1、Designation: D1414 94 (Reapproved 2013)D1414 15Standard Test Methods forRubber O-Rings1This standard is issued under the fixed designation D1414; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods describe the procedures for determinin
3、g the physical properties of O-rings and changes in theseproperties due to aging.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated
4、 with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D297 Test Methods for Rubber ProductsChemical AnalysisD395 Test Me
5、thods for Rubber PropertyCompression SetD412 Test Methods for Vulcanized Rubber and Thermoplastic ElastomersTensionD471 Test Method for Rubber PropertyEffect of LiquidsD573 Test Method for RubberDeterioration in an Air OvenD865 Test Method for RubberDeterioration by Heating in Air (Test Tube Enclosu
6、re)D1329 Test Method for Evaluating Rubber PropertyRetraction at Lower Temperatures (TR Test)D1415 Test Method for Rubber PropertyInternational HardnessD2240 Test Method for Rubber PropertyDurometer HardnessD3767 Practice for RubberMeasurement of DimensionsD4483 Practice for Evaluating Precision for
7、 Test Method Standards in the Rubber and Carbon Black Manufacturing IndustriesE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 Aerospace Standard:AS568A Oring Sizes33. Terminology3.1 Definitions:3.1.1 O-ringa rubber seal of homogeneous composition
8、molded in one piece to the configuration of a torus with circular crosssection. The O-ring is used as a dynamic or static seal usually installed in a machined groove.4. Significance and Use4.1 These test methods provide acceptable procedures for quality control purposes and for the determination of
9、engineeringcharacteristics.1 These test methods are under the jurisdiction of ASTM Committee D11 on Rubber and are the direct responsibility of Subcommittee D11.37 on Coated Fabrics, RubberThreads and Seals.Current edition approved Nov. 1, 2013July 1, 2015. Published January 2014September 2015. Orig
10、inally approved in 1956. Last previous edition approved in 20082013as D1414 94 (2008).(2013). DOI: 10.1520/D1414-94R13.10.1520/D1414-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume inf
11、ormation, refer to the standards Document Summary page on the ASTM website.3 Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indic
12、ation of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be co
13、nsidered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. General Methods5.1 Except as otherwise specified in these test methods for rubber O-rings, the following ASTM test methods applicable ingeneral to vulca
14、nized rubber, shall be complied with as required and are hereby made a part of these test methods:5.1.1 Tension TestTest Methods D412.5.1.2 Compression SetTest Methods D395.5.1.3 Low TemperatureTest Method D1329.5.1.4 DensityTest Methods D297.5.1.5 Fluid AgingTest Method D471.5.1.6 Heat AgingTest Me
15、thods D865 and D573.5.1.7 HardnessTest Methods D2240 and D1415.5.2 In case of conflict between the provisions of these test methods and those of detailed procedures herein, the latter shall takeprecedence.6. Test Conditions6.1 The temperature of the testing room shall be 23 6 2C (73.4 6 3.6F). The s
16、pecimens to be tested shall be kept in this roomfor a minimum of 30 min previous to the time of testing. For referee tests the minimum time for conditioning shall be 16 h. Incases where this temperature cannot be obtained, the actual temperature shall be reported.7. Dimensional Measurements7.1 Thick
17、ness:7.1.1 The thickness or cross section mayshall be measured by one of the following methods: (a) a hand micrometer equippedwith 6-mm micrometer in accordance with Practice D3767(0.25-in.) diameter hemispherical tips (ballpoint or tubing micrometers),(, ProcedureA.b) dial indicators that have a ma
18、ximum contact force of 0.29 N (29 gf), or (c) an electronic micrometer with a springforce of 0.1 N (10 gf) maximum. Better accuracy can be obtained with a 0.05-N (5-gf) spring or with no spring. In case of refereetests, both laboratories shall use the same spring force.7.1.2 The O-ring specimen shal
19、l be measured at four points equally distributed around the circumference in both the radial andaxial direction. An average reading shall be used for calculation.7.2 DiameterA stepped cone or optical comparator may be used for measuring the inside diameter of small rings. Thediametric intervals of t
20、he stepped cone shall not exceed 2 % of the diameter to be measured (see Fig. 1).FIG. 1 Stepped Cone GageD1414 1528. Tension Testing8.1 Testing Machine The testing machine shall conform to the requirements specified in Section 3 of Test Methods D412, withthe exception of the grips. Grips for testing
