Professional DIN 55656 scratch hardness tester - Applications:

1. DIN / ISO test methods (DIN EN ISO 22557:2021)

DIN EN ISO 22557 is the authoritative international standard for scratch tests with a spring-loaded hardness tester. It was specifically developed for coatings, varnishes, paints, plastics, decorative surfaces and components in automotive interiors.

Purpose of the testing procedure

The test assesses the resistance of a coating to locally limited mechanical loads, including:

• Surface scratches

• Metal markers

• Traces of writing

• Stresses similar to a fingernail

This makes the process ideally suited for quality control of high-quality decorative and functional surfaces.

Test principle

A spring-loaded scratch hardness tester (like the NIP-DINHP) is guided across the surface with a defined force. The type of pen (stylus) and the applied force determine the intensity of the scratch mark.

ISO 22557 defines two testing methods:

• Method A: Carbide ball stylus

• Method B: Disc stylus

The testing force is between 0.5 N and 20 N Adjustable, allowing for precise evaluation of different coating systems.

Overview of the process

1. Condition test specimens according to ISO environmental conditions.

2. Select the stylus type (ball or disc) according to the coating type.

3. Adjust the spring force on the NIP-DINHP.

4. Move the stylus across the surface at a constant speed.

5. Inspect the scratch mark under defined lighting conditions (ISO 13076).

6. Determine:

   • first visible continuous scratch mark

   • first perceptible scratch mark

   • Cracking or perforation of the coating

Technical Interpretation

The DIN/ISO method is ideally suited for:

• Comparison of coating systems

• Scratch sensitivity assessment

• Validation of surface modifications

• Quality control in automotive interiors

• Testing the durability of decorative surfaces

It supports both Good/Bad ratings as well as progressive strength tests.

2. ASTM Scratch Hardness Test Method (ASTM G171-24)

ASTM G171 is the American standard for scratch resistance tests with a diamond stylus. It is frequently used for metals, alloys and certain polymers.

Purpose of the testing procedure

ASTM G171 assesses the resistance of a material to permanent plastic deformation, which are caused by a single point indenter is created by moving tangentially across the surface.

Particularly relevant for:

• Abrasion resistance

• Analysis of surface damage

• Two-body wear mechanisms

Test principle

A diamond stylus is pressed onto the surface with a defined normal force and with low feed rate moved to minimize frictional heat.

In contrast to static hardness tests, scratch hardness describes the permanent deformation after removal of the stylus, measured across the Remaining scratch width.

Overview of the process

1. Prepare the test specimen to avoid breakage or delamination.

2. Apply a defined normal force to the diamond stylus.

3. Move the stylus across the surface at a low speed.

4. Measure the remaining scratch width.

5. Calculate scratch hardness value.

Technical Interpretation

ASTM G171 is ideally suited for:

• Metals and alloys

• hard functional layers

• comparative abrasion studies

• Research and materials development

It delivers a quantitative hardness value based on the geometry of the scratch mark.

3. Application of these standards in NIP-DINHP

DIN / ISO mode (primary mode)

The NIP-DINHP is specifically designed for the requirements of DIN EN ISO 22557 constructed:

• adjustable spring-loaded test force

• interchangeable ball and disc stylus heads

• controlled scratching path

• Stable ergonomics for reproducible results

This makes it ideal for coatings, plastics, decorative surfaces and components in automotive interiors.

ASTM Mode (Comparison/Research Mode)

Although ASTM G171 uses a diamond stylus, the NIP-DINHP can be used for comparative scratch resistance ratings can be used, provided a compatible stylus is used.

It is not a complete ASTM G171 device, but it does support:

• controlled scratch force

• controlled scratching path

• Inspection of the remaining scratch mark

This allows engineers Pre-tests or Comparative studies conduct procedures that are based on ASTM principles.

The Professional DIN scratch hardness test pen NIP-DINHP is a precision instrument for assessing scratch resistance according to DIN EN ISO 22557, the leading international standard for coatings and decorative surfaces. With adjustable test loads of 0.5 N to 20 N, With its interchangeable stylus types and stable spring mechanism, it enables reproducible scratch tests of laboratory quality for paints, coatings, plastics, automotive interiors and high-quality decorative surfaces.

The NIP-DINHP also supports research applications. comparative scratch resistance ratings according to the principles of ASTM G171, enabling engineers to assess the abrasion resistance and surface durability of metals, alloys and polymer materials.

This makes the NIP-DINHP an indispensable tool for:

• Material development

• Surface technology

• Quality control in automotive interiors

• Validation of decorative coatings

• industrial quality inspection

Its robust construction, precise force control and compliance with standards ensure reliable, reproducible results, which are valued in laboratories worldwide.