Stainless Steel Pipe Fittings

Manufacturing methods and product standards for stainless steel fasteners

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There are different types of stainless steel fasteners that provide different levels of corrosion resistance and strength. They are used in corrosive industrial and marine environments, equipment, construction and construction applications. These products are available in all stainless steel designs and are used to join other metals such as copper, aluminum, carbon steel and zinc.
The specifications for a particular fastener grade should be based on the required corrosion resistance, strength and material to be fastened. The fastener should have corrosion resistance comparable to or higher than the corrosion resistance of the metal to be fastened. Specific application guidelines should be consulted to determine the most appropriate grade of stainless steel. SSINA Design Manual: Stainless Steel Fasteners can find general guidance. Some application-specific guidelines are provided in the Additional Design and Specification Resources section.
Manufacturing method
Stainless steel fasteners can be manufactured by machining or cold heading. Machining is the oldest method of producing fasteners, and it still stipulates very large diameters and small production runs.
Cold heading is a more common method of production. It transforms the wire into the desired shape by applying sufficient pressure to plastically deform the metal into the mold and stamping cavity without preheating the material. The production of bolts, screws, nails and rivets is relatively cool, but special custom operations can also be carried out in this way. Cold heading can significantly increase the strength of 300 series stainless steel fasteners.
ASTM standard

ASTM International Standards for fastener materials and specific products (bolts, nuts, screws and bolts) are shown in the table below. There are general purpose and specialized standards for high temperature, high pressure and low temperature applications. It should be noted that stainless steel gaskets do not have ASTM standards.

ASTM Standard Title
A 193 / A 193 M alloy steel and stainless steel bolt material for special applications such as high temperature or high pressure service
A 194 / A 194M Carbon steel and alloy steel nuts (including stainless steel) for high or high temperature service or both bolts
A774 / A774M austenitic stainless steel joint (welded) for general corrosive service at low/medium temperatures
A951 / A951M Standard Specification for Wire and Stone Reinforcement
A 962 / A 962M fastener or fastener material or both are common requirements for any temperature from low temperature to creep range
A1082 / A1082M Standard Specification for High Strength Precipitation Hardening and Duplex Stainless Steel Bolts for Special Applications, Note: For all high strength duplex and PH stainless steel fasteners – any size
C1242 Standard Guide for Design, Selection and Installation of External Size Stone Anchors and Anchoring Systems NOTE: This means that the metal in contact with the stone should be 300 series stainless steel, but other materials may be used if moisture and plating corrosion are properly prevented. Copper and stainless steel are used for the cable tie. Specify 316 instead of 304 if there is a typical coastal or deicing salt exposure. In harsh high salt environments, it is recommended to use more corrosion resistant stainless steel.
F 593 stainless steel bolts, hex screws and studs
F 594 Stainless Steel Nut Specifications
F 738M stainless steel metric bolts, screws and studs, metric
F 788 / F 788M Surface discontinuities in bolts, screws and studs, inch and metric
F 836M Stainless Steel Metric Nut Specifications
F 837 / 837M Stainless Steel Hexagon Head Screw Specifications
F 879 / 879M stainless steel socket button and flat head skull head screw
F 880 / 880M Stainless Steel Socket Set Screw Specifications

Source: China Stainless Steel Pipelines Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)

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Pipe Fittings

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