GB/T 699:2015 40 Steel: Specifications & Listings

GB/T 699:2015 40: 40: quality carbon structural steel for hot-rolled or forged bars. Specified in GB/T 699:2015.

Forms: Round Bar Category: Carbon Steel
Grade Details
GradeGB/T 699:2015 40
Standard GB/T 699:2015
ApplicationsUsed for gears, shafts, axles, crankshafts, couplings, and machine spindles.
Most Active InWest (Maharashtra)
Equivalent / Similar Grades
Grade Standard Region Live on M-EX
SS 14 21 72 2172 SS 14 21 72 Sweden 2 listings, 0 RFQs →
UNI 7845 C45 UNI 7845:1978 Italy 2 listings, 0 RFQs →
Supply & Demand by FormSee Full Supply & Demand →
Round Bar →
Low Activity
Grade ComparisonCompare With a Specific Grade →
Grade Standard Match
GB/T 699 35Mn GB/T 699:2015 Related Material
GB/T 699 30Mn GB/T 699:2015 Related Material
IS 1570 (Part 4) 15Cr6Ni6 IS 1570 (Part 4):1988 Related Material
SAE J404 50B46 SAE J404:2009 Related Material
EN 10084 16NiCr4 EN 10084:2008 Related Material
EN 10084 16NiCrS4 EN 10084:2008 Related Material
BS 970 (Part 3) 635M15 BS 970 (Part 3):1991 Related Material
BS 970 (Part 3) 637M17 BS 970 (Part 3):1991 Related Material
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C Si Mn P S Cr Ni Cu
0.37-0.44 0.17-0.37 0.50-0.80 <=0.035 <=0.035 <=0.25 <=0.30 <=0.25
Mechanical Properties
Tensile Strength >=570 MPa
Yield Strength >=335 MPa
Elongation >=19%
Hardness <=217 HB (as delivered, not heat treated)
Condition Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state

More data from GB/T 699:2015

From the standard
Mechanical properties (normalized) for bars up to 80 mm
Tensile strength Rm, min
570 MPa
Lower yield strength ReL, min
335 MPa
Elongation after fracture A, min
19 %
Reduction of area Z, min
45 %
Longitudinal tensile properties from the sample blank; for 80 to 250 mm bars elongation may be 2 percent (absolute) and reduction of area 5 percent (absolute) lower. Yield may be replaced by Rp0.2 where there is no distinct yield.
Source: GB/T 699:2015, Table 2
Impact absorbed energy KU2 min
Impact absorbed energy KU2, min
47 J
Source: GB/T 699:2015, Table 2
Recommended heat treatment recommended heat treatment
Blank sample size
25 mm
Normalizing temperature
860 deg C
Quenching temperature
840 deg C
Tempering temperature
600 deg C
Permissible adjustment: +/-30 deg C normalizing, +/-20 deg C quenching, +/-50 deg C tempering; hold at least 30 min (1 h for 600 deg C tempering); quench in oil for 75, 80 and 85 steels, otherwise water.
Source: GB/T 699:2015, Table 2
Maximum delivery hardness 2 delivery states
Delivery stateMaximum hardness (HBW)
Not heat treated217
Annealed187
Source: GB/T 699:2015, Table 2

Popular forms for this grade:

Round Bar (2)

Active GB/T 699:2015 40 Listings on M-EX (For Sale)

+ Create a Listing for this grade
GB/T 699:2015 40 Round Bar
2.800 MT
View Listing
GB/T 699:2015 40 Round Bar
3.200 MT
View Listing

Buyer RFQs for GB/T 699:2015 40

+ Post an RFQ for this grade

No open buyer requirements for GB/T 699:2015 40 at this time.

Register for Alerts