WX100 WORLDWIDE FASTENER STANDARD

 
WORLDWIDE FASTENER STANDARD
WX100  Date:  2011-12-23
 
 
Printed copies are uncontrolled  Copyright © 2011, Ford Global Technologies, LLC  Page 1 of 17
FINISH SPECIFICATION
 
1. SCOPE
 The following specifications cover requirements for finishes used on Worldwide Standard and Utility Parts.
 NOTE: Obsolete finish specifications are not shown in  this standard.  If a finish is referenced that is not
shown in this standard, the user should contact the local Fastener Engineering Office for direction.
 
2. APPLICATION
 Recommended Usage included in the description of individual finishes are intended for information only.
 
3. DESIGNATION
 
 The finish required on a standard or utility part is designated by adding the appropriate Finish Code to the
Part Number as a suffix when a part is released.  FINISH CODES SHALL NOT BE INCLUDED IN THE PART
NUMBER BLOCK ON A UTILITY PART DRAWING.
 The Finish Code is obtained from Clause 6, DETAILED FINISH DESCRIPTIONS AND REQUIREMENTS.
The Finish Code consists of letter 'S' followed by a number and designation alpha codes (except "SSW").
 The release for a standard or utility part is incomplete without the addition of a finish code to the Part Number.
WORLDWIDE PART NUMBERS MUST BE RELEASED WITH A WORLDWIDE FINISH NUMBER.
 
3.1 DESIGNATION EXAMPLE.   (NOT TO EXCEED 8 CHARACTERS)
 
Example S437MXA            S  437  M  XA
Standard/Utility Part Suffix Indicator
Worldwide Suffix Number (300 or 400 series)
Process/Color Indicator (M=Mechanical, non
Electrolytic B=Black L=Enhanced lubrication)
                    
Subsequent Treatment Indicator
 
 N0TE In the past, a number "1" after the S was used to indicate that the part was to be used in
an automatic assembly application.  This convention is no longer used.
 
 SUBSEQUENT TREATMENTS are treatments such as the addition of waxes for sealing on sheet
metal screws or wax on hose clamps to lower  the friction between the clamp and hose.  These
subsequent treatments are specified in WSS-M21P27-A1/A2/A3/A4…..etc
 
4. REFERENCES
ISO 261  ISO general-purpose metric screw threads - General plan
ISO 898-1  Mechanical properties of fasteners - Part 1: Bolts, screws and studs
ISO 898-2  Mechanical properties of fasteners - Part 2: Nuts with specified proof load values
ISO 4042 Clause 10 Threaded components - Electroplated coatings
ISO 6157-3  Fasteners - Surface discontinuities - Bolts, screws and studs for special
requirements
ISO 4599  Plastics, Determination of resistance to environmental stress cracking, Bent strip
method
QS-9000 Quality System Requirements
SAE/USCAR-1 Salt Spray Testing and Evaluation of Fastener Finishes
WD 950  Material and Performance Requirements for Spaced Thread Tapping Screws
WD 951  Mechanical and Performance Requirements of Case Hardened Thread Rolling
Screws
WD 952  Mechanical and Performance Requirements of Through Hardened and Carbon
Restored Thread Rolling Screws with Induction Hardened Points
WD 953  Material and Performance of Screws for Use in Plastics
WE 950  Prevailing Torque-Type Steel Hex Nuts and Hex Flange Nuts
WE 953  Mechanical and Performance Requirements for Single Thread Spring Nuts
WSB-M21P29-A1 Corrosion Protective Coating, Zinc, Chromate, Organic, Baked 
WORLDWIDE FASTENER STANDARD
WX100  Date:  2011-12-23
 
 
Printed copies are uncontrolled  Copyright © 2011, Ford Global Technologies, LLC  Page 2 of 17
 
WSB-M10P10-AX Chromate Finish
WSD-M1P85-A1/A2 Plating, Zinc over Ferrous Surfaces
WSD-M13P7-A Lubricant-Torque/Clamping Force Control
WSD-M21P10-/B2/B3 Corrosion Protection Coating-Organic Type
WSD-M21P11-B1/B8 Corrosion Protective Coating - Zinc Organic Type
WSD-M21P13-A3 Corrosion Protective Coating - Zinc/Chromate/Combination Type
WSS-M21P17-B3 Electrolytic Zinc Plate, Chromate, Leached and Sealed, Integral Torque Control
Lubricant
WSS-M21P17-B4 Mechanical Zinc Plate, Chromate, Leached and Sealed, Integral Torque Control
Lubricant
WSS-M21P28-A2 Corrosion Protective Coating, Organic Polymer, Friction-Modified
WSS-M99A3-A Embrittlement Avoidance
WSS-M99P9999-A1 Restricted Substance Management Standard
WX 200  Threaded Fasteners with Dry Film Microencapsulated Adhesive Applied to the
Threads
WX 201  Threaded Fasteners with Sealer Compound Applied to the Threads
WZ 100/101  Steel ISO Metric Threaded Fasteners Torque/Clamping Force Performance.
 
