Corrosion protection for high chloride environments

254 SMO fasteners are made of a high-end stainless steel alloy that was developed for resistance to saltwater and chloride corrosion.  In addition to its good localized corrosion resistance, 254 SMO also provides much higher strength than other austenitic stainless steels. 254 SMO bolts are an ideal choice for high chloride environments including brackish water, seawater and other applications that demand heavy use of chlorines and chlorides. Compared to sister alloy AL6XN, 254 SMO fasteners offer slightly less high temperature stability corrosion resistance and strength.

Key Attributes
•  Good resistance to pitting & crevice corrosion
•  Good resistance to stress corrosion cracking
•  Good general corrosion resistance
•  Good strength nearly twice that of 300 series steels
•  High ductility and impact strength
•  Low carbon content for reduced risk of carbide precipitation during heating

Applications
•  Often used in industries that require bleach such as pulp & paper
•  Seawater protection for off-shore oil
•  Saltwater applications such as desalination
•  Chemical and food processing equipment
•  Flue-gas cleaning and desulfurization scrubbers

Resources: Flange DimensionsFlange Bolting Chart


254 SMO Fastener Availability

Availability
Extreme Bolt & Fasteners offers 254 SMO screws, nuts and washers in many styles, as well as other threaded products. We have a minimum order quantity of appoximately 20 pieces for most fasteners. The typical lead time for 254 SMO fastener production is 3-4 weeks, depending on the complexity and quantity. 

  • Diameter sizes:  Standard #00 – 4” in diameter / Metric M1.2 – M48
  • Threads: UNC, UNF, UNJ, UNR, Rolled,and Cut
  • Custom to print available.
  • ASTM, ASME, MIL specifications, DFAR and Domestic available

Expediting Options
Expediting options are also available upon request. When submitting a quote, please let us know your required lead time so that we can do our best to accommodate your specific needs.


254 SMO Fastener Styles

254 SMO Screws 12 Point ScrewsButton Head Cap ScrewsFlat Head ScrewsHex Head Cap Screws, Pan Head Screws, Security Screws, Set ScrewsSocket Head Cap Screws, Vented Screws
•  DIN 603 / ISO 8677
•  DIN 912 / ISO 4762
•  DIN 913 / ISO 4026
•  DIN 914 / ISO 4027
•  DIN 915 / ISO 4028
•  DIN 916 / ISO 4029
•  DIN 921
•  DIN 931 / ISO 4014
•  DIN 933 / ISO 4017
•  DIN 961 / ISO 8676
  •  DIN 965 / ISO 7046
  •  DIN 966 / ISO 7047
  •  DIN 7991 / ISO 10642
  •  DIN 7380 / ISO 7380
  •  DIN 84 / ISO 1207
  •  DIN 85 / ISO 1580
  •  DIN 34822
  •  DIN 34821
  •  DIN 7504 / ISO 15480
  •  DIN 7984
  •  DIN 963 / ISO 2009
254 SMO Bolts Hex Head Bolts, Shoulder Bolts •  DIN 931
•  DIN 933
•  ISO 4014
•  ISO 4017
•  ISO 7370
254 SMO Nuts Hex Nuts, Lock Nuts •  DIN 439 / ISO 4035
•  DIN 934 / ISO 4032
•  DIN 985 / ISO 7040
•  DIN 986
•  DIN 980 / ISO 7042 / ISO 19513
•  DIN 6923 / ISO 4161
254 SMO Threaded Products  Studs, Threaded Rods •  DIN 975
•  DIN 976
254 SMO Washers Flat Washers, Lock Washers •  DIN 125 / ISO 7089 / ISO 7090
•  DIN 126 / ISO 7091
•  DIN 127 / ISO 7090
•  DIN 9021 / ISO 7093