21、 rings shall consist of ball-bearing spools at least 9 mm (0.35 in.) in diameter, and becapable of being brought within 19 mm (0.75 in.) center-to-center distance at closest approach. Stresses within the specimen shallbe minimized by (1) rotating one spool one full revolution for each 150 mm (6.0 in
22、.) of travel of the power-driven grips or (2)lubricating the contact surface of the spools with castor oil. Grips for testing straight specimens may be of any type provided breaksdo not occur in a portion of the specimen that has been at any time in contact with the grips. For specimens smaller than
23、 25 mm(1 in.) in inside diameter, spools of smaller diameter and closer approach may be employed.8.2 Test Specimen:8.2.1 The test specimen shall consist of an entire O-ring except in the following cases: (1) when the diameter is too large topermit a break within the limits of travel of the testing m
24、achine, (2) when the specimen has been previously cut open to permitan aging test, and (3) when the specimen is unaged but is to be compared with an aged specimen as described in (2). For thesecases a specimen cut from a ring shall be employed.8.2.2 Specimens that exhibit obvious flaws at any point
25、on the surface, such as might result from imperfect molding or flashremoval, shall not be tested.8.3 Procedure for Determination of Tensile Strength, Ultimate Elongation, and Tensile Stress:8.3.1 Bring the grips close enough together so the specimen can be installed without stretching. Set the machi
26、ne for a speed of500 6 50 mm (20 6 2 in.)/min, set the chart recorder, and engage the clutch. (If a recorder is not used, note the spoolcenter-to-center distance continually by means of a suitable scale). The stressed inside circumference, L, is equal to twice thedistance between spools plus the cir
27、cumference of one spool. Record the breaking force value, F, at the elongation specified fortensile stress and at the time of rupture. Measure the center-to-center distance between the spools at rupture to the nearest 2.5 mm(0.1 in.) and record as the value for D.8.3.2 For the application of bench m
28、arks to segmented specimens as described in 8.2, hold the piece as straight as possible beingcareful not to apply excessive stress. Follow the procedure described in 8.3.1. Discard results for any specimen that breaks at apoint that has at any time contacted the grip, and test an additional specimen
29、. A suitable extensiometer may be employed forelongation determination.8.4 Calculations:8.4.1 Tensile Strength Calculate the tensile strength as follows:8.4.1.1 For O-rings on spool grips:T 5F/A (1)where:T = tensile strength,F = breaking force, andA = twice the cross-sectional area calculated from a
30、xial thickness, W, as follows:A 5piW 2/251.57 W 2 (2)therefore:T 5F/1.57 W 2 (3)8.4.1.2 For straight or single-strand specimens:A 50.785 W 2 (4)T 5F/0.785 W 2 (5)8.4.2 Ultimate ElongationCalculate the ultimate elongation as follows:8.4.2.1 For rings:Ultimate elongation,%52D1G 2C!/C# 3100 (6)where:D
31、= distance between centers of the spool grips at the time of rupture of specimen,G = circumference of one spool (spool diameter 3.14), andC = inside circumference of the specimen (or inside diameter 3.14).8.4.2.2 For straight or single-strand specimen cut from an O-ring:Ultimate elongation, %5L 2L o
32、!/Lo# 3100 (7)where:L = observed distance between bench marks of stressed specimen, andD1414 153Lo = original distance between bench marks.8.4.3 Tensile Stress Calculate the tensile stress as in the case of tensile strength except the stress is reported at a predeterminedelongation below the ultimat
33、e elongation. Calculate the center-to-center distance of the spool grips, D, where the prescribedelongation, E, occurs, as follows:D 51/2EC/100!1C 2G# (8)NOTE 1This value of tensile stress at a predetermined elongation is based upon inside circumference and differs from that determined byTest Method
34、sD412, which is based on the mean circumference.8.5 Characteristics of Sample TestedThe median of the values for three specimens shall be taken as the characteristics of thesample tested, except that under the following conditions the median of the values for five specimens (two additional) shall be
35、 used:8.5.1 If one or more values do not meet the specified requirements when testing for compliance with specifications.8.5.2 If referee tests are being made.8.6 Report:8.6.1 The report shall include the following:8.6.1.1 Results calculated as in 8.4,8.6.1.2 Date of test,8.6.1.3 Temperature of test
