定价： 260元 / 折扣价： 221 元

AbstractFormerly under the jurisdiction of Committee F16 on Fasteners,this specification was withdrawn in May 2016 and replaced by Specification for High Strength Structural Bolts, Steeland Alloy Steel, Heat Treated, 120 ksi (830 MPa) and 150 ksi (1040MPa) Minimum Tensile Strength, Inch and Metric Dimensions. Specification supersedes and replaces specifications; A325, A325M, A490, A490M, F1852 and F2280. The unified Specification corrects known inconsistencies in the original documents and the combination will assure that requirements of the products covered under the original standards stay aligned. For referenced ASTM standards, visit the ASTM website, www.astm.org,or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’sDocument Summary page on ASTM website.

定价： 0元 / 折扣价： 0 元

4.1 The rectangular or square copper alloy tube covered by this test method may be used in applications in which control of twist is important to proper fit in final assembly and to minimize rework to bring the tube into compliance. It is recognized that the amount of twist, in degrees per increment of length, can change as a result of the weight of the product and its length during measurement.4.2 This test method provides a procedure for measuring the twist in square and rectangular copper and copper alloy tubes as a measure of the deviation from straightness.4.3 This test method allows the purchaser and supplier or manufacturer to inspect square and rectangular copper and copper alloy tube with a standard technique that provides acceptable twist in delivered tubes.1.1 This test method establishes the requirements for the determination of the angle of twist in rectangular and square copper and copper alloy tube.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 This test method is used for acceptance testing in the trade for economic reasons even though it is less accurate than the direct method, Test Method D1423.5.1.1 If there are differences or practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if their is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results are obtained, and that are assigned randomly in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.5.2 The “setting” of twist in some fibers causes excessive contraction when the yarn is retwisted in the reverse direction. Therefore, the number of turns required to bring the specimen back to its original length may be less than the number of turns removed in untwisting. This effect may be partially offset by the use of higher pretensioning loads; but this increases the danger of stretching the yarn. Little information is available on the correct tensions to use for yarns made from different fibers or with different amounts of twist.5.3 In addition to being less tedious, this test method requires fewer specimens than the direct-counting method and the results may be sufficiently accurate for certain purposes. This test method can be useful in those cases where the main objective is to measure variations from an average value. Another possible application is where a large amount of twist testing is required on yarns of similar type and twist. In this case preliminary tests comparing this method and the direct method could be used to determine the correct pretension.5.4 Twist has important effects on the physical properties of yarn. Low-twist yarn is lofty and is usually preferred for knitting because of its softness, covering power, and warmth. Increasing the amount of twist causes an increase in yarn strength by increasing fiber cohesion, but as the twist angle increases beyond an optimum point, strength decreases due to a loss in effective fiber contribution. Maximum yarn strength is obtained by inserting a medium amount of twist to obtain an optimum balance between these two opposing forces. High twist produces yarns of high density (“hard” or “wiry”) and high elongation and may improve the abrasion and impact resistance of fabrics.5.5 The optimum twist for either manufacturing efficiency or physical properties usually increases as staple length decreases.5.6 The twist in a yarn before it is packaged may be different from that of the yarn after it has been withdrawn from the package because of changes in tension and the effect of the method of withdrawal. Withdraw the yarn from the package in the direction of normal use, either from the side or over-end. If the yarn is withdrawn over-end, a slight increase or decrease in twist will take place, depending upon the direction of the twist in the yarn, the direction of winding on the package, and the length of the turn (or wrap) on the package.NOTE 2: The difference in twist between unwinding from the side and over-end is 1/πd, where d is the diameter of the package.4 Thus, for a 25-mm [1-in.] diameter package, the difference would be about 13 tpm or about one third tpi.5.7 When a yarn is taken from a more complex yarn structure or from a fabric, the resultant twist should be considered only an approximation of the original value because of alterations that may have occurred as a result of the effects of unwinding, handling, and mechanical strains met in processing.1.1 This test method2 describes the determination of twist in single spun yarns when only an approximation of the true twist is required.NOTE 1: For a more accurate method see Test Method D1423.1.2 