Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
P
S
0.50-0.60
0.60-0.90
<=0.030 (flat rolled), <=0.040 (long products)
<=0.035 (flat rolled), <=0.050 (long products)
More data from SAE J403:2014
From the standard
Other composition limitsfrom the table and its notes
UNS number
G10550
Product scope
semifinished products for forging, hot rolled and cold finished bars, wire rods, plates, strip, sheets, welded tubing and seamless tubing
Flat rolled products
structural shapes, plates, strip, sheets and welded tubing
Long products
semifinished products for forging, hot rolled and cold finished bars, wire rods and seamless tubing
Residual limits, Option A
Cu 0.20, Ni 0.20, Cr 0.15, Mo 0.06 max
Residual limits, Option B (default)
Cu 0.35, Ni 0.25, Cr 0.20, Mo 0.06 max
Residual limits, Option C
Cu 0.40, Ni 0.40, Cr 0.30, Mo 0.12 max
Residual limits, Option D
No limits, values reported
Silicon, when required, is commonly specified as 0.10% max or a range such as 0.15 to 0.35%. Lead (0.15 to 0.35%, letter L) and boron (0.0005 to 0.003%, letter B) versions of the standard grades are identified by a letter between the second and third digits. Residual elements are agreed between purchaser and supplier; unless otherwise specified Option B applies. Option A applies to flat rolled products up to 1060.
Source: SAE J403:2014, Table 1, nonresulfurized carbon steels and its notes