Simple cross-section pass (roll pass of bar and rod)
sectional shape, there is no obvious punch sub-limb part of the pass, at any point along the hole periphery made tangent do not pass through a hole section. Simple section pass box pass, square pass and round pass, oval pass, diamond-shaped hole pattern and hexagonal pass. They have the same structure, namely the roll gap s, rounded R, pass outside Rounded r World Pipe network informedWorld Steel Pipe , pass the sidewall slope of φ, the roll ring components in the pass.