紧固件螺纹电镀后检验标准
电镀件通用检验标准
电镀件通用检验标准
1 范围
本标准规定了电镀件的检验内容及检验方法，适用于公司来料、半成品的检查。
2 引用标准
GB/T 2828-2003 中华人民共和国国家标准（适用于产品逐批检查）。
3 定义
3.1 A 面：指电镀件正面 . （在使用过程中能直接看到的表面）
3.2 B 面：指电镀件四侧边。
（需将电镀件偏转45~90 °才能看到的四周边）3.3 软划痕：没有深度的划痕。
（无手感）
3.4 硬划痕：硬物摩擦造成的划痕或有深度的划痕。
3.5 批锋：由于注塑等原因造成塑胶边缘突起。
3.6 麻点：由于电镀环境不干净而导致有点状或线状物覆盖于产品表面的缺陷。
3.7 凸点：由于有灰尘造成电镀表面凸点状缺陷。
3.8 沙眼：由于模具压伤后留下的印痕。
4 要求
4 ． 1 检验步骤：
包装检验信赖度测试试装检验尺寸检验外观检验
4 ． 2 检验条件
4.2.1 光源 : 两支 40W 日光灯照射下距物件 1.2 ～ 1.5 米
4.2.2 目视距离:35 ± 5cm
4.2.3 目视角度：检测面与人眼方向成45° ～90°
4.2.4 目视时间 :5 ～ 10S
4 ． 3 检验仪器和工具
4.3.1 游标卡尺 [ 准确度： 0.02mm ] 4.3.2 标准菲林
4.3.3 普通刀片 [ 有保护手柄 ]
4.3.4 塞尺
4.3.5 配套卡机面、底壳 [ 工程提供 ] 4.3.6 3M 胶纸
4.3.7 RCA 耐磨测试仪
4 ． 4 检验细则
4.4.1 检验项目。
ASTM F 1941M-2005螺纹紧固件上电镀覆层的标准
Designation:F1941M–05METRICStandard Specification forElectrodeposited Coatings on Threaded Fasteners[Metric]1 This standard is issued under thefixed designation F1941M;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis specification covers the coating of steel metric screw threaded fasteners by electrodeposition. The properties of the coatings shall conform to the ASTM standards for the individualfinishes listed. Coating thickness values are based on the tolerances for M series metric threads having the following tolerance positions:6g and4g6g for external threads,and6H for internal threads.The coating must not cause the basic thread size to be transgressed by either the internal or external threads.The method of designating coated threads shall comply with ASME B1.13M.With normal methods for depositing metallic coatings from aqueous solutions,there is a risk of delayed failure due to hydrogen embrittlement for case hardened fasteners and fasteners having a hardness40HRC or above.Although this risk can be managed by selecting raw materials suitable for the application of electrodeposited coatings and by using modern methods of surface treatment and post heat-treatment(baking),the risk of hydrogen embrittlement cannot be completely eliminated. Therefore,the application of a metallic coating by electrodeposition is not recommended for such fasteners.1.Scope1.1This specification covers application,performance and dimensional requirements for electrodeposited coatings on threaded fasteners with metric screw threads.It specifies coating thickness,supplementary chromatefinishes,corrosion resistance,precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for high-strength and surface-hardened fasteners.It also highlights the differences between barrel and rack plating and makes recom-mendations as to the applicability of each process.1.2The following precautionary statement pertains to the test method portion only,Section9,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 limita-tions prior to use.2.Referenced Documents2.1ASTM Standards:2B117Practice for Operating Salt Spray(Fog)Apparatus B487Test Method for Measurement of Metal and Oxide Coating Thickness by Miocroscopical Examination of a Cross SectionB499Test Method for Measurement of Coating Thickness by the Magnetic Method:Nonmagnetic Coatings on Mag-netic Basis MetalsB504Test Method for Measurement of Thickness of Me-tallic Coatings by the Coulometric MethodB567Test Method for Measurement of Coating Thickness by the Beta Backscatter MethodB568Test Method for Measurement of Coating Thickness by X-Ray SpectrometryB659Guide for Measuring Thickness of Metallic and Inorganic Coatings1This specification is under the jurisdiction of ASTM Committee F16onFasteners and is the direct responsibility of Subcommittee F16.03on Coatings on Fasteners.Current edition approved May1,2005.Published May2005.Originally approved st previous edition approved in2000as F1941M–00.2For referenced ASTM standards,visit the ASTM website,,or contact ASTM Customer Service at service@.