1、Designation: F2819 10Standard Test Methods forMeasurement of Straightness of Bar, Rod, Tubing and Wireto be used for Medical Devices1This standard is issued under the fixed designation F2819; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This standard covers the various test methods to be usedfor measurement of straightness of bar, r
3、od, tubing, and wire.These test methods apply primarily to bar, rod, tubing, and wirethat are ordered in the straightened and cut-to-length condition.It also applies to small diameter tubing and wire that has beenspecially processed to roll off a spool in the straightenedcondition.1.2 These test met
4、hods apply to straightness of round wirethat has a diameter between 0.05 and 4.78 mm (0.002 and0.188 in.). They also apply to flatness (camber) of flat-shapedwire or ribbon with a maximum dimension between 0.05 and4.78 mm (0.002 and 0.188 in.). For flatness (camber) measure-ment, refer to Test Metho
5、d F2754/F2754M.NOTE 1The current version of Test Method F2754/F2754M covers adifferent diameter range (0.0127 to 4.78 mm (0.0005 to 0.188 in.) anddoes not include superelastic NiTi. These exceptions would not affect thecamber measurement as conducted by Test Method F2754/F2754M.1.3 These test method
6、s apply to straightness of round tubingthat has an outer diameter between 0.05 and 6.35 mm (0.002and 0.25 in.).1.4 These test methods apply to straightness of round rodthat has a diameter between 4.78 and 6.35 mm (0.188 and 0.25in). It also applies to flatness (camber) of flat and shaped rodwith a m
7、aximum dimension between 4.78 and 6.35 mm (0.188and 0.25 in). For measurement of flatness (camber), refer toTest Method F2754/F2754M.NOTE 2The current version of Test Method F2754/F2754M covers adifferent diameter range (0.0127 to 4.78 mm (0.0005 to 0.188 in.) anddoes not include superelastic NiTi.
8、These exceptions would not affect thecamber measurement as conducted by Test Method F2754/F2754M.1.5 These test methods apply to straightness of round barthat has a diameter between 6.35 and 101.6 mm (0.25 and 4 in).It also applies to flatness (camber) of flat and shaped bar witha maximum dimension
9、between 6.35 and 101.6 mm (0.25 and4 in). For measurement of flatness (camber), refer to TestMethod F2754/F2754M.NOTE 3The current version of Test Method F2754/F2754M covers adifferent diameter range (0.0127 to 4.78 mm (0.0005 to 0.188 in.) anddoes not include superelastic NiTi. These exceptions wou
10、ld not affect thecamber measurement as conducted by Test Method F2754/F2754M.1.6 These test methods apply to ferrous and non-ferrousalloys including linear-elastic or superelastic nitinol. Refer toTerminology F2005 for more details on NiTi terminology.1.7 The values stated in either SI units or inch
11、-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.8 This standard does not purport
12、to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F2005 T
13、erminology for Nickel-Titanium Shape MemoryAlloysF2754/F2754M Test Method for Measurement of Camber,Cast, Helix and Direction of Helix of Coiled Wire2.2 Other Standards:3GGG-P-463 U.S. Federal Specification: Plate, Surface(Granite)3. Terminology3.1 Fig. 1 and Fig. 2 show the physical meaning ofstrai
14、ghtness. Fig. 3 shows the definition of wobble in a straightwire as it is being rotated.1These test methods are under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.15 on Material Test Methods.Current edition ap
15、proved Dec. 15, 2010. Published January 2011 DOI: 10.1520/F281910.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM web
16、site.3Available from IHS, 321 Inverness Drive South Englewood, CO 80112,http:/.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This Standard:3.2.1 straightnessDeviation of an axis or surface eleme
17、ntfrom linearity over a unit length in the unloaded (force andmoment free) condition.Aperfectly straight condition is shownin Fig. 1. An unloaded condition is shown in Fig. 2.3.2.2 wobbleElliptical rotation observed in a small diam-eter wire or tube as it is being rotated around a central axis asis
18、shown in Fig. 3.4. Summary of Test Method4.1 For bar, rod, tube, and wire, the deviation from thecondition of resting flat on a smooth surface can be measuredby using a quantitative or qualitative test method. Two quan-titative and two qualitative methods are the gap and TIR (TotalIndicator Readout)
19、 and inclined flat plate and finger roll tests,respectively4.2 Inclined Flat Plate Test (qualitative test method that canbe made quantitative)A common method for measurementof straightness of wire or tubing with a diameter less than 4.78mm (0.188 in.) is the inclined flat plate test. In this method,
20、 asectioned piece of material is allowed to roll down an inclinedtable as is illustrated by Fig. 4 and Fig. 5. The material passesthe test if it rolls freely down the table l without stopping as isshown by Fig. 5.4.3 Finger-Roll Test (qualitative test method)A secondcommon method for measurement of
21、straightness that is usedfor wire and tubing with a diameter less than 0.25 mm (0.010in.) is the finger-roll test. In this test, a cut length of wire ortubing is laid on a flat surface. A finger, pencil, pen, or plasticcard is used to rotate the center of the sample back and forth onthe flat surface
