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

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

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

4. 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.

5. Ferrous Alloys

6. Some Specifications applicable to Steel Products and other Metals
SAE-AISI
Society of Automotive Engineers – American Iron and Steel Institute
ASTM
(UNS)
American Society for Testing and Materials (
ASME
American Society of Mechanical Engineers
MIL
U.S. Department of Defense
AMS
Aerospace Materials Specification BS
British Standards Institution ( EN
European Committee for Standardization (

7. Classifications of Steel

8. The Most Widely Used System for Designating Steels SAE-AISI

9. Effects of Alloying Elements
Typical ranges (%)
Principle Effects Al
<2
Aids nitriding, grain refining, removes O in steel melting
S, P
<0.5
Adds machinability, reduces weldability, ductility and toughness Cr
0.3-4
Increases corrosion resistance, hardenability, high-T strength; form hard wear resistant carbide

10. Effects of Alloying Elements
Typical ranges (%)
Principle Effects Ni
0.3-5
Austenite former, increase hardenability and toughness Cu
Aid atmospheric corrosion resistance Mn
0.3-2
Austenite former, increase hardenability; combine with S to reduce its adverse effects Si
Removes O in steel making, increase hardenability and toughness

11. 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
<0.3
Aid machinability N
<0.1
Acts like C in strengthening

12. 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

13. 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

14. Yield Strengths Ranges of Steels

15. Tool Steel Categories

16. 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

17. Stainless Steel Family

18. Crucial Properties of Stainless Steels

19. A Repertoire of Stainless Steels
Type
Uses
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

20. A Repertoire of Stainless Steels
Type
Uses
303
S30300
For fasteners and shafts where only rust or splash and spill resistance are needed
304/L
All types of chemical immersion
316/L
All 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

21. Aluminium Alloys

22. Wrought Aluminium Alloys – Aluminum Association designation system
Indicate the Al content above 99%, e.g has 99.40% Al
Major Alloying Elements
Series
Commercially pure aluminium (99% min)
1000
Copper (major alloying element)
2000
Manganese
3000
Silicon
4000
Magnesium
5000
Magnesium and silicon
6000
Zinc
7000
Other elements
8000
Unused series
9000
Second digit designates mill control on specific elements
The last two digits have no significance, except…

23. Cast Aluminium Alloy Designations
Major Alloying Elements
Series
Aluminium + silicon
1-99 (old system)
99.5 min. aluminium
1xx.x
Copper
2xx.x
Silicon + copper or magnesium
3xx.x
Silicon
4xx.x
Magnesium
5xx.x
Unused series
6xx.x
Zinc
7xx.x
Tin
8xx.x
Other Element
9xx.x
The last digit indicates product form: 0 for a casting, 1 for ingot form

24. Additional Designation of the state of the Aluminium Alloy
Al alloys can be precipitation hardened and work-hardened to different extents.
xxxx-F
As fabricated, no special control
xxxx-W
Solution heat-treated (used only on alloys that naturally age harden)
xxxx-O
Annealed (Wrought alloys only)
xxxx-H
Strain hardened (cold worked to increase strength), wrought alloys only
xxxx-T
Thermally treated to produce effects other than F, O, or H

25. Types of Strain Hardening and thermal treatment
xxxx-H1
Strain hardened only
xxxx-H2
Strain hardened and partially annealed
Strain hardened and stabilized by low-temperature thermal treatment
xxxx-H4
Strain hardened and lacquered or painted

26. 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_2
Quarter-hard
xxxx-H_4
Half-hard
xxxx-H_6
Three-quarters hard
xxxx-H_8
Full-hard

27. Temper Designations xxxx-T1
Cooled from a hot working temperature and naturally aged
xxxx-T2
Cooled from an elevated temperature, cold worked, and naturalled aged (means annealed for cast products)
xxxx-T3
Furnace solution heat treated, quenched and cold worked
xxxx-T4
Furnace solution heat treated, quenched, and naturally aged
xxxx-T5
Quenched from a hot-work temperature and furnace aged

28. Temper Designations xxxx-T6
Furnace solution heat treated quenched and furnace aged
xxxx-T7
Furnace solution heat treated and stabilized
xxxx-T8
Furnace solution heat treated, quenched, cold worked, and furnace aged
xxxx-T9
Furnace solution heat treated, quenched, furnace aged and cold-worked
xxxx-T10
Quenched from an elevated temperature shaping process, cold worked, and furnace aged
Other variations can be denoted by adding more digits after these designations

29. 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.

30. Most commonly used Aluminium alloys
Wrought alloys
1100 (pure Al)
2024*
3003
5052
6061*
6063*
7075*
Sand Cast
355.0*
Die Cast
380.0
*: can be age hardened
Blue shaded: mainly for aerospace applications

31. 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