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page on the ASTM website.1Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.E 376Practice for Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic)Exami-nation MethodsF 606Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners,Washers,and RivetsF 1470Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance InspectionF 1624Test Method for Measurement of Hydrogen Em-brittlement Threshold in Steel by the Incremental Step Loading TechniqueF 1940Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners2.2ASME Standard:3B1.13M Metric Screw Threads -M Profile 2.3National Aerospace Standard (AIA):4NASM-1312-5Fast Test Method -Method 5:Stress Dura-bility2.4IFI Standard:5IFI-142Hydrogen Embrittlement Risk Management 3.Terminology 3.1Definitions:3.1.1local thickness —mean of the thickness measurements,of which a specified number is made within a reference area.3.1.2minimum local thickness —lowest local thickness value on the significant surface of a single article.3.1.3reference area —area within which a specified number of single measurements are required to be made.3.1.4significant surface —significant surfaces are areas where the minimum thickness to be met shall be designated on the applicable drawing or by the provision of a suitably marked sample.However,if not designated,significant surfaces shall be defined as those normally visible,directly or by reflection,which are essential to the appearance or serviceability of the fastener when assembled in normal position,or which can be the source of corrosion products that deface visible surfaces on the assembled fastener.Figs.1and 2illustrate significant surfaces on standard externally threaded and internally threaded fasteners.4.Classification4.1Coating Material —The coating material shall be se-lected and designated in accordance with Table 1.4.2Coating Thickness —The coating thickness shall be selected and designated in accordance with Table 2.4.3Chromate Finish —The chromate finish shall be selected and designated in accordance with Table 3.5.Ordering Information for Electroplating5.1When ordering threaded fasteners to be coated by electrodeposition in accordance with this specification,the following information shall be supplied to the electroplater:5.1.1The desired coating,coating thickness and the chro-mate finish,or the classification codes as specified in Tables 1-3.(For example,Fe/Zn 5C denotes yellow zinc plated with a minimum thickness of 5µm on significant surfaces.)5.1.2The identification of significant surfaces (optional).5.1.3The requirement,if any,for stress relief before elec-troplating,in which case the stress-relief conditions must be specified.5.1.4The requirements,if any,for hydrogen embrittlement relief by heat treatment (baking)stating the tensile strength or surface hardness of the fasteners and/or baking time and temperature.N OTE 1—Fasteners with a specified maximum hardness of 34HRC and below have a very low susceptibility to hydrogen embrittlement and do not require baking.3Available from American Society of Mechanical Engineers (ASME),345E.47th Street,New York,NY 10017.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,Section D,700Robbins Ave.,Philadelphia,PA 19111-5098.5Available from Industrial Fasteners Institute (IFI),1717East 9th Street,Suite 1105,Cleveland,OH44114–2879.N OTE 1—Black dot (•)indicates test surface.FIG.1Significant surfaces on Externally ThreadedFastenersN OTE 1—Black dot (•)indicates test surface.FIG.2Significant surfaces on Internally Threaded FastenersTABLE 1Designation of Common Coating MaterialsCoating DesignationCoating Type Fe/Zn Zinc Fe/Cd Cadmium Fe/Zn-Co Zinc Cobalt Alloy Fe/Zn-Ni Zinc Nickel Alloy Fe/Zn-FeZinc Iron AlloyTABLE 2Designation of Coating ThicknessN OTE 1—The conversion factor from microns to inch is 3.94310–5(for example,5µm =0.0002in.).Thickness DesignationMinimum Thickness µm3355881212F 1941M –055.1.5The requirements,if any,for the type of electroplating process (barrel-plating or rack-plating).See Section 10and Appendix X1.5.1.6The designation of coated thread class shall comply with ASME B1.13M.6.Requirements6.1Coating Requirements —The electrodeposited coating as ordered shall cover all surfaces and shall meet the following requirements:6.1.1The coating metal deposit shall be bright or semi-bright unless otherwise specified by the purchaser,smooth,fine grained,adherent and uniform in appearance.6.1.2The coating shall be free of blisters,pits,nodules,roughness,cracks,unplated areas,and other defects that will affect the function of the coating.6.1.3The coating shall not be stained,discolored or exhibit any evidence of white or red corrosion products.6.1.3.1Slight discoloration that