BS 970 steels.. Basic Notes on steels..... Sample specifications...... BS 970 numbering system explained...... M odern equivalents to BS 970 1955;EN numbers...... Important Notes: 1) BS 970 has been generally superseded by European based standards Notes on European Standards 2) All information on this page has been interpreted from the relevent Standard, Books eg Newnes M ech. Eng Pocket Book, Kempe's, Other Web Sites, and Leaflets. This information is of a general nature for initial guidance. Selection of materials for use must be by communication with the suppliers and by reference to the appropriate codes - The best standards to use are the European EN based standards Basic S teel S election Based on BS 970
Typical selection of steels and useful notes STEEL
Notes
Carbon Steel BS 970 230M 07 (EN1A)
A low carbon, free cutting, mild steel suitable for machining using automatic and CNC machines. Available as rolled or normalised in round, flat or hexagon form
BS 970 070M 20 (EN3A)
A mild steel used for general purposes. Suitable for lightly stressed fasteners ,shafts etc. Can be easily machined and welded. Available hot rolled, normalised, cold drawn or turned. Supplied in Black round or square , bright round square, flat and hexagon.
BS 970 080M 30 (EN5/EN6)
A medium strength steel. Used to make, shafts, racks, pinions, studs, bolts, nuts, rollers, etc. Supplied as square bar, or round bar or flat.
BS 970 080M 40 (EN8)
A medium strength steel. Suitable for stressed pins, shafts studs, keys etc. Available as rolled or normalised. Supplied as square bar, or round bar or flat.
BS 970 070M 55 (EN9)
A hard wearing medium carbon steel which can be hardened. Available as hot rolled, normalised, Cold drawn or turned. Sections available black round, black square, bright round and black flat.
BS 970 080M 15 (EN32)
A case hardening mild steel suitable for general engineering applications. When case hardened results in a hard surface with a tough core. Used for making gears cams and rollers etc. Supplied as black round bar and sections
Alloy Steel BS 970 605M 36
A manganese molydenum steel with good ductily and mechanical strength. Available in heat treated condition e.g (R,S,T).Supplied as black round or
(EN16)
square bar and bright round or square, and hexagons.
BS 970 709M 40 (EN19)
A 1% typical chromium molybdenum steel with higher molybdenum. Can be induction hardened. Used for gears, and high strength shafts etc. Suitable for higher strength applications when resistance to shock is required. Available annealed. Supplied as black round or square bar and bright round or square, and hexagons.
BS 970 817M 40 (EN24)
A nickel chromium molybdenum steel with high strength and toughness. Used for gears axles and high strength studs. Supplied as rolled, annealed and hardened and tempered. Supplied as black round or square bar and bright round or square, and hexagons
BS 970 655M 13 (EN36)
A high quality nickel chromium case hardening steel. Can be hardened to provide hard surface with a strong tough core. Used for high duty gears and shafts. Supplied in as-rolled condition in black square and round bar and bright round.
BS 970 722M 24 (EN40B)
A 3% chromium molybdenum nitriding steel. Provide good tough core strength with a hard nitrided surface for wear resistance. Supplied in as-rolled, annealed and hardened and tempered condition in black square and round bar.
Stainless Steel BS970 416S21 (EN56)
M artensitic (M agnetic), can be hardened and tempered to give improved tensile strength. FM ** grade. Typical applications include cutlery, surgical instruments, fasteners, valves, spindles and shafts.
BS 970 431S29 (EN57)
M artensitic (M agnetic). Supplied heat treated with a high tensile strength. Typical applications include cutlery, surgical instruments, fasteners, valves, spindles and shafts.
BS 970 Ferritic. Low Strength but good ductility. Used food processing and catering 430S15 equipment and automotive trim,car exhaust systems etc. typ (EN60)
BS 970 Grade 304S15 (EN58-)
Austenitic (Non-M agnetic)Cannot be heat treated but work hardens. Readily formed and welded,used mainly in domestic, dairy and decorative appliances general purpose grade for corrosion resistant applications. This grade is the most widely used of all stainless steels. Its chemical composition,provide the best all-round performance S.S. at relatively low cost. It has excellent low temperature properties. Lower Carbon grades (S15 and less) have improved weldability.
