These test methods allow for the measure- 6. However, tensile properties vertically near the grips or spindles for conditioning prior to alone may not directly relate to the total end use performance test. The specimens shall not touch each other or the sides of of the product because of the wide range of potential perfor- the chamber except for momentary contact when agitated by mance requirements in actual use.
These effects will vary depending on the type of material being 6. If a scale is used to measure the 5. For this reason, the periods of extension and and shall be controlled from outside the chamber. For ring specimens, see Apparatus 6. The testing provided. If the capacity range cannot be changed for a test 7. If the dynamometer is of the compensating type 7.
The influence on tensile properties, dumbbell or straight specimens response of the recorder shall be sufficiently rapid that the should be cut so the lengthwise direction of the specimen is. For obtaining non-rupture stress-strain or material moplastic elastomer specimens, or both, are to be cut from modulus properties, straight specimens are quite useful.
Specimens of other thickness will not necessarily give the material, test equipment and the sample or piece available comparable results. Specimens are to be tested in directions for test. A longer specimen may be used for rubbers having low both parallel and perpendicular to the direction of flow in the ultimate elongation to improve precision of elongation mea- mold.
Sheet or plaque dimensions must be sufficient to do this. Calibration of the Testing Machine the ring specimens is not uniform. To minimize this effect the 8. If the dynamometer is of the strain-gage diameter. Apparatus 8. The inside faces in the reduced section shall be 8. The die shall at all times be sharp and free of specimen grip mechanism in such a way as to permit the mass nicks see 9. Remove 8. Rupture consistently at the same place indicates that the die may be dull, 8.
Ensure that the mass of the lower grip marks see Note 4. The bench marker shall consist of a base mechanism and the hook are included as part of the known plate containing two raised parallel projections. The surfaces of mass. The raised projection removed, recalibrate the testing machine at a minimum of three marking surfaces shall be between 0. If pawls or rachets are used during angles between the parallel marking surfaces and the sides of routine testing, use them for calibration. Check for friction in the projections shall be at least The distance between the the head by calibrating with the pawls up.
A NOTE 3It is advisable to provide a means for preventing the known handle attached to the back or top of the bench marker base mass from falling to the floor in case the dumbbell should break.
Test Temperature metal, or plastic shall be used to apply either ink or powder to 9. The ink or powder shall adhere to the testing shall be 23 6 2C Specimens shall be specimen, have no deteriorating effect on the specimen and be conditioned for at least 3 h when the test temperature is 23C of contrasting color to that of the specimen. If the material is affected by moisture, maintain the When testing at any other Constant pressure pneumatic type grips also Method B see Note 3.
Place each specimen in the test are satisfactory. At the end of each grip a positioning device is chamber at intervals ahead of testing so that all specimens of a recommended for inserting specimens to the same depth in the series will be in the chamber the same length of time. The grip and for alignment with the direction of pull. WarningIn ad- pressure pneumatic, wedged, or toggle type designed to trans- dition to other precautions, suitable heat or cold resistant mit the applied gripping force over the entire width of the gloves should be worn for arm and hand protection when gripped specimen.
A mask for the face is very desirable for high temperature testing to prevent the inhalation Specimens of toxic fumes when the door of the chamber is open.
Sheets may be mens shall be marked with the bench marker described in Marks cutting and buffing. If obtained from a manufactured article, shall be placed on the reduced section, equidistant from its the specimen shall be free of surface roughness, fabric layers, center and perpendicular to the longitudinal axis. The between etc. All specimens shall be cut so that the lengthwise Fig. In the case of sheets prepared in accor- The median grain. Use Die C, Fig. Specimens with a differ- machine to ensure smooth cut surfaces.
Dies dimensioned in metric units are intended for use with apparatus calibrated in metric units. B For dies used in clicking machines it is preferable that this tolerance be B For dies used in clicking machines it is preferable that this tolerance by The width section.
This avoids complications that prevent the maximum of the specimen shall be taken as the distance between the strength of the material from being evaluated.
Unless otherwise cutting edges of the die in the restricted section. Start the machine and note the pared if it is not practical to cut either a dumbbell or a ring distance between the bench marks, taking care to avoid specimen as in the case of a narrow strip, small tubing or parallax.
Record the force at the elongation s specified for the narrow electrical insulation material. These specimens shall be test and at the time of rupture. The elongation measurement is of sufficient length to permit their insertion in the grips used for made preferably through the use of an extensometer, an the test.
Bench marks shall be placed on the specimens as autographic mechanism or a spark mechanism. At rupture, described for dumbbell specimens in See cross sectional area of straight specimens in the form of tubes, Section 13 for calculations. The actual rate of where: separation shall be reported. Sepa- rate the grips at a rate of speed as uniformly as possible, that Procedure requires 15 s to reach the specified elongation.
Hold the At the end of the 10 min rest symmetrically to distribute tension uniformly over the cross period, measure the distance between the bench marks to the. Use See Section 13 for individual test measurement values for any of the measured calculations. There are Measure the distance between the See Section 13 for calculations. Calculation Apparatus All the magnitude, where the rate of change of stress with respect to holes shall connect to a central internal cavity which can be strain, goes through a zero value.