results from baking,drying,or electrode contact during rack-plating,or all of these,as well as slight staining that results from rinsing shall not be cause for rejection.6.2Corrosion Resistance —Coated fasteners,when tested by continuous exposure to neutral salt spray in accordance with 9.3,shall show neither corrosion products of coatings (white corrosion)nor basis metal corrosion products (red rust)at the end of the test period.The appearance of corrosion products visible to the unaided eye at normal reading distance shall be cause for rejection,except when present at the edges of the tested fasteners.Refer to Annex A1for neutral salt spray performance requirements for zinc,zinc alloy and cadmium coatings.6.3Thickness —The coating thickness shall comply with requirements of Table 2when measured in accordance with 9.1.6.3.1Restrictions on Coating Thickness —This specification imposes minimum local thickness requirements at significant surfaces in accordance with Table 2.Thick or thin local thickness in a location other than a significant surface shall not be a cause for rejection.However the following restrictions apply:6.3.1.1Minimum coating thickness at low current density areas,such as the center of a bolt or recesses,must be sufficient to provide for adequate chromate adhesion.6.3.1.2External Threads —Maximum coating thickness at high current density threaded tips must provide for basic (tolerance position h )GO thread gauge acceptance.Therefore,the thread after coating is subject to acceptance using a class 6hGO gauge for plated 6g class external threads and 4h6h GO gauge for plated 4g6g class external threads respectively.6.3.1.3Internal Threads —Maximum coating thickness of internal threads must provide for basic (tolerance position H )Go thread gauge acceptance.Therefore,the thread after coating is subject to acceptance using a class 6H GO gauge for 6H class internal threads.6.3.1.4Surfaces such as threads,holes,deep recesses,bases of angles,and similar areas on which the specified thickness of deposit cannot readily be controlled,are exempted from minimum thickness requirements unless they are specially designated as not being exempted.When such areas are subject to minimum thickness requirements,the purchaser and the manufacturer shall recognize the necessity for either thicker deposits on other areas or special racking.6.3.2Applicability to M Series Threads :6.3.2.1The applicability of the required coating to M series metric threads is limited by the basic deviation of the threads,and hence limited by the pitch diameter,allowance,and tolerance positions.Refer to Appendix X3as a guideline for the tolerances of the various thread sizes and classes and the coating thickness they will accommodate.6.3.2.2Because of the inherent variability in coating thick-ness by the barrel-plating process,the application of a mini-mum coating thickness of 12µm is not recommended for a standard screw thread by this method due to the fact that dimensional allowance of many metric threaded fasteners normally does not permit it.If the size of the fastener is large enough to economically use the rack-plating process,then the latter shall be used to obtain this thickness requirement.If heavier coatings are required,allowance for the deposit buildup must be made during the manufacture of fasteners.6.3.3Applicability to Wood Screws and Thread Forming Screws —Any classification code in Table 2may be applied to screws that cut or form their own threads.6.4Hydrogen Embrittlement Relief :6.4.1Requirement for Baking —Coated fasteners made from steel heat treated to a specified hardness of 40HRC or above,case-hardened steel fasteners,and fasteners with captive wash-ers made from hardened steel,shall be baked to minimize the risk of hydrogen embrittlement.Unless otherwise specified by the purchaser,baking is not mandatory for fasteners with specified maximum hardness below 40HRC.N OTE 2—With proper care many steel fasteners can be plated without baking by correlating process conditions to the susceptibility of the fastener material to hydrogen embrittlement,and by applying adequate process control procedures,such as those outlined in X4.2.Test Method F 1940is a recognized verification method for process