BS 970 Grade 316S16 (EN58J)
Austenitic (Non-M agnetic)Cannot be heat treated but work hardens. It offers high resistance to corrosion. Generally machined components and pipe fittings. This grade is almost as popular as the 304 grade the increased M o content makes the steel more suitable for resisting pitting and crevice then 304 Grade. Lower Carbon grades (S15 and less) have improved weldability.
BS 970 Austenitic (Non-M agnetic)Cannot be heat treated but work hardens. Grade Titanium stabilized, which offers improved welding properties. 321S12 (EN58B-C) BS 970 Grade 310S31
Austenitic (Non-M agnetic). Pocesses good resistance to scaling at high temperatures. For continuous high temperature service in the range 850 1000oC.
S ample S teels S pecifications Typical steels with general specifications notes Important Note: The values below are not comprehensive and must be used with extreme care. The strength values e.g. the proof stress and yield stress, reduce as the section increases. In the tables below the relevant sections are often thin and so the strength values are maximum values. Please refer to the relevant standards for important work..
Type Of Steel
BS Spec Composition % BS 970 C-M n-Ni-Cr-M o
Condition
Yield Stress x 106 Pa
Tensile Elongation Stress M Pa %
Low Carbon Steel 230M 07 0,15C% 1,1%M n
Hot rolled
215
360
21
Low Carbon Steel 230M 07 0,15C% 1,1%M n
HR -> CD (thin)
340
480
6
Low Carbon Steel 070M 20 0,2C% 0,7%M n
Normalised
215
430
21
Low Carbon Steel 070M 20 0,2C% 0,7%M n
HR->CD (thin)
440
560
10
Constructural Steel
080M 40 0,4%C 0,8%M n
Normalised
280
550
16
Constructural Steel
080M 40 0,4%C 0,8%M n
HR -> CD (thin)
530
660
7
Low M anganese
150M 28 0,28%C 1,5%M n
Heat Treat(P)
355
587
20
Heat Treat(R)
525
700 min
17
1000
1130
19
755
927
23
Nickel M anganese 503M 40 0,4%C -0,9%M n 1,0%Cr M anganese M olybdenum
608M 38 0,38%C 1,5%M n 0,5%M o Heat Treat
Nickel Chromium 633M 31
0,31%C 0,60%M n 3,0%Ni Heat 1,0%Cr Treat(U)
NickelChrom-M o
817M 40
0,4%C 0,55%M n 1,2%Cr Heat Treat 0,3%M o (W)
940
1075
11
NickelChrom-M o
835M 30
0,3%C 0,55%M n 4,25%Ni Hard'n 1,25%Cr 0,3%M o +Temp
1470
1700
14
M ang-Ni-Chr-M o 945M 38
0,38%C 1,4%M n 0,75%Ni Heat Treat 0,5%Cr 0,20%M o (V)
850
1040
2
Steel Ferritic
403S17
0,08%C 1,0%M n 13%Cr 0,5%Ni
Softened
280
420
20
Stainless M artensitic
420S45 0,3%C 0,5%M n 13,0%Cr
Heat Treat (R)
525
700
15
18/8 Stainless Austenitic
302S25
0,12%C 0,8%M n 8,5%Ni Softened 18,0%Cr
278
618
50
18/8 Stainless Austenitic
302S25
0,12%C 0,8%M N 8,5%Ni Cold work 18,0%Cr
803
896
30
278
649
45
Cold Worked 402
803
30
0,05%C 0,8%M n 8,5%Ni 18/8 St. (No Weld Softened 321S20 18,0%Cr 1,6Ti Decay) 0,05C 0,8%M n 8,5%Ni 18/8 St. (No Weld 321S20 18,0%Cr 1,6Ti Decay)
BS 970 Numbering system explained The BS970 code number is constructed as follows; a) The first three symbols are a number code indicating the type of steel: 000 to 199 Carbon and carbon-manganese steels. The number represents the manganese content x 100 200 to 240 Free cutting steels. The second and third number indicate the sulphur content x 100 250 Silicon M anganese valve steels 300 to 499 Stainless and heat resisting steels 500 to 999 Alloy Steels
b) The fourth symbol is a letter code . A The steel is supplied to a chemical compostion determine by analysis of the batch sample. H The steel is supplied to a hardenability specification M The steel is supplied to a M echanical Property specification.
