ASTM D1004 Tear Resistance of Film
ASTM D1004 measures the force needed to start a tear in plastic film or sheeting. A specimen cut at a 90-degree angle with a small radius at the apex concentrates stress there, and the peak force recorded as the tear initiates is the result. MatX Lab tests packaging films, geomembranes, medical films, and flexible sheeting per ASTM D1004.
What Is ASTM D1004?
ASTM D1004 is the standard test method for tear resistance of plastic film and sheeting, sometimes called the Graves tear test. The specimen has an angular cut with a defined radius at its apex, and a tensile machine pulls the two legs apart.
The method captures tear initiation. Force rises until the material yields at the apex and a tear begins. The peak of that curve is the reported value.
Propagation is a different property measured by a different test. Where you need the force to continue a tear that already exists, ASTM D1922 by the Elmendorf pendulum method covers it, and the two results describe genuinely different behaviors of the same film.
ASTM D1004 Scope and Applications
The method applies to plastic film and sheeting up to 1 mm thick. Above that, sheet and plate behave differently, and other methods apply.
Applications:
- Packaging film specification. Setting and verifying a minimum tear initiation force for a converted film.
- Formulation development. Comparing resin grades, additive packages, and layer structures on the same converting line.
- Orientation assessment. Testing machine and transverse directions, since oriented films frequently differ by a factor of several between the two.
Puncture and multiaxial impact behavior on the same films route to ASTM D3763 and ASTM D3420—tensile properties of thin sheet run under ASTM D882. MatX Lab reports measured values and does not certify products or act as a standards body.
ASTM D1004 Test Procedure
Cutting the specimen is where this test succeeds or fails. The apex radius controls stress concentration, and a worn die can quietly drift results over months.
| Step | What happens |
| Conditioning | Specimens are conditioned at standard laboratory temperature and humidity. This is important for polyamide and other hygroscopic films. |
| Die inspection | Check the cutting die for edge condition and apex radius before cutting a batch. Die wear can cause a consistent shift in the results. |
| Specimen cutting | Die-cut specimens with a sharp apex and no nicks. Discard specimens with a damaged apex rather than test them. |
| Direction marking | Machine and transverse directions are marked on every specimen, because the two rarely give the same answer. |
| Thickness measurement | Measure thickness near the apex on each specimen without compressing the film. |
| Gripping | Clamp the legs in the tensile machine with the apex centered and unstressed at zero load. |
| Testing | Advance the crosshead at 51 mm/min, and record force through tear initiation. |
| Evaluation | Report maximum force per specimen, normalized by thickness where your specification calls for it. |
Limitations: The method measures tear initiation, not tear propagation. A film may resist the start of a tear but still allow it to spread once it begins. Results are also strongly affected by film thickness, so comparing films with different gauges without normalizing the results does not give a fair comparison of the materials. Machine and transverse direction values can differ by several times on oriented film, which means a single number without a stated direction is close to useless. Die condition drifts, and a die that has cut thousands of specimens can give different results than a new one on the same material. Thin, highly extensible films can stretch quite a lot before they tear. If the peak force is mainly due to drawing rather than the tear itself, the result needs some interpretation rather than being reported on its own. Specimen handling also matters because a crease in the apex area can determine where failure occurs.
ASTM D1004 Specimen Requirements and Test Conditions
| Parameter | Typical requirement |
| Material thickness | Up to 1 mm |
| Specimen geometry | 90-degree angular specimen with the standard apex radius, die-cut |
| Directions tested | Machine and transverse, reported separately |
| Replicates | Five per direction minimum |
| Crosshead speed | 51 mm/min |
| Conditioning | Standard laboratory atmosphere, duration recorded |
| Material required | Enough sheet to cut the specimen count in both directions plus spares |
Send film flat rather than tightly rolled. Creases and roll-set curl both affect how a specimen sits in the grips, and a crease that crosses the apex region decides the result before the test starts.
Mark the machine direction on the material. If it arrives unmarked, we will ask, and guessing the orientation makes the entire dataset ambiguous.
ASTM D1004 Test Results and Reporting
Your report gives the peak tear force (newtons) for each specimen, grouped by direction, with the mean and standard deviation for each group.
Thickness is recorded for each specimen. Where needed, we also report force per unit thickness so films with different gauges can be compared. The report also includes conditioning, crosshead speed, and die identification.
If a specimen draws a lot before tearing, or the tear runs outside the intended area, we describe this in the results rather than leaving the value unexplained. These results can sometimes give useful information about the film, even when the specimen does not fail as expected.
ASTM D1004 FAQs
What is the difference between D1004 and Elmendorf tear?
D1004 measures the force to start a tear on a tensile machine. ASTM D1922 measures the energy required to propagate an existing tear using a pendulum. Films can rank differently under the two, and specifications name one or the other for that reason.
How many specimens do I need per direction?
Five specimens is the minimum. If the film has visible gauge variation or a high filler loading, ten specimens are better. More variation in the material usually means more scatter, and five specimens may not be enough to show where that variation comes from.