A process for producing a common rail comprising a common-rail main body and a holder therefor, the main body and the holder containing, as chemical components, 0.01-0.3 mass% carbon, 0.01-0.5 mass% silicon, 0.01-3.0 mass% manganese, 0.0003-0.01 mass% boron, 0.001-0.01 mass% nitrogen, 0.01-0.5 mass%, excluding 0.01 mass%, aluminum, and 0.01-0.05 mass% titanium, having a phosphorus content reducedto 0.03 mass% or lower, a sulfur content reduced to 0.01 mass% or lower, an oxygen content reduced to 0.01 mass% or lower, and a total content of arsenic, tin, antimony, lead, and zinc reduced to 0.015 mass% or lower, with the remainder being iron and incidental impurities, and having a TLB value of 0.001% or higher. The process comprises an insert-metal insertion step, a liquid-phase diffusion bonding step, a laser peening step, and a surface-layer removal step.