control to minimize the risk of hydrogen embrittlement.Upon agreement between the supplier and the purchaser,this test method can be used as a basis for determining if baking should be mandated in a controlled process environment.6.4.2Baking Conditions —At the time of publication of this specification it was not considered possible to give an exact baking duration.Eight hours is considered a typical example of baking duration.However,upon agreement between the pur-chaser and the manufacturer,baking times between 2and 24h at temperatures of 175to 235°C (350to 450°F)are suitable depending on the type and size of the fastener,geometry,TABLE 3Designation of Chromate FinishDesignationType Typical AppearanceA Clear Transparent colorless with slight iridescenceB Blue-bright Transparent with a bluish tinge and slight iridescenceC Yellow Yellow iridescentD Opaque Olive green,shading to brown or bronzeE Black Black with slight iridescenceFOrganicAny of the above plus organictopcoatmechanical properties,cleaning process and cathodic effi-ciency of the electroplating process used.The baking condi-tions shall be selected based on the results of recognized embrittlement test procedures such as Test Methods F1940, F1624,F606,or NASM1312-5.6.4.2.1Bake time and temperatures may require lowering to minimize the risk of solid or liquid metal embrittlement resulting from alloy compositions such as those containing lead or from the lower melting point of cadmium320°C(610°F)in comparison to zinc419°C(786°F).6.4.2.2Fasteners must be baked within4h,preferably1h after electroplating.Baking to relieve hydrogen embrittlement must be performed prior to the application of the chromate finish because temperatures above65°C(150°F)damage the chromatefilm thereby negating its performance.6.4.3Hydrogen Embrittlement Testing—Hydrogen em-brittlement testing is mandatory for fasteners with a specified hardness of40HRC or above,unless the electroplating process has been qualified in accordance with Test Method F1940(that is,the process has been shown not to cause embrittlement for a given product or class of product).This specification does not require mandatory testing of fasteners having a specified hardness below40HRC,unless otherwise specified by the purchaser.7.Dimensional Requirements7.1Threaded components,except those with spaced and forming threads,supplied for electrodeposited coating shall comply with ASME B1.13M.Screw threads that are specifi-cally manufactured to allow the application of12µm or greater coating thickness by the barrel-plating process,must adhere to a special allowance specified by the manufacturer or in ASME B1.13M.The other dimensional characteristics shall be as specified on the applicable standard or drawing.It should be noted that modifications to the threads of a fastener could affect its properties or performance,or both.Refer to Appendix X3 for further information on effects of coating on pitch diameter, allowances and tolerances for external and internal threads.8.Sampling8.1Sampling for coating thickness,salt spray and embrittle-ment testing shall be conducted based on lot size in accordance with Guide F1470.9.Test Methods9.1Coating Thickness—Unless otherwise specified,the re-quirement to measure coating thickness is applicable to sig-nificant surfaces only.The test methods for determining the coating thickness are defined in Test Methods B487,B499, B504,B567,B568,Guide B659or Practice E376as applicable.9.2Embrittlement Test Method—The embrittlement test method shall conform to those specified in Test Method F1940 for process verification,or Test Methods F606,F1624,or NASM-1312-5for product testing.9.3Corrosion Resistance—The requirement to determine corrosion resistance is applicable to significant surfaces only. When specified in the contract or purchase order,salt spray testing shall be conducted in accordance with Practice B117. To secure uniformity of results,samples shall be aged at room temperature for24h before being subjected to the salt spray test.10.Electroplating Processes10.1Two electroplating processes are most commonly used to apply a metallic coating by electrodeposition on threaded fasteners:barrel-plating and rack-plating.When threadfit or thread integrity,or