1. SPECIFICATION OF ENGINEERING MATERIALS

2. DESIGNATION OR IDENTIFICATION OF MATERIAL CLASS BY A NUMBER, LETTER, SYMBOL, NAME OR A COMBINATION IS CALLED SPECIFICATION.
NORALLY BASED ON MECHANICAL PROPERTIES OR CHEMICAL COMPOSITION.

3. MATERIALS CLASSIFIED AND DESIGNATED AS PER FOLLOWING STANDARD
BIS- BEAURO OF INDIAN STANDARD
AISI- AMERICAN IRON AND STEEL
INSTITUTE
SAE- SOCIETY OF AUTOMOTIVE ENGINEERS
BS- BRITISH STANDARDS

4. DESIGNATION OF FOLLOWING MATERIALS ARE CONSIDERED---( AS PER IS)
CAST IRON
PLAIN C STEELS
TOOL STEELS
LOW AND MEDIUM ALLOY STEELS
(ALLOYING ELEMENTS < 10 % )
HIGH ALOY STEELS

5. DESIGNATION OF CAST IRONS FIRST SYMBOL FOR TYPE OF CAST IRON
NUMBER – INDICATES MINIMUM TENSILE STRENGTH
SYMBOLS AS
FG – GRAY CI
WM – WHITE HEART MALLEABLE CI
PM – PEARLITIC MALLEABLE CI
SG – SPHEROIDAL GRAPHITE CI
e.g.
FG150
GRAY CI TS 150 N/SQ.MM
IT IS GRAY CAST IRON WITH MIN. TS 150 N/SQ.MM OR MPa

6. WM250- WHITE HEART MALLEABLE CI WITH
MIN. TS=250 N/SQ.MM
SG150- SPHEROIDAL GRAPHITE WITH MIN. TS=150 N/SQ.MM
DESIGNATION ON THE BASIS OF MECHANICAL PROPERTIES…
DESIGNATED BY TENSILE OR YIELD STRENGTH
Fe- INDICATES STEEL
E – INDICATES YIELD STRENGTH
K- KILLED STEEL

7. IF E IS NOT SHOWN THEN TS IS CONSIDERED. e.g.
Fe 350 – STEEL WITH MIN. TS 350 N/SQ.MM
Fe E 380 – STEEL WITH MIN. YIELD STRENGTH N/SQ.MM
E- FOR YIELD STRENGTH
Fe 410 K – KILLED STEEL WITH MIN TS 410 N/SQ.MM
K- KILLED AND Fe FOR STEEL i.e. KILLED STEEL
KILLED STEEL IS DEOXYDIZED FULLY SO THAT CASTING ARE SOUND AND FREE FROM BLOW HOLES.

8. 0.4 % CARBON AND 0.8 % Mn DESIGNATION AS PER CHEMICAL COMPOSITION:
PLAIN C STEELS:
e.g.
40C8
0.4 % CARBON AND 0.8 % Mn
NUMBER AFTER C IS PERCENT OF Mn
FOR Mn MULTIPLYING FACTOR IS 10 i.e. 10/100=1/10
SO 8/10=0.8 %
NUMBER BEFORE C SHOWS % CARBON 40/100=0.4%

9. TOOL STEEL CONTAINING 0.1 % C , 0.4 % Mn
45 C 10 S 18
0.45 % C, 1.0 % Mn, 0.18 % S
PLAIN C STEELS HAVE C, P, S, Mn, Si AS INGREDIENTS
Except Mn all elements are considered 100% i.e. divide by 100, as 18/100 = 0.18 %
DESIGNATION OF TOOL STEELS:
10 T 4
TOOL STEEL CONTAINING 0.1 % C , 0.4 % Mn
T- INDICATES TOOL STEEL

10. ALLOYING ELEMENTS MULTIPLYING FACTOR Cr, Co, Ni, Mn, Si, W 4
DESIGNATION OF LOW AND MEDIUM ALLOY STEELS:
FIRST NUMBER --- INDICATES % CARBON
SECOND, FOURTH, SIXTH – INDICATES ALLOYING
ELEMENTS
THIRD, FIFTH, SEVENTH – INDICATES MULTIPLYING
FACTOR/100
ALLOYING ELEMENTS
MULTIPLYING FACTOR
Cr, Co, Ni, Mn, Si, W 4
Al, Pb, Cu, Be, V, Nb, Ti, Mo 10
P, S, N
100

11. LOW ALLOY STEEL 0.4 % C , 1 % Cr, 0.3 % Mo
DIVIDE BY MULTIPLYING FACTOR
i.e. 4/4=1 % FOR Cr,
AND 3/10=0.3 % FOR Mo
35 Mn 6 Mo 3
ALLOY STEEL WITH 0.35 % C, 1.5 % Mn, 0.3 %Mo
ALLOYING ELEMENTS
MULTIPLYING FACTOR
Cr, Co, Ni, Mn, Si, W 4
Al, Pb, Cu, Be, V, Nb, Ti, Mo 10
P, S, N
100

12. XT 75 W 18 Cr 4 V 1 DESIGNATION OF ALLOY STEEL & HIGH ALLOY TOOL STEEL
X- INDICATES HIGH ALLOY STEEL
XT – INDICATES HIGH ALLOY TOOL STEEL
MULTIPLYING FACTOR NOT USED
FOR ALLOYING ELEMENTS NUMBER GIVES % OF ELEMENTS
e.g. X 15 Cr 25 Ni 12
HIGH ALLOY STEEL 0.15 % C, 25 % Cr, 12 % Ni
XT 75 W 18 Cr 4 V 1
HIGH ALLOY TOOL STEEEL % C , 18 % W, 4 % Cr, 1 % V

13. STATE THE MEANING OF THE FOLLOWING …
TOOL STEEL HAVING 0.7 % C
Fe 470 W
STEEL WITH MIN TS 470 N/SQ.MM AND HAVING GOOD WELDABILITY
45 C 10 S 18
STEEL WITH 0.45 % C, 1.0 % Mn, % S
XT 60 W 12 Cr 4 V 1
HIGH ALLOY TOOL STEEL WITH % C, 12 % W, 4 % Cr, 1 % V

14. AISI- AMERICAN IRON STEEL INSTITUTION DESIGNATION
35C8 i.e %CARBON, 0.8 % Mn.
AISI1035 i.e. plain carbon steel containing 0.35 % carbon. (Digit 1 indicates plain c steel.)
AISI5140, AISI4140,AISI6150,AISI8640.
1st digit indicates type of steel.
2nd digit for predominant alloying element.
3rd &4th digit indicates% of carbon in hundredth.

15. e.g. 1 for plain carbon steel, 2 nickel series, 3 for nickel chromium, 31 for manganese steel. 4 for chromium steel. 41 for chromium-molybdenum steels, 51 for medium chromium, 61 Chromium-vanadium series. 92XX FOR SILICON SERIES. AISI5140 i.e. medium cr steel with 0.40%c.

16. THANKS !!!