The test is performed using a specialized piece of equipment known as an Impact Tester. The apparatus consists of a vertical guide tube with a graduated scale and a heavy weight that drops through it.
At the bottom of the weight is a hemispherical (dome-shaped) indenter. When the weight drops, it strikes an indenter that rests on the coated panel. This creates a rapid deformation, causing the metal substrate to stretch and the coating to expand.
If your lab is accredited, you cannot use a "blog summary." Auditors require that you have the current, stamped version of the standard available for reference. Producing an unofficial printout will result in a non-conformance. astm d2794 pdf
It helps to know how this standard compares to others, as this is often clarified in the "Scope" section of the PDF.
| Standard | Key Difference | Best For | | :--- | :--- | :--- | | ASTM D2794 | Hemispherical indenter; coating on metal. | General industrial paint/powder. | | ISO 6272 | The international equivalent (similar but not identical load masses). | Global trade (Europe/Asia). | | ASTM G14 | Specific to pipeline coatings; uses a different dart shape. | Oil & gas pipe wraps. | | ASTM D5420 | (Gardner Impact) For plastic substrates, not metal. | Plastic car bumpers. | The test is performed using a specialized piece
Note: If you are exporting products to Europe, you might need to purchase ISO 6272-1:2017. However, many labs use ASTM D2794 because the equipment is interchangeable with minor adjustments.
Unlike some tests that simply give a "Pass/Fail" for a single condition, ASTM D2794 is usually used to find a breaking point. Unlike some tests that simply give a "Pass/Fail"
The results are reported in inch-pounds (in-lb) or Joules. A common result might look like: "Passes 160 in-lb Direct Impact."
There are specific formulas for converting metric (kg-cm) to imperial (in-lbf). A typo in a conversion can scrap a million-dollar production batch. The official PDF ensures you are using the precise math.