Steel pistons have been used successfully in commercial vehicle for several years now. They became necessary because manufacturers wanted to fulfill the various stages of emissions legislation with measures inside the engine for as long as possible while power density levels increased. Consequently, peak cylinder pressures of over 220 bar can sometimes act on the piston, making high-strength steel designs inevitable. MAHLE has developed four different steel piston concepts for these applications to date, the newest member of the family being the friction-welded MonoWeld® piston. In the future, new manufacturing methods such as the beam-based welding process recently developed by MAHLE will open up new degrees of freedom in manufacturing, especially in order to further reduce the compression height of pistons.