22、. The opposite ends of the sample should rotatesmoothly without wobble as is defined in 3.2.2 of these testmethods.4.4 Gap Test (quantitative test method)A common quan-titative method for measurement of straightness of wire with adiameter less than 4.78 mm (0.188 in.) is the gap test. It canFIG. 1 D
23、efinition of a “Straight” ConditionFIG. 2 Definition of a “Nonstraight” ConditionFIG. 3 Definition of Wobble in a Small Diameter Tube or Wire as it is Being RotatedF2819 102also be used for rod with a diameter between 4.78 and 6.35 mm(0.188 and 0.25 in.), tubing with diameter 0.05 to 6.35 mm(0.0002
24、to 0.25 in.) or bar with a diameter between 6.35 to101.7 mm (0.25 to 4 in.), the gap test can be used to measurestraightness. The gap test can also be used for flat or shapedwire and ribbon. In this method, a thickness gauge equal to thegap must not fit between the rod, tubing, or bar and flat surfa
25、ceat any point along its length when rolled or rotated 360. Thegap defines the straightness of the rod, tubing, or bar.4.5 Total Indicator Readout (TIR) test (quantitative testmethod)In this method, a round rod with a diameter between4.78 and 6.35 mm (0.188 and 0.25 in.) or round bar with adiameter
26、between 6.35 to 101.7 mm (0.25 to 4 in.), is placed ontwo or more V-blocks. The test specimen is then rotated onerevolution between two or more V-blocks that are a fixeddistance (d) apart while measuring in the center with anindicator. Total Indicator Readout (TIR) in the test specimen isthen calcul
27、ated.5. Significance and Use5.1 SignificanceWith the birth of minimally invasivesurgery in the 1960s, there has been a requirement for guidewires. The guide wires serve as the access line by whichprocedures like balloon angioplasty and stent placement areconducted. A guide wire typically consists of
28、 a mandrel, coiland in some cases a safety wire is used. The market for guidewires continues to grow as the number of procedures increases.For successful manufacturing of guide wires, linearity orstraightness of 304 stainless steel and nitinol wire that is usedfor the manufacture of guide wire mandr
29、els is critical to theirend use performance. Users of guide wires require that theymust navigate a tortuous anatomy.5.1.1 A second part of minimally invasive surgery is the useof machined or formed wire, tube, or rod. In this case,straightness of rod, tube, and wire that is going to be machinedor su
30、bjected to a forming practice such as bending needs to bevery linear or straight so it is accurately fed into the equipmentthat is used for the machining or forming practice. Lasermachining is an example of a machining operation that requiresa wobble-free piece of rod, tubing, or wire so that it can
31、 beproperly fed into the alignment bushings of the laser. Wireforming equipment also requires wobble-free material for thesame reason.5.2 UseThese test methods can be used by users andproducers of medical grade bar, rod, tubing, and wire to specifyrequirements to evaluate and confirm the straightnes
32、s ofmaterial. Depending upon the type of material and its metal-lurgical condition, it may be possible to reprocess the materialto reduce its non-linearity.6. Apparatus6.1 For the inclined flat plate test, a flat table preferablymade of granite that can be precisely inclined is required. Theflat tab
33、le should have an inspection grade; grade A, flatness asset forth by Federal Specification GGG-P-463. A precisemeasurement device and a protractor are also required. Ex-amples of precise measurement devices that can be used arethickness gauges, gauge pins, micrometer, or a linear scale.Fig. 4 and Fi
34、g. 5 show the equipment used for the roll test.NOTE 4A parallel can be used but it is optional.FIG. 4 Example of a Table and Granite Parallel Used to Measure Straightness by the Roll TestFIG. 5 Example of Inclined Surface Table and Protractor Used to Measure Straightness by the Roll Test MethodF2819
35、 1036.2 For the finger roll test, a precision flat surface such as abench or table is required. The surface of the bench or tableshould not be pitted, gouged, cracked, and so forth, but be ingood condition.6.3 For the gap test, a precision flat surface such as a benchor table is required. For heavy
36、test specimens such as bar, thefloor can be used. The surface of the bench, table, or floorshould not be pitted, gouged, cracked, and so forth, but be ingood condition. A measurement device such as a thicknessgauge, gauge pin, micrometer, optical comparator, or a linearscale may be used to determine
37、 the gap. The deviation fromflatness of the flat surface shall be at least one order ofmagnitude less than the straightness requirement of bar, rod,wire, or tubing that is going to be inspected.6.4 For the TIR test, a dial indicator and two or moreV-blocks are required.7. Hazards7.1 Ends of cut bar,
38、 rod, tube, and wire can be sharp. Cutpieces of material need to be handled with care. It may benecessary to wear gloves in order to avoid being injured.7.2 A pinch point exists between the inclined table andparallel. Caution and safety precautions are required in order toavoid pinch point injuries.