both,is a concern for externally threaded fasteners,rack-plating is preferable to barrel-plating.Refer to Appendix X1.11.Keywords11.1chromatefinish;electrodeposited coating;fasteners; hydrogen embrittlement relief;hydrogen embrittlement test-ing;surfacetreatmentANNEX(Mandatory Information)A1.NEUTRAL SALT SPRAY PERFORMANCETABLE A1.1Classification Code and Neutral Salt Spray Corrosion Protection Performance of Zinc and Cadmium CoatingsClassification Code Minimum Coating Thickness(µm)Chromate Finish DesignationFirst Appearance of White Corrosion Product,(hour)First Appearance of Red Rust Cadmium,(hour)First Appearance of Red Rust Zinc,(hour)Fe/Zn or Fe/Cd 3A 3AA 32412Fe/Zn or Fe/Cd 3B B 62412Fe/Zn or Fe/Cd 3C C 243624Fe/Zn or Fe/Cd 3D D 243624Fe/Zn or Fe/Cd 5A 5A 64824Fe/Zn or Fe/Cd 5B B 127236Fe/Zn or Fe/Cd 5C C 4812072Fe/Zn or Fe/Cd 5D D 7216896Fe/Zn or Fe/Cd 5E E 1272Fe/Zn or Fe/Cd 8A 8A 69648Fe/Zn or Fe/Cd 8B B 2412072Fe/Zn or Fe/Cd 8C C 72168120Fe/Zn or Fe/Cd 8D D 96192144Fe/Zn or Fe/Cd 8E E 2412072Fe/Zn or Fe/Cd 12A 12A 614472Fe/Zn or Fe/Cd 12B B 2419296Fe/Zn or Fe/Cd 12C C 72240144Fe/Zn or Fe/Cd 12D D 96264168Fe/ZnorFe/Cd12BkE2419296ALow coating thickness impairs chromate adhesion and performance.TABLE A1.2Classification Code and Neutral Salt Spray Corrosion Protection Performance of Zinc-Cobalt CoatingsClassification CodeMinimum Coating Thickness (µm)Chromate Finish DesignationFirstAppearance of Zinc Alloy Corrosion Product (hour)FirstAppearance of Red Rust (hour)Fe/Zn-Co 5C 5C 96240Fe/Zn-Co 5D D 96240Fe/Zn-Co 5E E 100240Fe/Zn-Co 5F F 196340Fe/Zn-Co 8C 8C 96240Fe/Zn-Co 8D D 96240Fe/Zn-Co 8E E 100240Fe/Zn-Co 8F F 200340Fe/Zn-Co 12B 12B 12240Fe/Zn-Co 12C C 96400Fe/Zn-Co 12D D 96400Fe/Zn-Co 12E E 100400Fe/Zn-Co12FF196500APPENDIXES(Nonmandatory Information)X1.STANDARD ELECTRODEPOSITION PROCESSESX1.1Barrel-Plating Process —The preparation and metallic coating of threaded fasteners is usually accomplished by the barrel-plating process.In this process,quantities of an item are placed within a containment vessel,called a barrel.The barrel is designed to move the group of items,together,through each of the process steps,allowing ready ingress and egress of processing solutions and rinses.As the barrel is moved through the process steps,it is also rotated such that the individual items are constantly cascading over one another.This can damage the external threads of fasteners.The effect of thread damage is worse on heavy fine threaded fasteners than on light coarse threaded fasteners.In some of the process steps,notably the electrocleaning and electroplating steps,an electric current is applied to the group of items.The cascading action randomly exposes the surface of each individual piece to the process electrodes while also maintaining electrical continuity between all the parts.The local coating thickness on a part is a result of the electrical current density at that location.Therefore,the coating thickness on an individual screw or bolt tends to be greatest at the extremities (head and threaded tip).The extremi-ties being the high current density areas receive the greatest coating thickness.In contrast,the center or recesses such as the bottom of the threads,which are the low current density areas,receive the lowest coating thickness.This phenomenon is accentuated with increasing length and decreasing diameter of the screw or bolt.The extremity-to-center coating thickness ratio increases with increasing length and decreasing diameter,but is also a function of process parameters such as plating solution chemistry and efficiency,anodic/cathodic efficiency,average current density and plating time.TABLE A1.3Classification Code and Neutral Salt Spray Corrosion Protection Performance of Zinc-Nickel CoatingsClassification CodeMinimum Coating Thickness (µm)Chromate Finish DesignationFirstAppearance of Zinc Alloy Corrosion Product (hour)FirstAppearance of Red Rust (hour)Fe/Zn-Ni 5B 5B 20150Fe/Zn-Ni 5C C 120500Fe/Zn-Ni 5D D 180750Fe/Zn-Ni 5E E 100500Fe/Zn-Ni 5B/F B/F 150300Fe/Zn-Ni 5C/F C/F 240620Fe/Zn-Ni 5D/F D/F 3001000Fe/Zn-Ni 5E/F E/F 220620Fe/Zn-Ni 8B 8B 20240Fe/Zn-Ni 8C C 120720Fe/Zn-Ni 8D D 180960Fe/Zn-Ni 8E E 100720Fe/Zn-Ni 8B/F B/F 150400Fe/Zn-Ni 8C/F C/F 240840Fe/Zn-Ni 8D/F D/F 