The cutter rotator device shall be mounted on a horizontal base and have a vertical support orientation for the where: shaft that rotates the spindle and cutter.
L is equal to the distance between bench marks at the point of Bench marks shall be placed on the specimens as described for dumbbell specimens in To determine the cross sectional area of straight specimens in the form of tubes, the mass, length, and density of the specimen may be required. The actual rate of separation shall be reported. Separate the grips at a rate of speed as uniformly as possible, that requires 15 s to reach the specified elongation.
Hold the specimen at the specified elongation for 10 min, release quickly without allowing it to snap back and allow the specimen to rest for 10 min. Procedure There are two exceptions to this and for these exceptions a total of five specimens measurements shall be tested and the test result reported as the median of five. Use a stop watch for the timing operations. Measure the distance between the bench marks.
Calculation This is used for cutting rings from flat sheets by mounting the upper shaft portion of the cutter in a rotating housing that can be lowered onto a sheet held by the rubber holding plate as shown in Fig. See Fig. All the holes shall connect to a central internal cavity which can be maintained at a reduced pressure for holding the sheet in place due to atmospheric pressure.
The cutter rotator device shall be mounted on a horizontal base and have a vertical support orientation for the shaft that rotates the spindle and cutter. The run-out of the rotating spindle shall not exceed 0. The testing machine shall be calibrated as outlined in Section 8.
Ring Specimen However at extreme temperatures, a suitable lubricant shall be used to lubricate the spindle bearings. To accommodate small diameter rings that approach the This permits placing small rings on the upper cylindrical surface without interference fit problems. Curved feet on the end of the dial micrometer shaft to fit the curvature of the ring s , may be used. Unless otherwise specified, the Type 1 ring specimen shall be used. See ISO 37 for specific testing procedures for these rings.
Dimension mm in. Place the cutter in the drill press and adjust the spindle or table so that the bottom of the blade holder is about 13 mm 0. Set the stop on the vertical travel of the spindle so that the tips of the cutting blades just penetrate the surface of the plate. Place the sheet on the holding plate and reduce the pressure in the cavity to 10 kPa 0.
Lubricate the sheet with mild soap solution. Lower the cutter at a steady rate until it Small 8. For below room temperature tests cool the specimens at the test temperature for at least 10 min prior to test.
Use test temperatures prescribed in Practice D Place each specimen in the test chamber at intervals such that the recommendations of 9. Be sure that the blade holder does not contact the sheet.
If necessary, readjust the blade depth. Return the spindle to its original position and repeat the operation on another sheet. Rotate the mandrel and tubing in a lathe. Cut ring specimens to the desired axial length by means of a knife or razor blade held in the tool post of the lathe. Lay thin wall tubing flat and cut ring specimens with a die or cutting mechanism having two parallel blades. Do not use any stress in excess of that needed to overcome any ellipticity of the ring specimen. The mean circumference is obtained by adding to the value for the inside circumference, the product of the radial width and p 3.
For thin wall tubing, the area is calculated from the axial length of the cut section and wall thickness. Extending a ring specimen generates a nonuniform stress or strain field across the width as viewed from left to right of each leg of the ring.
The initial inside dimension circumference is less than the outside dimension circumference , therefore for any extension of the grips, the inside strain or stress is greater than the outside strain or stress because of the differences in the initial unstrained dimensions. The rationale for this choice is that the mean circumference best represents the average strain in each leg of the ring. This location is the most probable site for the initiation of the rupture process that occurs at break.
Select one with documented assurance that it does not interact or affect the material being tested. Start the test machine and record the force and corresponding distance between the spindles. At rupture, measure and record the ultimate breaking elongation and the tensile force strength.
See Section 17 for calculations. Since yield strain may be considered to be an average bulk property of any material, use the mean circumference for this evaluation. The appropriate value is that value of r or R associated with a mean level in Tables closest to the mean level under consideration at any given time, for any given material in routine testing operations.
Two single test results, obtained under normal test method procedures, that differ by more than this tabulated r for any given level must be considered as derived from different or nonidentical sample populations. Two single test results obtained in two different laboratories, under normal test method procedures, that differ by more than the tabulated R for any given level must be considered to have come from different or nonidentical sample populations.
For the r and R statements, the difference in the two single test results is expressed as a percentage of the arithmetic mean of the two test results. Reference values do not exist for this test method since the value of the test property is exclusively defined by the test method.
Bias, therefore, cannot be determined. Both repeatability and reproducibility are short term, a period of a few days separates replicate test results. A test result is the mean value, as specified by this test method, obtained on three determinations or measurements of the property or parameter in question. Use the inside diameter to calculate the inside circumference for Type 2 rings.
NOTE 9—Eq 8, Eq 9, and 10 are applicable only if the initial setting of the spindle centers is adjusted in accordance with Eq 7. NOTE 10—The user of these test method should be aware that because of the different dimensions used in calculating 1 stress at a specified elongation less than the ultimate elongation and 2 the ultimate breaking elongation see Report Customary Units or Metric Units, was used.
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