39、7.3 Safety glasses and proper cutting techniques should beused when creating the test sample. Cutters should be in thesharpened condition.8. Sampling, Test Specimens, and Test Units8.1 The test sample for the finger roll and inclined flat platetests shall consist of a minimum of 0.25 m (10 in.) cut
40、piece oftubing or wire. The test sample for the gap and TIR tests shallconsist of a 0.25 6 0.02 m (10 6 1 in.) cut piece of rod ortubing, bars, or wire.8.2 The number of test specimens shall be agreed uponbetween the customer and supplier.8.3 Whether or not the test specimens are cut from the sameor
41、 separate pieces of straightened and cut to length, rod, tube,or wire or spools, shall be agreed upon between the customerand supplier.8.4 For small diameter wire and tubing, the straightened-to-length wire or tubing or spool, the test sample shall besectioned from the lot by using a sharp cutter to
42、 ensure a burrfree edge after the cutting process. For larger diameter rod,tubing, and wire, an abrasive cut off or diamond blade sawshall be used to ensure a burr free edge and that the edge wasnot permanently deformed during the cutting process.8.5 For superelastic NiTi wire, tube, or rod, the str
43、aightnessshould be measured when the material is in the fully super-elastic condition. If the austenite finish temperature (Af)ofthetest sample is greater than the temperature of the environment,the sample should be preheated to a temperature greater thanthe austenite finish temperature (Af)9. Prepa
44、ration of Apparatus9.1 For the inclined flat plate test, the surfaces of the plateand parallel shall be clean and not damaged. For the finger rolland gap tests, the flat surface used for the inspection shall beclean and not damaged. For the TIR test, the V-blocks shouldbe clean and in good condition
45、.10. Calibration and Standardization10.1 All measurement devices used in the test procedureincluding precision surface plates, parallels, protractors, thick-ness gauges, gauge pins, micrometers, or linear scales, shouldbe in calibration as defined by company quality assurancepolicy.11. Procedure11.1
46、 Inclined Flat Plate Test (qualitative test method):11.1.1 Ensure that the plate is clean, free of debris, and freeof damage. Optional: if a parallel is used, ensure that it is clean,free of debris, and free of damage.11.1.2 OptionalIf a parallel is used, place parallel on thetable and elevate it to
47、 a height above the table that is equal tothe rod, tube, or wire diameter plus an acceptable maximumtolerance to be agreed upon by the customer or supplier. Thiscan be done using gauge pins, thickness gauges, a micrometer,or linear scale (see Fig. 4).11.1.3 With the aid of a protractor, incline the
48、table asshown in Fig. 5. For wire or tubing with a diameter less than0.50 mm (0.020 in.), the incline of the table is recommended tobe 40 or as agreed upon by the customer and the supplier. Forrod, tubing, or wire with a diameter greater than 0.50 mm(0.020 in.), the incline of the table is recommend
49、ed to be 2 oras agreed upon by the customer and the supplier.11.1.4 Rest the test sample at the end of the surface tableparallel to the edge and release it. If it does not roll, gentlytouch it with a pencil or other object in order to overcome staticfriction.11.1.5 The test sample passes the test if it rolls freely downthe incline without stopping.NOTE 5This test can be made quantitative by measuring the maxi-mum gap between the table and the inner surface of the wire, tubing, androd or the gap of the parallel and table.11.2 Finger Roll Test (q
