded to SS 309 grade. As mentioned above, it works well in elevated temperatures. It can also be quenched very fast. The only thing we need to take care of is that the post-annealing has to be done to restore its corrosion resistance property.
Industrial uses of SS 309/ SS 309H Fasteners in:
These fasteners are used in the generation of different purposes in different areas.
• It is used in furnaces, including parts like burners, piping.
• It is used mainly in paper-making equipments.
• It is also used in power generation ( pulverized coal burners and tube hangers).
• Effective use of SS 309H fasteners is seen in petrol refining.
• Thermal processing
• Used in waste treatment equipments (rotary kilns, calciners and incinerators).
Standard | ASTM F593, F594, F1554 / ASME SF593, F594, F1554 |
Bolt / Screw Size | M3 – M56 | 3/6″ to 2″ | Custom Sizes |
Nuts Size | M3 – M56 | 3/6″ to 2″ | Custom Sizes |
Washers Size | M3 – M56 | 3/6″ to 2″ | Custom Sizes |
Machine Screws Size | M1.6 – M12 |
Self Tapping Screw Size | No.2 – No. 14 |
Length | 3 mm to 200 mm |
Studs, Bolts, Threads | UNF, BSW, BSF, METRIC, UNC, or as required |
Threads Configuration | ASME B1.1 2A/3A – 2B/3B Inch Unified Threads and B1.13M 6h-6G Metric Coarse Threads |
Certification | Dual Certified As per ASTM & ASME Codes |
Dimensions | DIN 931, 933, 934, 7991, 976, 125, ASME B18.2.1, B18.3 |
Threads | Unless otherwise specified, the threads shall be rolled or cut and tapped horizontally or vertically |
Test Certificate of Bolting | as per EN 10204 / 3.1 Manufacturer Test Certificate |
STANDARD | WERKSTOFF NR. | UNS | JIS |
SS 309 | 1.4828 | S30900 | SUS 309 |
SS 309H | 1.4833 | S30909 | SUS 309H |
Grade | C | Si | Mn | P | S | Cr | Ni | N |
SS 309 | ≤ 0.20 | 1.50-2.50 | 2.00 | 0.045 | 0.015 | 19.0-21.0 | 11.0-13.0 | ≤ 0.11 |
SS 309H | 0.04 – 0.10 | 1.0 max | 2.0 max | 0.045 max | 0.030 max | 22.0 – 24.0 | 12.0 – 15.0 | – |
Hardness HB 30 ≤ HB | 0.2% Yield strength Rp ≥ N/mm² | Tensile strength Rm N/mm² | Elongation A5 ≥ % | Resistant on air up to °C | Modulus of elasticity kN/mm² |
223 | 230 | 500-750 | 30 | 1000 | 196 |