Diablo Amped Thick Metal Carbide Teeth Reciprocating saw blades are made to cut steel up to 9/16" as well as stainless steel.

Diablo Amped Carbide 9inch: homedepot.sjv.io/WjQmP
Diablo Amped Carbide 6inch: homedepot.sjv.io/nO606

We put our blades to the test using schedule 40 4" pipe (1/4" wall) as well as some 8" Cchannel with 5/16" thick steel and more than 1/2" thick webbing. Even after cutting multiple cuts through the pipe and Cchannel, we didn't have any missing carbide teeth on the blades.
These Diablo Amped recip blades for thick metal can be purchased in 4", 6", 9", and 12" lengths, as well as 1, 2, 3, and 10packs.