Why does profile scratch occur during roll forming processing?

Profile scratching is one of the most common defects in roll forming production, mainly triggered by damaged forming rollers, foreign impurities, improper equipment adjustment and irregular raw materials.

First, defective roller surface is the primary cause. Scratches, pits and burrs on roller outer circle from long-term abrasion or poor heat treatment will continuously scrape the coating and base metal of steel strip during extrusion. If forming rollers lack surface quenching treatment, they wear quickly and leave uniform linear scratches on finished profiles. Improper roller installation such as deflection and eccentric rotation also produces sharp contact points to damage material surface.

Second, iron scraps, welding slag and metal dust fall into the forming area and stick on roller surfaces. These hard impurities are pressed between rollers and steel strip, forming intermittent strip scratches. Unclean raw coils with surface rust, burrs and residual oxide skin will drop debris and scratch profiles in continuous feeding.

Third, unreasonable clearance adjustment between upper and lower rollers causes scratching. Too small roller gap squeezes material excessively and scrapes surface coating; inconsistent gap on left and right sides leads to strip partial extrusion damage. Excessive feeding speed increases friction between strip and guide baffle, resulting in edge scratches.

In addition, worn guide brackets, rough inner surface of feeding channel and offset running of steel strip make the sheet rub against fixed metal parts randomly. Regular roller polishing, raw material cleaning and periodic gap calibration can effectively reduce scratch defects.

1. GB/T 7714-2015

[1] Zhao X. Cause Analysis and Preventive Measures of Profile Scratch in Roll Forming Production[J]. Mechanical Equipment & Processing,2025,36(10):49-56.

2. APA 7th

Zhao, X. (2025). Cause analysis and preventive measures of profile scratch in roll forming production. Mechanical Equipment & Processing, 36(10), 49–56.

3. MLA 9th

Zhao, Xin. "Cause Analysis and Preventive Measures of Profile Scratch in Roll Forming Production." Mechanical Equipment & Processing, vol.36, no.10, 2025, pp.49-56,