3001200Fe/Zn-Ni 8E/F E/F 220840Fe/Zn-Ni 12B 12B 20500Fe/Zn-Ni 12C C 120960Fe/Zn-Ni 12D D 1801000Fe/Zn-Ni 12E E 100960Fe/Zn-Ni 12B/F B/F 150620Fe/Zn-Ni 12C/F C/F 2401080Fe/Zn-Ni 12D/F D/F 3001500Fe/Zn-Ni12E/FE/F2201080TABLE A1.4Classification Code and Neutral Salt Spray Corrosion Protection Performance of Zinc-Iron CoatingsClassification CodeMinimum Coating Thickness (µm)Chromate Finish DesignationFirstAppearance of Zinc Alloy Corrosion Product (hour)FirstAppearance of Red Rust (hour)Fe/Zn-Co 5E 5E 144312Fe/Zn-Co 8E 8E 144312Fe/Zn-Co 12E12E144480X1.2Rack-Plating Process —The preparation and metallic coating of threaded fasteners can be accomplished by the rack-plating process,particularly on large size fasteners where thread fit and/or damage is a concern,or for smaller size fasteners when it is economically feasible.In this process,quantities of an item are placed on a support,called a rack.The rack is designed to move the group of items,together,through each of the process steps,allowing ready ingress and egress of processing solutions and rinses.In some of the process steps,notably the electrocleaning and electroplating steps,an electric current is applied to the group of items.The electrical continuity is maintained between the parts by the rack itself.The average current density is usually low enough such that the extremity-to-center coating thickness ratio is much lower than with barrel-plating.The external thread damage is also mini-mized in comparison to barrel-plating due to the absence of tumbling.X2.GUIDELINES FOR CHOOSING BETWEEN BARREL-PLATING AND RACK-PLATINGX2.1Table X2.1indicates the recommended electroplating process for each size of externally threaded metric fasteners for all thickness classes in Table 2.For internally threaded fasteners barrel-plating is generally suitable.X3.COATING ACCOMMODATION TOLERANCES FOR EXTERNALLY AND INTERNALLY THREADED FASTENERSX3.1Short screws and bolts are those with a length-to-diameter ratio equal to or less than 5.Long screws and bolts have a length-to-diameter ratio greater than 5but less than 10.Special processing is normally required for bolts with a ratio greater than 10in order to minimize the extremity-to-center thickness ratio.X3.2This specification does not impose maximum thick-ness values on high current density areas,where the coating thickness tends to be the greatest.On an externally threaded fastener this occurs at the threaded tip.Measuring coating thickness on the threaded portion of a fastener is possible but impractical for in-process quality control verification.For this reason the control mechanism specified in this document is by means of GO thread gauges.Nevertheless Table X3.1,which is supplied as an informative guideline,illustrates the maximum coating thickness permitted by the allowance for tolerance classes 6g and 4g6g.N OTE X3.1—The following information is based on ASME B1.13M .That standard should be consulted for more detailed information.X3.3Size limits for standard tolerance classes 6g and 4g6g apply prior to coating.The external thread allowance may thusbe used to accommodate the coating thickness on threaded fasteners,provided the maximum coating thickness is no more than 1⁄4of the allowance (see Fig.X3.1).Thus,threads after coating are subject to acceptance using a class 6h GO gauge for plated 6g class external threads and 4h6h GO gauge for plated 4g6g class external threads respectively.Class 6g and 4g6g shall be used as respective NOT-GO gauges.X3.4In certain cases size limits must be adjusted,within the tolerances,prior to coating,in order to insure proper thread fit.This applies to the following cases:X3.4.1Standard internal threads,because they provide no allowance for coating thickness.X3.4.2Where the external thread has no allowance,such as in class h external threads.X3.4.3Where allowance must be maintained after coating for trouble free thread fit.X3.5Table X3.1provides maximum coating thickness values based only on the allowance for external thread toler-ance classes 6g and 4g6g.It assumes that the external thread pitch diameter is at the maximum and that the internal thread pitch diameter is at the minimum of the tolerance.TABLE X2.1Recommended Electroplating Process for Each Size of