The definition of shaw hardness test
Using theISO 7619-1orASTM D2240Standardized test procedures, according to shaw method to determine the hardness of rubber elastic polymers and elastomers.Shaw hardness test is usually not used for metal.
inShaw hardness test, the use of hardened steel spring loaded type head make impression material/sample, thus measuring indentation depth.Is the indentation depthShaw hardnessA method of measuring in 0 shaw hardness indentation depth (2.5 mm) to 100 shaw hardness (0 mm indentation depth) on the scale of measurement.According to different pressure head form and spring characteristics, set up different shaw hardness scale.One of the most famous scale is A and shaw shaw hardness hardness D.Other ruler, such as: shaw hardness B, C, 0, 0, 000 and D0, for some special applications.
Shaw hardness scale and application example:
- A: shaw hardness of soft rubber, elastomers and natural rubber
- D: shaw rigidity elastomer, plastic and rigid thermoplastic plastics
- Shaw hardness 0: soft elastomer and textiles
- Shaw hardness 00: porous rubber, sponge rubber and foam rubber
- B: shaw hardness hardness more than shaw hardness A hard elastomer
- Shaw hardness C: medium hard elastomer
VLRH (IRHD super soft)
Shaw hardness 00
Shaw hardness A/B
Shaw hardness A/B
Shaw hardness D/C/do
Microscopic shaw hardness
Up to the standard of ISO 7619-1 and ASTM D2240 shaw hardness test
Shaw hardness testIs a kind of static test method, the characteristics are as follows:
- Is one of the standardized method (ISO 7619-1 and ASTM D2240Standard).
- The method for determination of the hardness of macro scope, 3.924-50 N test force.
- Is a kind of depth measurement.This means that in order to determine hardness values of the specimens, the measurement is real indentation depth instead of pressure head produced by the permanent impression.
- Head shape and material: according to the different methods, hardened steel pin have different pin and ball version.
| standard | ISO 7619-1 | ASTM D2240 |
| Sample thickness | 6 mm | 6 mm |
| The layer number | Is (layer 3) | is |
| measurement | 5 | 5 |
| The measured distance | 6 mm | 6 mm |
| Test of time | Vulcanized rubber for 3 s, TPE for 15 s |
Less than 1 s |
| load | Shaw hardness A is 1 kg, Shaw hardness D is 5 kg |
1 kg |
| Hardness specification | 54 shaw hardness A 3 s 54 shaw hardness A 15 s |
A / 54/1 A / 54/15 |
Shaw hardness test procedures
forISO 7619-1 standard shaw hardness test method, must consider the following parameters:
- In order to determine the hardness of the material, the standard must be measured in five times, and then calculate their average.
- Test time for 15 s.If you use other test time, you must indicate in the hardness value.
- Material under test shall be in 23 ° C + + 2 ° C for at least an hour at room temperature.
In the first step in the test, with 1.11 44.5 N spring force to press the head into the sample, and then use 3.92-50 N contact force will head pressure on the sample for 15 seconds.Sample of the indentation depth is between 0 and 2.5 mm.Hardness tester was used to measure the penetration depth, and thus it is concluded that the hardness value.head应以完全接触力作用于试样，持续时间为15秒。如果超过或未达到施加力的这一持续时间，则必须在硬度值中标明。持续时间越长，邵氏硬度值越低。
Keep the test point of minimum distance must be in accordance with the standards.Indentation should be 5 mm or higher, center distance between the distance to the edge of the specimen should be 12 mm or more.
Shaw hardness test method
The difference between each method:
- The shape of the head (as shown in figure)
- The size of the spring force F
- The size of the contact force FA
Using seven different pressure head and four different levels of contact force, can produce different test methods.More detailed information about the differences between each method, please see the table below.
methods |
Spring force F [N] |
The contact force Fa.[N] |
head |
Measure the t (mm) |
Sample thickness/mm |
range |
Shaw hardness a. |
8.050 N |
9.81 N |
Truncated cone, 35 ° Angle |
2.5 |
6 or higher |
10...90 < 20 D shaw hardness |
Shaw hardness A0 or shaw hardness E |
8.050 N |
9.81 N |
Spherical, Ø 2.5 mm |
2.5 |
6 or higher |
< 20 shaw hardness A |
Shaw hardness AM or shaw hardness M |
0.764 N |
9.81 N |
Taper Angle of 30 ° |
1.25 |
1.25 or higher |
10...90 |
Shaw hardness B |
8.065 N |
9.81 N |
Taper Angle of 30 ° |
2.5 |
6 or higher |
10...90 |
Shaw hardness C |
44.5 N |
49.0 N |
35 ° truncated cone, cone Angle, the truncated cone diameter of 0.79 mm |
2.5 |
6 or higher |
10...90 |
Shaw hardness D |
44.5 N |
49.0 N |
Taper Angle of 30 ° |
2.5 |
6 or higher |
30...Shaw hardness 90 > 90 A |
Shaw hardness D0 |
44.5 N |
49.0 N |
Spherical, Ø 3/32" |
2.5 |
6 or higher |
10...90 |
Shaw hardness 0 |
8.05 N |
9.81 N |
Spherical, Ø 3/32" |
2.5 |
6 or higher |
10...90 |
How to read and the hardness value?
Shaw testHardness value includes three main parts:
- 1. The numerical hardness value
- 2. The word "shaw", said shaw hardness
- 3. This method of naming, defines the pressure head and the related parameters
If time is different from standard, will represent the fourth part for additional time.
The method of presentation and hardness value sample:
| 75 shaw hardness 10 A | |
|---|---|
| 75 | ...Hardness value |
| Shaw hardness | ...According to shaw hardness |
| a. | ...Shaw method of truncated cone (35 ° Angle), spring force 8.065 N, contact force 12.5 N |
| 10 | ...Suggested that the duration of the contact force outside of time, in this case for 10 seconds |