5. GENERAL REQUIREMENTS.
 
5.1 SUMMARY
 All parts must comply with Engineering Material Specification WSS-M99P9999-A1 to help safeguard
health, safety and the environment.
 
5.2 PART CONDITION
 Parts as supplied to Ford locations shall be completely covered with the finish specified.  Parts shall
also be commercially clean and shall be free from corrosion, chips, loosely adherent metal oxides, dirt,
abrasives or other foreign material.  Handling, storage, packaging, preservation, and delivery shall be in
accordance with QS-9000. 
 
5.3 EMBRITTLEMENT AVOIDANCE
  All components shall comply with the requirements of WSS-M99A3-A.  Spaced thread tapping screws
per WD950 may be electroplated.  Thread rolling screws per WD 952 used in grounding applications
may be electroplated only in accordance with S450 or S450L.
 
5.4 PROTECTIVE FINISHES ON THREADS
 Bolt threads with relatively thick coatings (e.g. greater than 8 micrometres) may require additional
allowance to accommodate the coating.  The thread dimensions before coating shall be determined by
the Supplier and shall be manufactured within tolerance class 6 limits.  The thread allowance shall be
limited by the upper deviation of tolerance class 6g (es) and the lower deviation of tolerance class 6e
(ei).
 Note: This allows the manufacturer to size the parts anywhere within the total tolerance span of class
6g (es) through 6e (ei).  To minimize deviation within a lot, the lot shall be limited to a tolerance grade 6. 
See ISO 965 for information regarding thread tolerances.
 After plating/coating the threads shall meet the requirements of tolerance class 6h using a solid GO
screw ring gauge.  For acceptability of thread damage after plating/coating the torque applied to the
solid GO screw ring gauge shall not exceed 0.001d3
 Nm, except for dip spin coatings which shall not
exceed 0.0015d3
Nm.
  Nut threads shall be manufactured to 6H tolerance.  When coated with zinc flake type coatings
tightness to thread inspection gauges may be experienced, however, the coating thickness shall not
adversely affect the mechanical performance of the nut or have an adverse effect on normal installation
practices.  Zinc flake coated nuts shall be tested using an uncoated (or zinc plated) 6g bolt.  The nut
shall engage on the bolt by hand, the maximum prevailing torque measured over a minimum of 1.5d of
rotations shall not exceed 1Nm.
 
WORLDWIDE FASTENER STANDARD
WX100  Date:  2011-12-23
 
 
Printed copies are uncontrolled  Copyright © 2011, Ford Global Technologies, LLC  Page 3 of 17
5.5 TEST METHODS - SPECIAL REQUIREMENTS FOR FASTENERS
 
 Requirements defined in this protective finish specification apply to parts as received by Ford and shall
be evaluated using the following test methods and definitions as applicable.
 
5.5.1 SIGNIFICANT SURFACES
 Significant surfaces are those surfaces visible on a part as normally assembled, or surfaces that
can be a source of corrosion products visible on an assembled vehicle.  Significant surfaces are
used when assessing corrosion.
 
5.5.2 COATING THICKNESS
 Threads, sharp edges, crevices, holes, slots and recesses shall not be used for coating thickness
measurement.  The measurement of coating thickness shall be in accordance with ISO 4042
Clause 10.
 
5.5.3 SALT SPRAY TEST
 Salt spray tests shall be conducted in accordance with SAE/USCAR-1, which supersedes any
salt spray requirements stated in the specified material/performance specifications.  It is not
intended for salt spray testing to be conducted on every lot.  Salt spray testing is intended to be
used to monitor the process and shall be conducted in accordance with QS-9000.
 
5.5.4 WASHER ADHESION
 The washer component of nut and washer assemblies and bolt and washer assemblies shall be
free to rotate so that installation is not affected by spinning of the washer component.  The
washer may not be free spinning initially, when  heavy finishes are applied.  Acceptable initial
washer component adhesion shall become loose after a 0.0015d3
 [Nm] breakaway torque is
applied.
 