This test method is applicable to spun single yarns in continuous lengths, and also to spun yarns raveled from fabrics, provided specimens at least 200 mm [8 in.] long can be obtained.1.3 This test method has been found satisfactory for use in determining the approximate twist content in single ring spun yarns of all types and fiber contents, but not in open-end spun yarns.1.4 This specification shows the values in both inch-pound units and SI units. The “inch-pound” units is the technically correct name for the customary units used in the United States. The “SI” units is the technically corrected name for the system of metric units known as the International System of Units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Test Method D1423 for testing twist in yarns by direct-counting is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable and the method has been used extensively in the trade for acceptance testing.5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum use the samples for such comparative tests as homogeneous as possible, drawn from the same lot of material that resulted in the disparate test results and randomly in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.5.2 The determination of twist in a straight section of a yarn is not the simple straightforward operation it appears to be, for the test results may be greatly influenced by variations in test procedures and techniques. In all manipulations, extreme care is necessary to prevent specimen rotation altering the twist level before testing begins.5.3 The twist in a yarn before it is packaged may be different from that of the yarn after it has been withdrawn from the package because of changes in tension and the effect of the method of withdrawal. If the yarn is withdrawn over-end, a slight increase or decrease in twist will take place, depending upon the direction of the twist in the yarn, the direction of winding on the package, and the length of the wrap on the package.5.4 When a yarn is incorporated into or removed from a more complex structure, alterations may occur as a result of the plying, untwisting, or raveling operation. For example, when determining the twist in plied yarn by the procedure for determining original twist, as the plied yarn is untwisted, a comparable amount of twist is reinserted in, or removed from, the single-yarn components. As a consequence, the single yarns have approximately the original twist prior to the plying operation but not the twist they have when they are functioning as components of the plied yarn. The latter or final twist may be estimated by adding the ply twist to (or subtracting it from) the single-yarn twist depending on the directions of the ply and singles twist. For a more precise determination, the test procedure must be modified. There are thus two different procedures for preparing specimens of the component elements of a plied or cabled yarn for twist determination. The procedure for the original twist measures the twist in a component of a complex strand after the components have been untwisted. The procedure for final twist measures the twist in a component as it lies in the complex strand. Although the original twist procedure is most often used, selection of a particular procedure will depend on the type of information needed.NOTE 3: The difference in twist between unwinding from the side and over-end is 1/πd, where d is the diameter of the package.3 Thus, for a 25 mm [1-in.] diameter package, the difference would be about 13 tpm or about 1/3 tpi.5.5 When a yarn is taken from a more complex yarn structure or from a fabric, the resultant twist should be considered only an approximation of the original value because of alterations that may have occurred as a result of the effects of unwinding, handling, and mechanical strains met in processing.5.6 The optimum amount of twist depends upon the use for which the yarn is intended. The amount of twist affects both the strength and elongation properties of the yarn with increased twist being associated with increased elongation. The relationship between twist and strength is more complex.5.6.1 In filament yarns, some twist up to 280 tpm [7 tpi] or a suitable sizing is required to facilitate textile operations. A small increase in twist results in a slight increase in strength, but a further increase results in a loss in strength. However, higher twist in such yarns may be used to subdue luster or increase elongation, or to secure other special effects, as in crepe fabrics.5.6.2 In conventional ring spun yarns a certain minimum amount of twist is necessary to bind or hold the individual fibers together to produce a useful yarn. A limited increase in twist will result in an increase in strength until the critical twist level for the particular yarn involved has been reached, but further increase in twist results in a loss in strength.5.7 The same amount of twist in yarns of different sizes (diameter) will produce yarns with different degrees of compactness, twist character, and twist angles. The twist multiplier or twist factor is approximately proportional to the tangent of the angle that the surface fibers make with the axis of the yarn. Therefore, the greater the angle, the greater the twist multiplier. A constant twist multiplier indicates comparable compactness and degree of liveliness