435 Scratch Hardness Tester

Surface marks look very unsightly, especially on smooth, glossy surfaces, which are easily spoiled – fingernail marks on a matt-lacquered table top, for example, or marks left by sticks on shiny objects. Such small causes can lead to big problems.

Scratches can also be caused by metal objects: metal particles on coins, jewellery or rings. Any of these can damage a paint film.

The traditional test of a surface's resistance to this kind of damage is to try to mark it with a fingernail. With the Model 435 Hardness Tester, surface quality can be measured precisely.

The disc-shaped scratch tool, with a locking device, is made of special plastic or metal. It is mounted on a screw and loaded by a coil spring, which applies an adjustable force of 0–20 N. The instrument is placed on the test surface so that it rests on two guide wheels; the marking wheel is locked in position and pressed onto the surface at the preset spring force. Spring force is divided into 3 ranges, each with an interchangeable spring.

Spring range 1:    0–3 N  sensitivity: 0.1 N

Spring range 2:    0–10 N  sensitivity: 0.5 N

Spring range 3:    0–20 N  sensitivity: 1.0 N

Spring range 1:    0–3 N  sensitivity: 0.1 N

Spring range 2:    0–10 N  sensitivity: 0.5 N

Spring range 3:    0–20 N  sensitivity: 1.0 N

#435 Scratch Hardness Tester (Chinese).pdf