36、 room if other than provided for in Section 6,8.6.1.4 Type of testing machine used, including diameter of spool grip if other than standard, and speed, if other than 8.36 0.8mm (20.0 6 2 in.)/min, and8.6.1.5 Type of specimen (ring or straight).9. Tension Set Test9.1 Procedure:9.1.1 Stretch the O-rin
37、g specimens to 100 % elongation and hold at this strain for 10 min. At the end of this period release thespecimen and allow it to recover for 10 min. At the end of this recovery period, measure the inside diameter with a step gagereference in 7.2 and shown in Fig. 1.9.1.2 Apply the strain by (1) str
38、etching the specimen over a tapered cone which has a step at the required 100 % elongation,or (2) by means of a tension test machine stopping the machine at 100 % elongation, or ( 3) by the use of any special fixture capableof holding the O-ring over two spools at constant distance between spool cen
39、ters.9.2 Calculation Calculate tension set as follows:Tension set,%5L12L o!/Lo# 3100 (9)where:L 1 = diameter after testing, andLo = original diameter.9.3 Straight specimens cut from large O-rings may be tested and calculated in accordance with Test Methods D412.10. Compression Set Test10.1 Nature of
40、 Test The compression set of O-ring specimens shall follow the general procedures of Method B of TestMethods D395, with the following exceptions:10.2 Apparatus:10.2.1 SpacersThe spacers shall be adjusted to within 0.025 mm (0.01 in.). This can be done by employing shim stock ofvarious thickness.10.2
41、.2 Measurement The cross section before and after test shall be measured in the same marked location with a ball-point(tubing) micrometer or other method as described in 7.1.10.3 Test Specimen The specimen shall be a suitable section cut from the sample O-ring. A52-mm (2-in.) section has beenfound t
42、o be satisfactory on sample O-rings of 17-mm (0.67-in.) or larger inside diameter. On smaller O-rings, a section ofapproximately 3 mm (18 in.) shall be cut from the sample and discarded.NOTE 2Testing a whole O-ring for compression set is always avoided because air trapped inside the O-ring results i
43、n a different set of conditionson the inside and outside surface of the specimen.10.4 ProcedureMeasure the actual specimen to within 0.025 mm (0.001 in.) and calculate the spacer to be 75 % of thisthickness, to within 0.025 mm (0.001 in.). Close the plates, employing a sufficient number of bolts to
44、prevent deflection uponheating.At the end of the heating period, release the plates as soon as possible and allow the specimens to cool to room temperatureunder the conditions described in Test Methods D395.D1414 15411. Compression Set in Liquids11.1 Compression set may be conducted immersed in any
45、liquid provided a suitable container is available. The container needsto be large enough to hold the plates and withstand the vapor pressure of the liquid at test temperature.11.2 The specimen is prepared in accordance with 10.3, and at the termination of the heating period the plates are releasedim
46、mediately and the specimens are allowed to cool to room temperature for 30 min in a fresh cool portion of the test liquid.Measurement and reporting are the same except the type of liquid is listed in the report.12. Low-Temperature Test12.1 Nature of Test The TR-10 or Temperature Retraction Test shal
47、l be in accordance with Test Method D1329 with theexceptions given in 12.2 to 12.4.12.2 Test Specimen The test specimen shall be an O-ring of 1.5 to 3.8-mm (0.06 to 0.15-in.) cross-sectional diameter and ofsufficient length to reach from clamp to clamp when the ring is cut and held in straight posit
48、ion.12.3 ProcedureStretch the mounted specimen 50 % as standard. If a greater or lesser stretch is used, report the actual stretch.12.4 ReportThe report shall include the following:12.4.1 Testing elongation, in percent, and12.4.2 Temperature at which the specimen retracts 10 %, designated as TR-10 a
49、nd at other points, such as 30, 50, or 70 %, orall, if required.13. Relative Density Test13.1 Test Specimen Any O-ring, O-rings, or segment of an O-ring may be considered as the specimen. The minimum massof the specimen shall be 0.005 N (0.5 gf). In the case of very small O-rings, two or more pieces may be used as the specimen toaccomplish this total minimum mass.13.2 ProcedureEmploy the procedure outlined in Test Methods D297, density hydrostatic method.NOTE 3Extreme accuracy is required in making relative density determi