in yarns of different sizes and conversely a difference in twist multiplier indicates a difference in compactness in yarns of the same size. Yarns intended for different uses are frequently made with different twist multipliers, for example, warp yarns and filling yarns.5.8 Different cabling processes will influence the calculation of twist from single component twist measurement. The length of cabled yarn before untwisting is used for the calculation of twist for single components using direct cabling technology. In case of 2 or more step twist technology the length of the cabled yarn after untwisting is used for calculation of the twist level in the single yarn components.5.9 Twist multiplier and twist factor are a measure of the “twist hardness” of spun yarn because they are approximately proportional to the tangent of the angle between fibers on the outer yarn surface and the axis of the spun yarn; the larger this angle, the harder the twist. Furthermore, this angle is a function of both the twist content (turns per unit length) and the number of fibers per yarn cross section (yarn number). Hence, twist content alone cannot provide a measure of the twist hardness of a yarn.1.1 This test method covers the determination of the amount and direction of twist at the completion of any stage of twisting in single (spun or filament), plied, cabled, or novelty (exclusive of long-term repeat patterns) yarns. The procedures are designed primarily for yarns in packages, but, with special precautions, they are applicable to yarns taken from fabrics. The procedure for spun yarn in 9.2 is also applicable to rovings.1.2 For plied yarns, this test method covers the determination of the twist of the plied yarns and the twist of the single yarn before plying. For cabled yarns, the test method covers the determination of the cable or hawser twist; the twist of the plied yarn after plying, but prior to the last twisting operation; and the twist of the single yarn before plying. Procedures are also included for the determination of the twists of the single and plied yarn components as they lie in the final structure. Also, directions are included for the determination of twist in plied yarn made with direct cabling technology.1.3 This test method is not intended for yarns that extend more than 5.0 % when tension is increased from 2.5 to 7.5 mN/tex [0.25 to 0.75 gf/tex]. Following the procedures of this test method for such yarns would be independent of the bias and precision determined for this test method. The report from such testing should include the tension used for this testing.1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.NOTE 1: For a more rapid but less accurate method of determining twist in single spun yarns, refer to Test Method D1422.NOTE 2: This test method has been evaluated for use in determining twist in open end yarns and is not recommended.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method is designed to rank material couples, surface treatments, and lubricants by CFT and in their resistance to adhesive wear. Since adhesive wear is a complex phenomenon and stochastic in nature, it is essential to evaluate surfaces to confirm the presence of adhesion.5.2 This test method should be considered when evaluating the impact of changes in a process or application that is prone to adhesive wear, including any combination of scoring, galling, and plowing. These modes of failure commonly occur under sliding contact, at high contact stress, and, when applicable, at lubricant starvation.5.3 The TCT is often used to evaluate the ability of material couples, surface treatments, coatings, and lubricants to prevent or reduce adhesive wear in metalworking operations including deep drawing, extrusion, and pipe bending. Other applications in which the test may be effective are loader bucket bushings, gear teeth at startup, and low-clearance pumps.5.4 This test method is best used as a comparative screening tool. The ranking of performance produced by the TCT correlates well with the ranking in many applications.3 However, since the test is a bench test and not directly reproducing any specific application, TCT results should be only used as an indicator of the tendency for adhesive wear to occur. TCT is a useful screening test for comparing the effectiveness of material couples, surface treatments, coatings, and lubricant formulations before process testing and field trials.1.1 This test method covers laboratory procedures for determining the coefficient of friction (COF) and resistance of materials to adhesion under flat sliding using the twist compression test (TCT). This test method ranks material couples, surface treatments, coatings, and lubricant combinations by COF and their resistance to adhesion.1.2 The time until adhesion for the materials under the test conditions are reported and used to quantify the tribocouple’s adhesion resistance and susceptibility to galling or scuffing. Systems of higher adhesion resistance will give longer time until failure.1.3 The coefficient of friction values averaged between the test reaching full test pressure and the time of the onset of adhesion or the end of tests run for a predetermined time period are recorded. Systems are ranked by their average coefficients of friction before adhesion occurs.1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard except psi and pounds in Table 1.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

