Test principle
The steel shaft used to simulate children's fingers needs to be hardened. The surface Rockwell hardness should be no less than 40, the surface roughness should not be greater than 0.40 microns, and the diameter should be 9.35 mm ± 0.12 mm. A layer of simulated artificial skin tape was applied perpendicularly to a steel shaft wrapped with simulated artificial skin glue with a force of 6 N (1.35 lb). The steel shaft was constant tangent at 23 mm/sec ± 4 mm/sec. The speed is rotated for one week. Check the edge of the test to cut (cut) the simulated artificial skin adhesive paper. If cut (cut), the tested edge is defined as a potentially dangerous sharp edge.