Lonroy BGD 506/4 铅笔硬度试验机 (7.5N±0.1N/765g)

■ Three points are touched on the tested surface (roller, pencil lead)

■ The angle between pencil and the tested surface: 45°

■ Built-in spirit bubble, convenient to check level when tester is working

■ Pressure of pencil tip: 7.5N±0.1N/765g