A corrosion resistant 6Mo alloy for high chloride environments

• 

  General and localized resistance to saltwater and chlorides
• Strength almost 2x's 300 series stainless
• 254 SMO Mechanical properties
• Strength and corrosion charts
• Availability and lead times
• 254 SMO fastener styles
• Datasheet for 254 SMO fasteners

254 SMO (1.4547) fasteners are made of a high-end stainless steel alloy that was developed for resistance to saltwater and chloride corrosion. This 6-Moly (6% Molybdenum) alloy has good localized corrosion resistance and 254 SMO 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 6-Moly 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

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 (1.4547) Chemistry & Specifications

254 SMO Specifications: UNS S31254, EN Number 1.4547

254 SMO Mechanical Properties

254 Tensile Strength Chart

254 SMO Sulfuric Acid Iso Corrosion Curve

254 SMO Seawater Corrosion

Crevice Corrosion Tests in Seawater: Percentage of Sites Attached

254 SMO Screws  

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 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 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 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 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)
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 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 Screws	254 SMO socket head cap screws are an ideal solution for safe, secure fastening in low clearance applications.	• ASME B18.3 • DIN 912 / ISO 4762 • DIN 7984
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 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 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 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	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	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	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 

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 Washers	254 SMO washers are available as a split lock washer style.	• ASME B18.21.1 • DIN 127 / ISO 7090 • DIN 6796 /  ISO 10690