254 SMO Chemistry & Specifications

254 SMO Specifications: UNS S31254, EN Number 1.4547

Chemical Composition 254 SMO


254 SMO Mechanical Properties

254 SMO strength chart

254 Tensile Strength Chart

254 SMO Tensile Curve

254 SMO Sulfuric Acid Iso Corrosion Curve

H2SO4 Iso corrosion curve

254 SMO Seawater Corrosion

Crevice Corrosion Tests in Seawater: Percentage of Sites Attached

Crevice corrosion Seawater EBF version


254 SMO Screws  

12 Point    12 Point Screws 254 SMO 12 point screws are ideal when you need higher torque than socket head cap screws offer. These screws are available in 1/4" diameter or larger. The only drawback is 12 point screws are less economical and require a higher minimum quantity due to the complexity of production. •  IFI-115
•  MIL SPEC
•  DIN 34822
•  DIN 34821
Button Head    Button Head Cap Screws For applications that require a wide clamping area and low profile fastener 254 SMO button  head cap screws are a good choice. Button head screws are also used for fastening a material that is too thin to counter bore. • ASME B18.3
• ASME 18.3.4M
• DIN 7380 / ISO 7380
Flat Head 3D    Flat Head Screws 254 SMO flat head screws come standard with an 82° countersink angle. Other angles ranging from 60° -120° can also be made upon request. 254 SMO flat heads can be made with slotted or socket drivers. Phillips, torx and tamperproof drivers are also available depending on size, quantity and material. •  ASME B18.3
•  ASME B18.3.6
•  DIN 963 / ISO 2009
•  DIN 965 / ISO 7046
•  DIN 7991 / ISO 10642
Hex Cap Screw    Hex Head Cap Screws 254 SMO hex head cap screws are one of the most commonly used styles. They feature an added washer face that hex head bolt do not have. This washer face provides tighter dimensional tolerances. 254 SMO hex head cap screws provide high clamping force and easy access. • ASME B18.6.3
• DIN 931 / ISO 4014
• DIN 933 / ISO 4017
• DIN 961 / ISO 8676
pan head screw s    Pan Head Screws Pan head screws have a rounded head and most commonly have a slotted driver. 254 SMO pan heads are best for small diameter and low torque applications. • ASME B18.6.3
• DIN 7985
• DIN 921
• DIN 85 / ISO 1580
• DIN 84 / ISO 1207
  (cheese head)
• DIN 966 / ISO 7047
  (raised counter sunk)
SecScrew Drives   Security Screws 254 SMO tamper-proof security screws provide protection from unwanted removal because they cannot be unfastened using an common driver. Tamper-proof screws are produced in a wide variety of head styles, as well as custom per print.  
Set Screw    Set Screws 254 SMO set screws are a headless fastener with a slotted or socket driver on one end and a special tip on the other. Set screws are available with cup, cone, flat, dog and half-dog points. • ASME B18.3
• DIN 913 / ISO 4026
• DIN 914 / ISO 4027
• DIN 915 / ISO 4028
• DIN 916 / ISO 4029
Socket Head Cap Screw Short Image     Socket Head Cap Screws 254 SMO socket head cap screws are an ideal solution for safe, secure fastening in low clearance applications. • ASMET B18.3
• DIN 912 / ISO 4762
• DIN 7984
Vented Screw Main Image short    Vented Screws 254 SMO vented screws provide a way to out-gas application contaminents through a vertical hole drilled from the screw head through the threaded shaft. Vented screws are ideal for vacuums / high vacuums. Nimonic vented screws are available a variety of head styles.  

254 SMO Bolts 

Hex Bolt    Hex Head Bolts 254 SMO hex head bolts are similar to hex head cap screws except without the washer face under the head. Hex bolts are a good choice when high clamping force needed for easily accessible applications. • ASME B18.2.1
• DIN 931 / ISO 4014
• DIN 933 / ISO 4017
Shoulder Bolt    Shoulder Bolts 254 SMO shoulder bolts have a head, smooth shoulder (for rotating parts) and botttom threaded segment. Shoulder bolts typically have a socket driver. • ASME
• DIN 7379 / ISO 7379
• ISO 7370

254 SMO Nuts 

Hex Nut       Hex Nuts 254 SMO hex nuts are available in the followin styles: finished hex nuts, jam nuts and heavy hex nuts. • ASME B18.16.3
• ASME B18.2.2
• DIN 439 / ISO 4035
• DIN 934 / ISO 4032
• DIN 986
Lock Nuts       Lock Nuts 254 SMO lock nuts are availalbe in all-metal and polymer/nylon insert styles. All-metal lock nuts such as stover and flexloc are ideal for high temperatures and even load distribution. 254 SMO nylon insert lock nuts are more economic but should only be used when temperatures are under 350°F. • ASME B18.16.3M
• DIN 980 / ISO 7042 / 
   ISO 19513
• DIN 6923 / ISO 4161
• DIN 985 / ISO 10511 /
  ISO 7040

254 SMO Studs & Threaded Rod 

Studs    Studs 254 SMO studs are threaded sections of rod less than one foot in length. They can be fully or partially threaded (such as double ended studs) and are available in any custom length. • ASME B18.31.2
• DIN 976
Threaded Rod 2    Threaded Rod 254 SMO threaded rods are available in any custom length greater than 1 foot. The minimum order quantity for threaded rod is 6 feet of total length (for example 2, 3-foot pieces) and our maximum shipment length is 6 feet. • ASME B1.1
• DIN 975

254 SMO Washers 

Washer      Flat Washers
254 SMO washers are availble in several specifications including SAE, USS, DIN, MilSpec, oversized, and custom per print. • ASME 18.21.1
• SAE / USS
• DIN 125 / ISO 7089 /
  ISO 7090
• DIN 126 / ISO 7091
Lock Washer      Lock Washers
254 SMO washers are available as a split lock washer style. • ASME B18.21.1
• DIN 127 / ISO 7090
• DIN 6796 /  ISO 10690

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