S The steel is a stainless steel
c) The fifth and sixth symbol is a number is the actual mean carbon content x 100
In addition to the above coding a condition coding may be applied. indicating the tensile strength range after heat treatment. This is used in conjunction with a limiting section designation. (See table below) Condition Code Letter
Tensile Strength (M pa) M in
M ax
P
550
700
Q
620
770
R
700
850
S
770
930
T
850
1000
U
930
1080
V
1000
1150
W
1080
1240
X
1150
1300
Y
1240
1400
Z
1540
-
Table of BS 970: 1955 EN equivalents * Steel No Relate to European Numbering system BS EN 10027-2 - I will add numbers as I locate them BS970 1955 EN steel Equivalent
BS970 1955 EN steel Equivalent EN No BS 970 Name Note.
* Steel No
1A
230M 07
Low Carbon Free Cutting C
1.0715
1B
240M 07
Low Carbon Free Cutting C
-
3A
070M 20
'20' C
1.0402
5
080M 30
'30' C
1.1178/1.1179
5A
080A27
'30' C
5B
080A30
'30' C
1.0528
8
080M 40
'40'C
1.0503/1.0511
EN No
BS 970 Name Note.
39A
659M 15
34
665M 17
35A
665A22
1.5% Ni/M o
35
665M 23
1.5% Ni/M o
35B
665A24
1.5% Ni/M o
361
805M 17
0.5% Ni/Cr/M o
362
805M 20
0.5% Ni/Cr/M o
363
805M 25
0.5% Ni/Cr/M o
353
815M 27
1.5% Ni/Cr/M o
4.0% Ni/Cr
*Steel No
354
820M 27
1.75% Ni/Cr/M o
355
822M 17
2.0% Ni/Cr/M o
'42'C
36C
832M 13
3.0% Ni/Cr/M o 1.6657
070M 55
'50'C
635M 15
0.75% Ni/Cr
43A
080A50
'50'C
1.1209/1.0535 351 352 1,1206
637M 17
1% Ni/Cr
43B
080A47
'47'C
36A
655M 13
3.25% Ni/Cr
43C
080A52
'52'C
39A
659M 15
4.0% Ni/Cr
43D
080A62
'62'C
34
665M 17
1.75% Ni/M o
43E
080A67
'67'C
35
665M 23
1.75% Ni/M o
1A
220M 07
Low Carbon FC**
361
805M 17
0.5% Ni/Cr/M o
362
805M 20
0.5% Ni/Cr/M o 1.6522'3
1B
240M 07
Low Carbon FC**
363
805M 25
0.5% Ni/Cr/M o
353
815M 17
1.5% Ni/Cr/M o
8M
212M 36
'36' C FC**
15AM 216M 36
'36' C' FC**
354
820M 17
1.75% Ni/Cr/M o
8BM
212A37
'37' C FC**
355
822M 17
2.0% Ni/Cr/M o
8DM 212M 44
'42' C FC**
36C
832M 13
3.5% Ni/Cr/M o 1.6657
8M
212M 44
'44' C FC**
39B
835M 15
4.0% Ni/Cr/M o
12
503M 40
1% Ni
43
080A22
'52'Carbon
12B
503A37
1% Ni
43E
080A67
'67'Carbon
12C
503A42
1% Ni
42
070A72
'52'Carbon
11
526M 60
1% Cr
44
060A96
'96'Carbon
1.1274
18
530M 40
1% Cr
1.7035
18A
530A30
1% Cr
1.8401
45
250A53
1.0904
18B
530A32
1% Cr
1.7033
SilicoM anganese '53'Carbon
18C
530A36
1% Cr
45A
250A58
'58'Carbon
18D
530A40
1% Cr
45A
250A61
'61'Carbon
31
534A99
1.5% Cr
47
735A50
1.0% Cr
31
535A99
1.5% Cr
48
527A60
0.75% Cr/Va
16D
605M 30
1.5% M n/M o (Water Hardening)
16
605M 36
1.0% M n/M o
16B
605A32
1.0% M n/M o
16C
605A37
1.0% M n/M o
8A
080A35
'35'C
8B
080A37
'37'C
8C
080A40
'40'C
8D
080A42
9
1.1186
1.1221
1.0726
?1.0727
1.7035
1.8159
Stainless Steels 302S25
