Hi I am trying to understand difference betwen thees two alloys, constituent composition and percentages are pretty identical

4140H 4140
C

0.37-0.44 C

0.38-0.43
Mn

0.65-1.10 Mn

0.75-1.00
Cr

0.75-1.20 Cr

0.80-1.10
Mo

0.15-0.25 Mo

0.15-0.25
P

0.035 P

0.035