A2.4 A2.4.1 This test method describes the testing procedure that shall be used to qualify material for use in ASTM F3043 bolts made of any steel composition permitted by this specification. The test method measures the susceptibility of the material to the influence of an externally applied potential (see A2.7.2.3.2) by testing for the threshold of embrittlement in a salt solution environment.AbstractThis specification establishes the basic requirements for one style of heat treated, alloy steel, tension control bolt-nut-washer assemblies, also known as "sets," having a tensile strength of 200 to 215 ksi. These assemblies are intended for use in structural connections in the following environmental conditions: interiors, normally dry, including interiors where structural steel is embedded in concrete, encased in masonry or protected by membrane or noncorrosive contact type fireproofing; and interiors and exteriors, normally dry, under roof, where the installed assemblies are soundly protected by a shop-applied or field-applied coating to the structural steel system.The fastener assemblies are not intended for use in structural connections in the following environments, with or without protection by a shop-applied or field-applied coating to the structural steel system: exteriors not under roof; chemical environments in which strong concentrations of highly corrosive gases, fumes, or chemicals, either in solution or as concentrated liquids or solids, contact the fasteners or their protective coating; heavy industrial environments severe enough to be classified as a chemical environment; condensation and high humidity environments maintaining almost continuous condensation, including submerged in water and soil; and cathodically protected environments, in which current is applied to the structural steel system by the sacrificial anode method or the DC power method. This specification covers materials and manufacture, chemical composition, mechanical property, assembly lot tension test, carburization/decarburization of bolts, and magnetic particle inspection for tension control bolt longitudinal discontinuities and transverse cracks.1.1 This specification covers one style of heat treated, alloy steel, tension control bolt-nut-washer assemblies, also referred to as “sets,” having a tensile strength of 200 to 215 ksi. These assemblies are capable of developing a minimum predetermined tension when installed by applying torque to the nut, while at the same time applying a counter torque to separate the spline end from the body of the bolt using an appropriate spline drive installation tool.1.2 An assembly consists of a tension control bolt with spline end, nut and washer covered by this specification.1.3 The assemblies are available with round heads described in Section 10, in sizes 1 in. to 11/4 in. inclusive.1.4 The fastener assemblies are intended for use in structural connections in the following environmental conditions:1.4.1 Interiors, normally dry, including interiors where structural steel is embedded in concrete, encased in masonry or protected by membrane or noncorrosive contact type fireproofing.1.4.2 Interiors and exteriors, normally dry, under roof, where the installed assemblies are soundly protected by a shop-applied or field-applied coating to the structural steel system.1.5 The fastener assemblies are not intended for use in structural connections in the following environments, with or without protection by a shop-applied or field-applied coating to the structural steel system:1.5.1 Exteriors not under roof.1.5.2 Chemical environments in which strong concentrations of highly corrosive gases, fumes, or chemicals, either in solution or as concentrated liquids or solids, contact the fasteners or their protective coating.1.5.3 Heavy industrial environments severe enough to be classified as a chemical environment as described in 1.5.2.1.5.4 Condensation and high humidity environments maintaining almost continuous condensation, including submerged in water and soil.1.5.5 Cathodically protected environments, in which current is applied to the structural steel system by the sacrificial anode method or the DC power method.1.6 Units—The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.1.7 The following precautionary statement pertains only to the test method portions, Section 13, Section 14 and Annex A2 of this Specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 646元 / 折扣价： 550 元 加购物车

AbstractFormerly under the jurisdiction of Committee F16 on Fasteners,this specification was withdrawn in May 2016 and replaced by Specification for High Strength Structural Bolts, Steeland Alloy Steel, Heat Treated, 120 ksi (830 MPa) and 150 ksi (1040MPa) Minimum Tensile Strength, Inch and Metric Dimensions. Specification supersedes and replaces specifications; A325, A325M, A490, A490M, F1852 and F2280. The unified Specification corrects known inconsistencies in the original documents and the combination will assure that requirements of the products covered under the original standards stay aligned. For referenced ASTM standards, visit the ASTM website, www.astm.org,or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’sDocument Summary page on ASTM website.

定价： 0元 / 折扣价： 0 元