Duplex Fasteners - Bolts, Nuts & Screws

Engineered stainless: 2x stronger yield than 316 stainless steel

·         Decent general corrosion & cracking resistance

·         Chemistry & Specs: Duplex 2205, Super Duplex 2507, Zeron 100

·         ASTM A1082 fasteners

·         Insight on Duplex 2205, Super Duplex 2507 and Zeron 100

·         Strength Properties: tensile, yield & elongation charts

·         Duplex stainless steel fastener styles

·         Fastener availability and lead time

·         Datasheet for Super Duplex 2507

·         Datasheet for Duplex 2205

Duplex Fastener Overview

Duplex 2205 and Super Duplex 2507 (UNS S32205 / UNS S32750) stainless steel fasteners are characterized by their high yield strength, which is twice that of annealed austenitic stainless steels, like 304 and 316. In addition, Duplex steels offer improved corrosion protection compared to 300 series stainless, especially in terms of localized corrosion such as crevice and pitting, as well as stress corrosion cracking.  In general, Duplex steel bolts are a great step up from 300 series stainless.

Mechanical PropertiesDuplex 2205 bolts provide a typical UTS of 110ksi and a yield strength of 80ksi, whereas Super Duplex bolts offer slightly higher strength at 125ksi UTS and 82ksi yield. In general, Duplex fasteners have significantly better toughness and ductility than ferritic grades of steel, but not the levels of austenitic grades. Usage of both Duplex and Super Duplex stainless steel should be limited to temperatures below 570°F, as extended exposure to elevated temperatures can embrittle this material.Key properties:•  High strength and fatigue resistance•  Good toughness & ductility•  Temperature usage limit: 570°F•  Low thermal expansion

Corrosion ResistanceThough Duplex steel screws are not ideal for harsh chemical environments, they do offer better corrosion resistance than 300 series stainless steel and are ideal for saltwater and chloride applications. Duplex bolts offer resistance to:•  Saltwater: salt air, brackish water and marine environments.•  Localized chloride corrosion: pitting and crevice corrosion as well as stress corrosion cracking.•  Sulfide stress corrosion resistance•  Oxidation

Duplex Fastener Styles

Common Duplex Bolt Grades

Duplex Alloy 2205 (1.4462)Duplex 2205, UNS S32205, is a stainless steel material, whose “Duplex” name is derived from the mixed microstructure which contains roughly equal portions of ferrite and austenite. This grade is the most popular variety and this two-phase material is a significant upgrade from 316 stainless steel in terms of both yield strength and corrosion resistance. Click here for more in-depth information on Duplex 2205.

DUPLEX 2205 SPECIFICATIONS: ASME SA 182, ASME SA 240, ASME SA 479, ASME SA 789, ASME SA 789 Section IV Code Case 2603, ASTM A 240, ASTM A 276 Condition A, ASTM A 276 Condition S, ASTM A 479, ASTM A 790, NACE MR0175/ISO 15156, NORSOK MDS D45 Grade F51, UNS S31803, UNS S32205, W. NR./EN 1.4462, Werkstoff 1.4462 Duplex

Super Duplex Alloy 2507 (1.4410)Super Duplex 2507, UNS S32750, is a two-phase stainless steel and is particularly well suited for use in environments such as warm chlorinated seawater and acidic, chloride containing media. It has similiar properties to Duplex 2205 but is more corrosion resistant and performs well in moderately corrosive environments. Click here for more in-depth information on Super Duplex 2507.

SUPER DUPLEX 2507 SPECIFICATIONS:  EN 10216-5, ASTM A789; A790, ASTM A182 ASTM A182, ASTM A815, ASTM A240, EN 10088-2, ASTM A479, EN 10088-3 EN 10088, ISO 15156-3, NACE MR0175, Werkstoff 1.4410 S.Duplex

TYPE  Duplex  Fasteners

Duplex  Bolts : Duplex  Hex Head Bolts, Duplex  Mushroom Head Square Neck Bolts, Duplex  T-Head Bolts, Duplex  Wing Screws, Duplex  Eye Bolts, Hstelloy Lifting Eye Bolts other types of bolts as per drawing.

Duplex  Screws :Duplex  Pan Head Slotted Screws, Duplex  Hexagon Head Screws, Duplex  Cheese Head Slotted Screws, Duplex  Countersunk Head Slotted Screws, Duplex  Countersunk Raised Head Slotted Screws, Duplex  Pan Phillips Head Screws, Duplex  Countersunk Phillips Raised Head Screws, Duplex  Slotted Cheese Trim Head Machine Screws, Duplex  Socket Head Allen Cap Screws, Duplex  Allen Countersunk Socket Head Cap Screws, Duplex  Socket Head Shoulder Screws, Duplex  Socket Head Cap Screw Low Head, Duplex  Hexagon Socket Set Screw With Flat Point, Duplex  Hexagon Socket Set Screws With Cone Point, Duplex  Hexagon Socket Set Screw With Dog Point, Duplex  Hexagon Socket Set Screws With Dog Point, Duplex  Hexagon Socket Set Screws With Cup Point, Duplex  Imperial Socket Cap Screws.

Duplex  Nuts : Duplex  Hexagon Nuts, Duplex  Hexagon Coupling Nuts, Duplex  Hexagon Thin Nuts, Duplex  Square Nuts, Duplex  Hexagon Castle Nuts, Duplex  Self Locking Nuts, Duplex  Hexagon Domed Cap Nuts.

Duplex  Washer :Duplex  Plain Washer,Duplex  Plain Big Od Washer, Duplex  Plain Small Od Washer, Duplex  Spring Lock Washer, Duplex  Spring Washer Heavy Duty, Duplex  Tooth Washer, Duplex  Serrated Star Washer, Duplex  Tab Washer With One Tab, Duplex  Tab Washer With Two Tab.