Numbering Systems for Alloys Ref: “Engineering Materials – Properties and Selection”, K.G. Budinski and M. K. Budinski, 7 th ed., Prentice Hall, 2002 (Chap. 8 – 16)

How can you tell the others exactly which kind of material you want?

What do these codes mean?  AISI 1020 steel  ASTM A 29 grade 1020 steel  UNS G10200  SAE 1006  6061-T6  3003-H38

What You Should Include in the Specifications of a Material?  Description: e.g. steel, hot-finished, low-carbon, bar, ASTM A29 grade B  Dimension  Chemical composition  Mechanical properties  Dimension tolerance: LWH, flatness, etc.  Finish: hot-rolled, cold rolled, patterned  Special requirements: heat treatment, texture, etc.

Ferrous Alloys

Some Specifications applicable to Steel Products and other Metals Specifications SAE-AISISociety of Automotive Engineers – American Iron and Steel Institute ASTM (UNS) American Society for Testing and Materials ( ASMEAmerican Society of Mechanical Engineers MILU.S. Department of Defense AMSAerospace Materials Specification BSBritish Standards Institution ( ENEuropean Committee for Standardization (

Classifications of Steel

The Most Widely Used System for Designating Steels SAE-AISI

Effects of Alloying Elements Typical ranges (%) Principle Effects Al<2Aids nitriding, grain refining, removes O in steel melting S, P<0.5Adds machinability, reduces weldability, ductility and toughness Cr0.3-4Increases corrosion resistance, hardenability, high-T strength; form hard wear resistant carbide

Effects of Alloying Elements Typical ranges (%) Principle Effects Ni0.3-5Austenite former, increase hardenability and toughness Cu Aid atmospheric corrosion resistance Mn0.3-2Austenite former, increase hardenability; combine with S to reduce its adverse effects Si Removes O in steel making, increase hardenability and toughness

Effects of Alloying Elements Typical ranges (%) Principle Effects Mo Grain refinement, increases hardenability, high-T strength V Grain refinement, increases hardenability, form wear- resistant carbide B Increase hardenability Pb<0.3Aid machinability N<0.1Acts like C in strengthening

Unified Numbering System (UNS)  Developed by ASTM and SAE  Not a specification but only identify an alloy covered by other standards  The 5 digits closely related to the original identification system. E.g. AISI 1020 = G10200  Adopted by the Copper Development Association as official identification system for Cu alloys

Most Frequently Used Carbon and Alloy Steels in the US  SAE 1010: formed sheet-metal parts  SAE 1020: general machine applications  SAE 1040: flame- or induction- hardened parts  ASTM A36: structural steel  SAE 4140: high-strength machine parts  SAE 4340: high-strength machine parts  SAE 8620: carburized wear parts

Yield Strengths Ranges of Steels

Tool Steel Categories

Tool Steel Types  High alloy content and thus high hardenability  Melted by electric furnace for cleanliness and alloy content control  Melted in small heats and subjected to tight quality control

Stainless Steel Family

Crucial Properties of Stainless Steels

A Repertoire of Stainless Steels TypeUses 430 S43000 For rust resistance on decorative an nonfunctional parts 416 S41600 Hardened to 30 HRC and use for jigs, fixtures and base plates 420 S42000 Harden to HRC for tools that do not require high wear resistance (e.g. injection-molding cavities, nozzles, holding blocks, etc) 440C S44004 Harden to HRC for cutting devices, punches and dies

A Repertoire of Stainless Steels TypeUses 303 S30300 For fasteners and shafts where only rust or splash and spill resistance are needed 304/LAll types of chemical immersion 316/LAll types of chemical immersion where 304 is not adequate 17-4 PH S17400 High stress fasteners, shafting, agitators and machine supports; age hardened 17-7 PH S17700 Harden to condition CH900 for chemical-resistant springs

Aluminium Alloys

Wrought Aluminium Alloys – Aluminum Association designation system Major Alloying ElementsSeries Commercially pure aluminium (99% min)1000 Copper (major alloying element)2000 Manganese3000 Silicon4000 Magnesium5000 Magnesium and silicon6000 Zinc7000 Other elements8000 Unused series9000 Second digit designates mill control on specific elements The last two digits have no significance, except… Indicate the Al content above 99%, e.g has 99.40% Al

Cast Aluminium Alloy Designations Major Alloying ElementsSeries Aluminium + silicon1-99 (old system) 99.5 min. aluminium1xx.x Copper2xx.x Silicon + copper or magnesium3xx.x Silicon4xx.x Magnesium5xx.x Unused series6xx.x Zinc7xx.x Tin8xx.x Other Element9xx.x The last digit indicates product form: 0 for a casting, 1 for ingot form

Additional Designation of the state of the Aluminium Alloy  Al alloys can be precipitation hardened and work-hardened to different extents. xxxx-FAs fabricated, no special control xxxx-WSolution heat-treated (used only on alloys that naturally age harden) xxxx-OAnnealed (Wrought alloys only) xxxx-HStrain hardened (cold worked to increase strength), wrought alloys only xxxx-TThermally treated to produce effects other than F, O, or H

Types of Strain Hardening and thermal treatment xxxx-H1Strain hardened only xxxx-H2Strain hardened and partially annealed xxxx-H2Strain hardened and stabilized by low-temperature thermal treatment xxxx-H4Strain hardened and lacquered or painted

Degree of Strain Hardening  The second digit indicate the degree of strain hardening  1 indicates smallest amount of cold-work and 8 indicates maximum of cold work xxxx-H_2Quarter-hard xxxx-H_4Half-hard xxxx-H_6Three-quarters hard xxxx-H_8Full-hard

Temper Designations xxxx-T1Cooled from a hot working temperature and naturally aged xxxx-T2Cooled from an elevated temperature, cold worked, and naturalled aged (means annealed for cast products) xxxx-T3Furnace solution heat treated, quenched and cold worked xxxx-T4Furnace solution heat treated, quenched, and naturally aged xxxx-T5Quenched from a hot-work temperature and furnace aged

Temper Designations xxxx-T6Furnace solution heat treated quenched and furnace aged xxxx-T7Furnace solution heat treated and stabilized xxxx-T8Furnace solution heat treated, quenched, cold worked, and furnace aged xxxx-T9Furnace solution heat treated, quenched, furnace aged and cold-worked xxxx-T10Quenched from an elevated temperature shaping process, cold worked, and furnace aged Other variations can be denoted by adding more digits after these designations

Examples  3003-H38: 3003 alloy cold finished to full hard temper and stress relieved by a low temperature treatment  6061-T6: 6061 alloy, solution heat treated and furnace aged hardened.

Most commonly used Aluminium alloys  Wrought alloys  1100 (pure Al)  2024*  3003  5052  6061*  6063*  7075*  Sand Cast  355.0*  Die Cast  *: can be age hardened Blue shaded: mainly for aerospace applications

More to come…  Steels and Al alloys are the most widely used alloys  Other important classes are Cu alloys, Mg alloys, Ni alloys and Ti alloys, etc.  ASM Metals Handbook or ASTM yearbooks are always good places to start when looking for the alloys information