




MODERNER PPH-750 Pencil Hardness Tester is a scratch pencil Hardness Tester, which is used to test the hardness of paint film. PPH-750 Pencil Hardness Tester has a level on the surface to ensure that the trolley is in a horizontal state, and it uses a blue metal shell with high hardness, good wear resistance, and is not easy to wear. The pencil lead pressure of PPH-750 Pencil Hardness Tester is 750G.
PPH-750 Pencil Hardness Tester is designed and manufactured with reference to the national standard GB/T6739-2006 "Determination of Paint Film Hardness by Pencil Method for Paints and Varnishes", which provides a fast and economical method to measure the scratch resistance of paint film surface (and other corresponding defects).
Three points are used to contact the surface to be tested (two points are rollers, and one point is the pencil lead). The angle between the pencil and the surface to be tested is 45°. When the horizontal bubble is horizontal, the pressure on the pencil lead is 750±10 grams. The hardness of the paint film is determined by drawing a pencil of known hardness scale across the paint film.

1. Prepare the substrate according to the provisions of GB/T9271 "Standard Test Panels for Paints and Varnishes".
2. Sharpen the pencil until the lead core is exposed by 5-6 mm (keep the lead cylindrical shape), and keep the pencil perpendicular to the sandpaper to grind the end face of the lead lead until the end face becomes a complete circle without broken or notched edges. Pencils are sharpened in this way before each use.
3. Unless otherwise agreed, measure at 23±2°C and 50±5% humidity.
4. Install the pencil according to the attached drawing, and push it at least 7mm at a speed of 0.5~1mm/s. The pencil hardness of the paint film is indicated by the marked hardness of the hardest pencil that does not cause scratches of 3mm or more on the paint film.
5. Measure twice in parallel. If the results of the second measurement are inconsistent (the difference exceeds 1 pencil hardness unit), the test should be repeated.
Each instrument is equipped with: 13 advanced drawing pencils (6H~6B).
Maintenance of PPH-750 Pencil Hardness Tester
1. The PPH-I 750 Pencil Hardness Tester strives to rotate flexibly when used. After a period of use, oil must be injected into the rotating parts such as screw rods and bearings.
2. After the PPH-I 750 Pencil Hardness Tester has been used for a period of time, the set screws and nuts must be tightened to avoid loosening.
The main technical differences before and after the revision of the GB/T 6739 standard
| Difference content | The current standard GB/T 6739-1996 | Revised standard |
| Bidding situation | Equivalent to JIS K 5400 -9 -8.4 | Equivalent to ISO 15184:1998 |
| Substrate can be used | Steel plate, tinplate version | Substrates that meet the requirements of GB/T 9271 can be used, such as steel plates, tinplate plates, aluminum plates, wood plates, etc. |
| Applied load | Instrument method: (1000 ± 50) g | Instrument method: (750 ± 50) g |
| pencil hardness number | 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B | 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B, 7B, 8B, 9B |
| pencil lead exposed length | 3mm | 5~6mm |
| Tool for wiping the surface of the paint film after the test | Advanced Drawing Eraser | Soft cloth, absorbent cotton, or drawing eraser |