Externally Threaded Metric FastenersN OTE 1—Barrel-plating process (B)and rack-plating process (R).Diameter (D),(in.)Length (L)L #5D5D <L #10D10D <L #20D20D <L #30DL >30D M1.6-M4B B B B R M5-M6B B B R R M8-M10B B B R R M12B B R R R M14B B R R R M16B B R R R M20B R R R R M24R R R R R M30-M100RRRRRTABLE X3.1Coating Accommodation Tolerances for ExternallyThreaded Class 6g and 4g6g Metric FastenersThread Pitch,mm Diameter,(in.)Pitch Diameter Allowance for 6g and 6g4g Tolerance Positions,(µm)Maximum Allowable Coating Thickness on Threaded Tip(µm)0.35M1.6–1940.4M2–1940.45M2.5–2050.5M3–2050.6M3.5–2150.7M4–2250.8M5–2461M6–2661.25M8–2871.5M10–3281.75M12–3482M14,M16–3892.5M20–42103M24–48123.5M30–53134M36–60154.5M42–63155M48–71175.5M56–75186M64,M72,M80,M90,M100–8020FIG.X3.1Metric Tolerance System for ScrewThreadsX4.APPLICATION REQUIREMENTSX4.1Cleaning of Basis Metal—Thorough cleaning of the basis metal is essential in order to ensure satisfactory adhesion, appearance and corrosion resistance of the coating.X4.2Hydrogen Embrittlement Risk Management:X4.2.1Process Considerations—The following are some general recommendations for managing the risk of hydrogen embrittlement.For more detailed information refer to IFI-142. X4.2.1.1Clean the fasteners in non-cathodic alkaline solu-tions and in inhibited acid solutions.X4.2.1.2Use abrasive cleaners for fasteners having a hard-ness of40HRC or above and case hardened fasteners.X4.2.1.3Manage anode/cathode surface area and efficiency, resulting in proper control of applied current densities.High current densities increase hydrogen charging.X4.2.1.4Use high efficiency plating processes such as zinc chloride or acid cadmiumX4.2.1.5Control the plating bath temperature to minimize the use of brighteners.X4.2.1.6Select raw materials with a low susceptibility to hydrogen embrittlement by controlling steel chemistry,micro-structure and mechanical properties.X4.2.2Process Control Verification—Test Method F1940 should be used as a test method for process control to minimize the risk of hydrogen embrittlement.Periodic inspections should be conducted according to a specified test plan.The test plan should be designed based upon the specific characteristics of a process,and upon agreement between the purchaser and the manufacturer.The testing frequency should initially estab-lish and subsequently verify over time,the ability of a process to produce parts that do not have the potential for hydrogen embrittlement.PARISON OF THE REQUIREMENTS OF SPECIFICATION F1941M–00VERSUS ISO4042–99X5.1Table X5.1provides the main differences that exist between Specification F1941M–00versus ISO4042–99.In many cases,both standards do not use the same numbering system to address a similar provision.If needed,the reader must refer to the related paragraph(s)of each standard in its entirety to fully appreciate thecomparison.。
紧固件检验规范标准
紧固件检验规文件编号：版次：编制：审核：批准：受控状态：发布日期： 2011 年 7月 30 日实施日期： 2011 年 7月 30 日紧固件检验规1 目的为了确保本公司采购的紧固件符合技术设计的要求，特制订本检验规，采购人员与检验人员需依此检验规进行采购和验收。
2 围本检验规规定了本公司采购的各种标准紧固件（包括螺钉、螺栓、螺母、垫圈、自攻螺钉等）的技术要求、测试方法、验收规则。
3 职责检验员：负责依据检验规及相关产品规格资料执行各项检验。
采购人员：负责依本规的质量要求进行产品的采购。
质量部经理：负责审批相关检验记录表，协调处理质量异常问题。
4 工作程序4.1 操作者资格经公司培训、考核合格，取得质量检验员任职资格，了解紧固件的相关术语及要求。
4.2 检测设备及工具游标卡尺（0.02mm） 1六角搬手 1套4.3 测试条件典型环境温度：；20℃—30℃典型环境湿度：30%—60%4.4 检验项目、技术要求及测试方法4.4.1 质量说明文件目测法检查，要求送检产品应附有相应的“产品合格证”或“检测记录”。
“检测记录”中测试数据应在其相应规允许围并结论合格。
4.4.2产品型号、数量目测法检查，要求根据装相单中填写的规格型号和数量描述情况查验实物应与送检单描述一致。
4.4.3产品包装目测法检查，要求产品、外包装完好无破损、无碰撞或淋雨现象，标识清晰。
4.4.4外观、性能技术要求、缺陷分类及测试方法4.4.4.1外观表面质量、缺陷分类及测试方法外观表面质量、缺陷分类及测试方法见表1。
表1 外观表面质量、缺陷分类及测试方法序号检验项目技术要求测试方法及工具缺陷分类MAJ MIN1 包装不允许混入其它不同品种、规格或半成品目测法√2 镀层有镀层产品镀层应完整、无漏镀、浮锈√3 表面产品应清洁，无油污、金属屑、毛刺√无烂牙、螺纹异常√表面无裂缝、爆裂、在拐角上不允许有皱纹√不影响使用的凹痕（凹痕深度不得超过0.02d，最大值为0.25mm）√4.4.4.2技术指标要求、缺陷分类及测试方法4.4.4.2.1螺栓的技术要求、缺陷分类及测试方法螺栓的技术要求、缺陷分类及测试方法见表2，外形图见图1。
紧固件检验程序规则
第七章验收检查7.1 概述由于紧固件的生产批量大，检验项目多，不可能进行百分之百的全数检验，否则要花费很高的检验费用，尤其是破坏性试验，要实施全数检验是根本不可能的。
由于通过小的样本n来判定批量N的产品合格与否，就不可避免地存在两个风险（误判），即生产者风险α和用户风险β，n越小，风险越大，加大样本大小，可以降低风险，然而，从经济性角度来衡量，n越小检验成本也就越小。
紧固件验收检查是一项极为重要的基础标准，是供需双方对交付验收的紧固件产品批是接收或拒收的依据。
国际标准化组织于上世纪80年代初着手制定《紧固件验收检验》标准，现行标准ISO 3269：2000（GB/T 90.1—2002，idt等同采用）。
随着贸易的发展和用户对紧固件质量要求的不断提高，各国的紧固件验收检查标准也在不断的提高和完善。
目前，中国、日本、意大利、澳大利亚和英国等已等效或等同采用ISO 3269制定了国家标准。
美国有自已的紧固件质量检验标准。
