708M40 'T' / BS 970 1955 / EN19A
708M40 'T'
BS 970 1955
EN19A
General
708M40 IS A HIGH-QUALITY ALLOY STEEL SIMILAR TO 709M40, WITH A SLIGHT MOLYBDENUM VARIATION. SUPPLIED HEAT-TREATED TO ‘T’ CONDITION, IT OFFERS TENSILE STRENGTH OF 850–1000 N/MM², GOOD DUCTILITY, SHOCK RESISTANCE, AND WEAR PROPERTIES. IT PERFORMS WELL AT LOW AND ELEVATED TEMPERATURES. FOR ADDED SURFACE HARDNESS, IT CAN BE NITRIDED OR FLAME/INDUCTION HARDENED TO 50 HRC+. IDEAL FOR HIGH-TENSILE ENGINEERING APPLICATIONS.
Uses
HIGH TENSILE SHAFTS, BOLTS & NUTS, GEARS, PINIONS SPINDLES
Heat Treatment & Condition
CONDITION T
Chemical Analysis
C
·
0.36-0.44
Mn
·
0.70-1.00
Mo
·
0.15-0.25
S
·
0.05 MAX
Si
·
0.10-0.35
Cr
·
0.90-1.20
P
·
0.035 MAX
| C | Mn | Mo | S | Si | Cr | P |
|---|---|---|---|---|---|---|
| 0.36-0.44 | 0.70-1.00 | 0.15-0.25 | 0.05 MAX | 0.10-0.35 | 0.90-1.20 | 0.035 MAX |
Typical Mechanical Properties (EXAMPLE ONLY)
CONDITION S
TEN. STRENTH
777-925 MPa
YIELD STRENGHT
555 MPa
ELONG.
13%
HARDNESS
223-277 HB
CONDITION T
TEN. STRENTH
850-1000 MPa
YIELD STRENGHT
650 MPa
ELONG.
13%
HARDNESS
248-302 HB
CONDITION U
TEN. STRENTH
925-1075 MPa
YIELD STRENGHT
755 MPa
ELONG.
12%
HARDNESS
269-331 HB
| CONDITION S | TEN. STRENTH | YIELD STRENGHT | ELONG. | HARDNESS | CONDITION T | TEN. STRENTH | YIELD STRENGHT | ELONG. | HARDNESS | CONDITION U | TEN. STRENTH | YIELD STRENGHT | ELONG. | HARDNESS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 777-925 MPa | 555 MPa | 13% | 223-277 HB | 850-1000 MPa | 650 MPa | 13% | 248-302 HB | 925-1075 MPa | 755 MPa | 12% | 269-331 HB |