5.6 DIP SPIN APPLIED COATINGS - RECESS FILL, THREAD FILL, AND OTHER POTENTIAL ISSUES
5.6.1 Some finishes are applied by: a) depositing the fasteners into a perforated basket; b) immersing
the basket into a tank of the uncured material; c) elevating the basket above the tank; and e)
spinning the basket above the tank.  The basket's rotational speed overcomes the centripetal
force, shedding excess material to provide the  desired coating thickness.  Material viscosity,
fastener geometry, fastener orientation in the basket, load size, and rotational speed are major
factors in the application of these finishes.
 
5.6.2 Internally driven fasteners (recess drive), fasteners with internal cavities such as nuts, rivets,
parts with extruded, closed-end holes, parts with through-holes, fasteners with fine pitch threads,
and other similar features trap excess material in the cavities, which the spinning process does
not completely remove.
 
5.6.3 CAUTION: If the dip spin process is used  to apply coatings to fasteners with these design
features, a percentage of the fasteners will have recess fill, clogged holes, bubbled coating,
and/or thread bridging.  As a result, fasteners with these finishes and designs may experience
issues with form, fit, and function at the assembly plants.
 
5.6.4 To avoid these issues, consider applying the  dip spin finish using a different process method
such as spray, tumble spray, and planetary rotary systems.  These processes may significantly
reduce recess fill, but will still yield some recess fill.  Alternatively, consider externally driven
fastener designs, non-dip spin finishes, and plated finishes.
 
Note: Dip Spin coatings are identified under their respective finish descriptions within this specification.
 
 
WORLDWIDE FASTENER STANDARD
WX100  Date:  2011-12-23
 
 
Printed copies are uncontrolled  Copyright © 2011, Ford Global Technologies, LLC  Page 4 of 17
 
5.7 MECHANICALLY DEPOSITED PLATINGS – BEAD ENTRAPMENT
 
5.7.1 Mechanical plating, also known as peen plating, mechanical deposition, or impact plating, is a
plating process that imparts the coating by cold welding fine metal particles to a workpiece.  It is
commonly used to overcome the potential for  hydrogen embrittlement.  The process involves
tumbling the workpieces with a mixture of water, metal powder, media, and additives.  The media
material is usually  soda lime glass or a  ceramic and is usually  spherical in form.  Common
coating materials are zinc, tin, copper, and aluminum.
 
5.7.2 Internally threaded fasteners and fasteners with an integrated or free-spinning assembled
washers such as nut and washer assemblies (KEPS) or screw and washer assemblies (SEMS)
have the potential for bead entrapment in the thread form, between the assembled washer or
other part cavities, which the mechanical plating process does not completely remove.  To
prevent the potential from impeding the assembly process or functionality of the fastener,
mechanical plating shall not be released on these parts.  This provision applies to all thread sizes
and forms.
 
6. DETAILED FINISH DESCRIPTIONS AND REQUIREMENTS
 
 SSW IN WHITE (COLOR KEYED) PARTS
 When Standard or Utility parts are designated "In White" and are therefore required to comply with a color
chart or master sample, they shall be released with the suffix SSW.
 
 S300 PLAIN: No supplementary finish required other than  the finish considered the normal result of
manufacturing processes for the material and product involved.
 
Total Thickness: Not applicable
Lubricant:  ISO general purpose metric screw threaded steel fasteners whose thread form is
in accordance with ISO 261 and/or whose material and performance requirement
reference ISO 898-1 or 898-2 shall be lubricated per WSD-M13P7-A.
Color: Not applicable
Specifications:  WSD-M13P7-A
Corrosion Protection:  None
Service Temperature: Not applicable
Coating Process:  Not applicable
Friction Coefficient u=0.15 +/-0.03 per WZ101 Program B using test surfaces per WZ100.
Approved Source: Any Reliable Supplier
Tox Number:  Not Applicable
 
Special Requirements:  Lubricated parts shall meet the requirements for torque/clamping force specified in
WZ 100 or the requirements of the individual product specification, e.g., Prevailing
Torque Nuts WE 950.  Weld, Pierce, Clinch and non-metallic fasteners shall not
be lubricated.  All other fasteners that do not fully conform to the aforementioned
requirements shall not be lubricated, e.g., Tapping Screws WD 950/953, Single
Threaded Spring Nuts WE 953.
Recommended Usage:  Used for internal engine/transmission applications or where subsequent
processing adds protection. Also used for non-metallic fasteners which require no
protection.  Products which require lubrication only to aid in assembly, such as,
pierce products, and blind rivets should be released as S300XB (see WSS-
M21P27-A1/A2/A3).
 
 
WORLDWIDE FASTENER STANDARD
WX100  Date:  2011-12-23 
 
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