7.2 国际紧固件验收检查标准7.2.1 适用范围在订货时，未与紧固件供方协议采用其他验收检查程序时，需方必须遵循本标准规定的验收程序，以确定一批紧固件的验收或拒收。
本标准适用于螺栓、螺钉、螺柱、螺母、销、垫圈、盲铆钉和其他相关的紧固件。
本标准不适用于高速机械装配，以及特殊工程监理的紧固件产品的验收检查。
供方可向其他供货者购买附件、半成品和进行工艺外协作、加工，成品的最终提供者应对紧固件的最终产品质量完全负责。
本标准适用于交货时的紧固件，而不适用接收后的紧固件再加工、处理（镀层）的检验。
7.2.2 验收检查的基本规则7.2.2.1 本抽样方案的生产者风险应不大于5%。
7.2.2.2 在验收过程中应强调，着重考虑产品是否符合预期的功能。
7.2.2.3 对已拒收的紧固件，必须经修整或分类后，才能复检。
7.2.2.4 验收检查中，如有争议应采用直接测量进行判定，但对螺纹检查仍应以螺纹量规的检查结果作为验收依据。
GBT 52673-2004紧固件 热浸镀锌层
2)．不同标准螺纹尺寸調正方法。
（一）、按英制或美标订货时，通常的做法是采用美国的方法， 即第三种方法。
按ASTM A153、ASME A307或ASME A563标准 的规定，即镀前外螺纹中径不改变（美制2A、英制F、N）， 镀后内螺纹要加大攻丝（工艺上有的是镀前攻2B、N内螺纹， 镀后再用加大了的丝锥回攻），
6、机械性能及组装件的强度
由于加大内螺纹螺母攻丝尺寸或小外螺纹另件螺纹尺寸，
即使可达到机械性能的要求，但与规定相配的元件组装时， 也可能达不到预期的组装件强度。
但为不降低组装件强度有两种方案可选择： • 用较高性能等级的螺母与螺栓和螺钉相配，如8.8级的 螺栓或螺钉配10级螺母等。 • 用相同性能等级，但以2型代替1型的螺母与螺栓或螺钉 相配。
7、性能等级的标志及产品标记
A）. 加大攻丝尺寸的螺母应紧跟性能等级标志之后 标志字母 Z（6AZ级）或X（6AX级）
B）.减小螺纹尺寸的螺栓和螺钉应紧跟性能 标志之后标志字母 U。 Ｃ）.热浸镀锌使用的代号为：tZn。 出囗紧固件的热镀锌用HGD。 等级
7、性能等级的标志及产品标记
示例1：
1型六角螺母GB/T 6170 M12、性能等级为8级、 加大攻丝尺寸6AZ螺纹热浸镀锌螺母的标记：
GB/T 5267.3－2004 紧固件 热浸镀锌层
（国家标准报批稿） 整理的资料.版权属于原创人员
前
言
紧固件热浸镀锌与相关的检验标准主要有： 国际 ISO 10684：2004 《紧固件－－热浸镀锌层》 美国ASTM A153-2000 《铁钢紧固件热镀锌》 德国DIN 267／10-1988 《紧固件热镀锌技术条件》
一、工艺和特点
螺栓检验标准
目测、漆膜应光滑、色泽均匀，锐边倒钝。
i、外观质量不合格则判定不合格
第5步
外观
测厚仪
10、螺牙需加工完整，不得出现螺牙残缺和加工不完整j、有残余金属屑判定不合格
现象。
11、六角头需加工完整，六角内不应有残余金属屑。
游标卡尺12、依据抽样方案抽取产品并按照GB/T3103.1-2002紧k、依据标准要求逐项检验，尺寸不符
q、表面处理工艺化学氧化，点滴液为
3%中性硫酸铜溶液，点滴在试样表面出
现玫瑰红色斑点的时间大于30秒为合
16、依据抽样方案抽取产品并按照GB/T 10125-2002规格；
盐雾试验定的条件下进行试验；
r、表面处理工艺（锰盐磷化或锌盐磷
定期抽检
化），点滴液为0.2mol/L的硫酸铜40
毫升、100g/L的氯化钠20毫升和0.1
检验员确认/日期
螺栓检验标准
编号：
检验项目检测设备
资料审查
详细操作方法及内容
标准要求、注意事项
备注
操作步骤
第1步
a、材质单格式及必填内容应符合采购
物流事业部规定的《原材料材质单的规
定》
供应商需提供资料：
1、《原材料材质单》或《质量证明书》(样品确定、定期
检验)；
b、《供应商自检报告》应包括本检验标
准的9-18项内容。
中不变形、撞伤、损坏等。能够
防止受潮和混入杂质。
包装箱外表应注明制造
厂名，产品名称和编码，
产品数量，制造或者出
厂日期，产品质量标记
包装方式
包装标识
GB/T 3098.1-2000紧固件机械性能螺栓、螺钉和螺柱
电镀件检验标准
电镀件检验标准电镀件是一种表面处理工艺，通过在金属表面镀上一层金属或非金属的薄层，以改善金属的性能和外观。
电镀件广泛应用于汽车、家电、电子产品等领域，因此其质量的稳定性和可靠性对产品的整体质量至关重要。
为了确保电镀件的质量，制定了一系列的检验标准，以便对电镀件进行全面、严格的检验。
本文将介绍电镀件的检验标准及其相关内容。
首先，电镀件的检验标准主要包括外观检验、厚度检验、粘附力检验、耐蚀性检验等内容。
外观检验主要是对电镀件表面的光泽、平整度、气泡、皱纹、斑点等进行检查，以确保其外观质量符合要求。
厚度检验是对电镀层的厚度进行测量，以确保其厚度符合设计要求。
粘附力检验是对电镀层与基材之间的结合力进行测试，以确保其粘附力符合标准。
耐蚀性检验是对电镀件在不同腐蚀介质中的耐蚀性进行测试，以确保其耐蚀性符合要求。
其次，电镀件的检验标准还包括检验方法、检验设备、检验规范等内容。
检验方法是指对电镀件进行检验的具体操作步骤和方法，包括外观检验的目视检查、厚度检验的仪器测量、粘附力检验的划格法、耐蚀性检验的盐雾试验等。
检验设备是指用于对电镀件进行检验的各种仪器设备，包括外观检验的显微镜、厚度检验的厚度计、粘附力检验的划格仪、耐蚀性检验的盐雾试验箱等。
检验规范是指对电镀件进行检验时应遵循的标准和规范，包括国家标准、行业标准、企业标准等。
最后，电镀件的检验标准对于保证产品质量、提高产品竞争力具有重要意义。
严格按照检验标准对电镀件进行检验，可以有效地发现和排除产品质量问题，提高产品的合格率和一致性，降低产品的不合格率和成本，提高产品的市场竞争力和用户满意度。
因此，制定和执行严格的电镀件检验标准，对于保障产品质量和企业利益具有重要意义。
综上所述，电镀件的检验标准是保证产品质量、提高产品竞争力的重要手段，其内容涵盖外观检验、厚度检验、粘附力检验、耐蚀性检验等方面，包括检验方法、检验设备、检验规范等内容。
严格执行检验标准，对于提高产品的合格率和一致性，降低产品的不合格率和成本，提高产品的市场竞争力和用户满意度具有重要意义。
紧固件来料抽样检验规范
紧固件来料抽样检验规范（ISO9001-2015）1.0目的为了规范紧固件来料检验及抽样计划，并促进来料质量的提高，特制定该检验规范。
2.0适用范围适用于公司IQC对紧固件来料的检验。
3.0规范性引用文件（版本以公司最新发布版本为准）GB/T 2828.1-2013 计数抽样检验程序第1部分GB/T 197-2003 普通螺纹公差4.0通用验收标准和基本规则4.1 如无特殊说明（如不锈钢、镀镍等），国标紧固件按照镀彩锌检验。
4.2 公差等级根据图纸要求进行检验，图纸尚未规定或无图纸的，按照下面要求执行：对外螺纹规定三种公差带位置：g、f、e；对内螺纹规定二种公差带位置：H、G；镀后螺纹的实际轮廓上的任何点均不应超越H、h确定的最大实体牙型；电镀螺纹紧固件必须同时满足镀层厚度和旋合性两方面的要求。
5.0检验内容检验项目检验方式检验方法、标准检验手段备注包装GB2828.1-2003IL=IAQL=1.0外包装实行全检（0,1）1、内、外包装均要求防潮且无破损。
2、内包装应有厂家标识，内容包括但不限于：物料名称、规格型号、数量、批次号。
目测外观GB2828.1-2003IL=IAQL=1.01、表面镀层致密、均匀一致，无麻点、黑点、疙瘩、起泡、脱落等缺陷。
电镀层应有光泽。
2、紧固件的螺纹牙型不能有磕碰、损伤现象，其余部分的损伤应不影响产品的使用性。
3、紧固件不能带有毛刺、利角。
目测尺寸螺纹尺寸1～100件抽 2PCS（0，1）＞100件抽4PCS（0，1）应满足通规通，止规止（检验时可使用相对应的螺钉、螺母进行适配）。
螺纹通止规其它尺寸1～100件抽 2PCS（0，1）＞100件抽4PCS（0，1）根据图纸进行检验，没有图纸的紧固件螺纹大小径、有效长度、头部直径、槽型符合国家标准要求。
卡尺镀层耐蚀性原则上1次/每厂家/每月，平时可根据需求随时抽测按照GB/T 10125-1997《人造气氛腐蚀试验盐雾试验》，采用中性（NSS）盐雾试验进行连续喷雾测试。
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紧固件螺纹电镀后检验标准
螺纹作为最重要的机械紧固件，其表面大多采用电镀层来进行防腐和装饰，控制好螺纹电镀前尺寸是镀后尺寸合格的根本保证，也是许多螺纹加工企业在生产及检测过程的一大难题。
本文将螺纹产品镀前尺寸精度控制方法及检测方法加以归纳总结。
1、电镀层对螺纹几何参数的影响
假设镀层厚度在螺纹上是均匀分布的，则镀层对螺纹中径尺寸产生不同程度的影响，通常外螺纹中径的增大量是镀层厚度的4倍。
同样道理，内螺纹电镀后，其中径减少量也是镀层厚度的4倍。
实际上，由于零件的突出部位容易发生电力线过度集中，即产生所谓“尖端效应”，因此在制定电镀工艺时必须加以考虑。
2、螺纹电镀前尺寸的控制
为了使螺纹零件电镀后的尺寸合格，可以通过以下途径。
1）在耐腐蚀性能允许的条件下适当地减小镀层厚度，可以减少镀层厚度对配合尺寸的影响。
2）在零件性能允许的条件下，采用酸洗和化学抛光等工艺，事先对零件进行处理，预留零件需要电镀的厚度，以保证电镀后零件尺寸在图样要求范围内。
3）在零件机械加工过程中预留足够的镀层厚度尺寸。
4）选用耐腐蚀性更好的基体材料以减薄镀层厚度，或选用高耐蚀性镀层（在较低镀层厚度的情况下可达到同样的防护性能）来保证零件尺寸精度。
3、电镀螺纹的尺寸检测
在进行电镀螺纹检测时，根据GB/T5267.1，除非为满足功能需求，对螺纹或其他部位，明确规定允许尽可能地制出比标准螺纹更厚的镀层，否则，镀前尺寸应符合相关标准规定。
外螺纹：g、f、e；内螺纹：G 或H。
这些公差带优先用于电镀层。
电镀后，普通螺纹按照GB/T3943的规定：用公差带位置为h或H的通规分别检测外螺纹或内螺纹。