CrNi 18/9 C 0,12 ..Aust
58M
303S41
CrNi 18/9 S bearing FM **..Aust
58E
304S15
CrNi 18/19 C 0,06 ..Aust
58A 1.7006 1.5432
1.4828
1.4301
315S16
CrNiM o 17/10/1,5 C 0,07 ..Aust
316S16
CrNiM o 17/11/2,5 C 0,07 1.4401 ..Aust
316S17
CrNiM o 17/12/2,5 +Ti C 1.4401 0,08 ..Aust
1.7225
58B/58C 321S12
CrNi 18/9 +Ti C 1.4541 0,08 ..Aust
1.7361
58B/58C 321S20
CrNi 18/9 +Ti C 0,12 ..Aust
58M
325S21
CrNi 18/9 +Ti 1.4305 +S FM ** ..Aust
54
331S40
NiCrW 14/14/2,5..Valve
331S42
NiCrW 14/14/2,5 + M o ..Valve
16M
605A32
1.5% M n/M o(FC**)
111
640M 40
1.25% Ni/Cr
111A 640M 40
1.25% Ni/Cr
23
653M 31
3.0% Ni/Cr
19A
708M 40
1.0% Cr/M o
1.7223
19B
708A37
1.0% Cr/M o
1.7220
58J
19C
708A42
1.0% Cr/M o
19
709M 40
1.0% Cr/M o (Higher M o)
40B
722M 24
3.0% Cr/M o (Nitriding)
13
785M 19
1.5% M n/Ni/M o
110
816M 40
1.0% Ni/Cr/M o 1.6582 (Low M o)
58H
58J
24
817M 40
1.0% Ni/Cr/M o 1.6582/1.6565
25
826M 31
2.5% Ni/Cr/M o (M edium C)
54A
26
826M 40
2.5% Ni/Cr/M o 1,6746 (High C)
58F/58G 347S17
Cr/Ni 18/9/Nb/C 1.4550 0,08 ..Aus
52
401S45
Si/Cr 3/8 ..Valve
56A
410S21
13CrC0,12 M art
1.4006
56AM
416S21
13Cr C 0,12 S FM ** ..M art
1.4005
56AM
416S41
13Cr C 0,12 Se FM ** ..M art
416S29
13Cr C 0,17 S FM ** ..M art
27
830M 31
3.0% Ni/Cr/M o
30B
835M 30
4.0% Ni/Cr/M o 1.6747
897M 39
3.25% Ni/Cr/M o/Va (Nitriding)
40C
905M 31
1.5% Cr/Al/M o (Nitriding) 1.8509 (M edium C)
905M 39
1.5% Cr/Al/M o (Nitriding)(High C)
56BM
1.5% M n/Ni/Cr /Al/M o
56C
416S37
13Cr C 0,24 S bearing FM ** ..M art
100C 945A40
1.5% M n/Ni/Cr 1.6546 /Al/M o
56B
420S29
13Cr C 0,17..M art
1.4024
351
635M 15
0.75% Ni/Cr
56C
420S37
1.4021
352
637M 14
1.0% Ni/Cr
13Cr C 0,24 ..M art
36A
655M 13
3.25% Ni/Cr
1.5752
56D
420S45
1.4028
36A
655M 13
3.25% Ni/Cr
1.5752
13Cr C 0,32..M art
41A
41B
100
945M 38
60
430S15
17Cr C 0,10....Fer
1.4016
57
431S29
17Cr 2,5NI C 0,10....M art
1.4057
59
443S65
CrNiSi 20,1.5,2..Valve
Stainless Steels ...Aus = Austenitic, M art = M artensitic, Fe = Ferritic. FC** = Free Cutting.. FM ** = Free machining
Relevant S teel Links 1. 2. 3. 4. 5. 6.
British Stainless Steel Association ..Properties /Relevant Standards for Stainless Steels Plymouth College ..Notes On Steels Grade Alternatives... M ikra metal Stainless Steel Grades M aterial Cross Reference List..Coromant- Sandvik Comprehensive list of steels Australian Stainless Steel Development Agency ..Contains physical and mechanical properties Key-To-Steel ..An excellent reference site for steel classifications and properties.- registration required for full access 7. Casti M etals Black Book ..Download Document. A comprehensive reference text on european metals including Ref to latest Standards
