ENGINEERING MATERIAL SPECIFICATION

COATINGS, STEEL SHEET WSS-M1P94-A

1. SCOPE

This specification defines the requirements for coil coatings on steel sheet. These coatings comprise 4
categories:

. Zinc Based Metallic (i.e. Zinc, Zinc/Iron, Zinc/Nickel and other Zinc/Alloy)
. Other Metallic (i.e. Nickel, Tin)
. Organic (i.e. Zinc Rich Primer)
. Phosphate (Upon request from the Stamping Plant to the responsible
Materials Engineering Activity, there is the option of using prephosphated material to aid formability).

Such coatings shall be specified in conjunction with the appropriate base steel sheet. The currently
released base steel specifications are:

Specifications released for regional use (prior to 2012): (All Regional Specs N-Status)
WSS-M1A183-D
WSB-M1A215-E1/F1
WSD-M1A333-A1/A2/A3/A4
WSS-M1A338-A1
WSS-M1A341-A1/A2/A3/A4/A5/A6/A7/A8/A9/A10/A11/A12
WSS-M1A344-A1/A2
WSS-M1A345-A1/A2/A3/A4
WSS-M1A346-A1/A2/A3/A4/A5/A6
WSS-M1A347-A1/A2/A3/A4/A5/A6
WSS-M1A348-A1/A2/A3/A4/A5/A6/A7/A8/A9

Specifications released for global use (2012 and later):

WSS-M1A365-A11/A23
WSS-M1A367-A11/A53
WSS-M1A368-A11/A91

2. APPLICATION

This specification was released originally for material used for automobile body and chassis parts
requiring good corrosion resistance. The category of Other Metallic Coatings was incorporated
originally for fuel systems parts requiring good corrosion resistance.

Note: Good quality paintability depends upon the critical factors of chemical cleanliness and
crystalline integrity of the phosphate coating. Accordingly, prudence should be exercised when
considering a pre-phosphate coating on exterior facing surfaces e.g. skin panels.
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Note: The presence of a coating will influence the properties of the final coated product, compared to
the uncoated base steel sheet.

Note: Rinses used during the coating process must be hexavalent chromium free.

Date Action Revisions Rev 04

2019 04 01 Revised See Summary of Revisions D. Ruhno
2012 07 31 Revised Para 1, 3.5, 3.10, 5.8 revised. 5.9 added. A. Toennessen, D Jordan NA
1996 02 15 Activated K. Thurgood
Controlled document at www.MATS.ford.com
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 ENGINEERING MATERIAL SPECIFICATION

WSS-M1P94-A

3. REQUIREMENTS

3.1 APPROVED SOURCES

This specification is performance based. The Engineering Approved sources for coatings will
be listed against the appropriate Base Steel Sheet Engineering Material Specifications.
Reference the pertinent substrate specification in addition to section 4.3 of this specification
for additional requirements for Approved Sources.

3.2 FORMABILITY

The formability paragraph of the appropriate Base Steel Sheet material specification shall apply.

3.3 JOINABILITY

The weldability paragraph of the appropriate Base Steel Sheet material specification shall apply.

3.4 PAINTABILITY

The paintability para of the appropriate Base Steel Sheet material specification shall apply.

3.5 COATING: ZINC BASED METALLIC

3.5.1 Coating Mass

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(ASTM A90)
Standard Range
Coating Mass Coating Mass Per Side g/m2
Designation Single Spot min/max*

Hot Dipped** Electrolytic**

00 NA 0
20 20/50 20/30
30 30/60 30/45
40 40/70 40/55
45 45/75 45/60
50 50/80 50/70
55 55/85 55/75
60 60/90 60/80
70 70/100 70/90
98 100/130 100/130

In some instances, coatings that are produced to tighter coating mass ranges than
shown above may be available. These shall be designated as 'Restricted Coating'
(Symbol 'C') and shall be detailed on the appropriate Engineering Drawing as follows:

Restricted Range
Coating Mass Coating Mass Per Side g/m2
Designation Single Spot min/max*

Hot Dipped** Electrolytic**

50 50/70 50/65
55 55/75 55/70
60 60/80 60/75
70 70/90
98 100/130
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*ASTM A90 should be suitably modified to allow coating mass determinations on

individual sides.

**Where these tolerances cannot be met, exceptions must be approved by the

responsible activity.

3.5.2 Coating Composition (Electrolytic)

Unless an alloy coating is chosen, the primary deposit shall be Zinc. Electrolytic
Zinc/Nickel shall contain 10.5 - 13.5% Nickel. Electrolytic Zinc/Iron shall contain 12 -
18% Iron. The frequency of testing and the analytical method shall form part of the
control plan.

3.5.3 Coating Composition (Hot Dipped)

Unless an alloy coating is chosen, the primary deposit shall be Zinc. The frequency of
testing and the analytical method shall form part of the control plan (see also para
4.3).

3.5.4 Supplementary Coatings

Unless otherwise stated (see para 3.7 and 3.8), no supplementary coatings (other
than a company approved mill oil (rust preventative oil) or prelube) are permitted.

3.5.5 Coating Adhesion

(ASTM A924M/ASTM A879M)

Coated steel shall conform to the coating bend test requirements of ASTM A 924M for
hot dipped and ASTM A879M for electrolytic coated products. The frequency of
testing shall form part of the control plan.

3.5.5.1 Coating Bend Test

(ASTM A924M/ASTM A879M)

Coated Steel shall conform to the coating bend test requirements of

ASTM A924M for hot dipped and ASTM A879M for electrolytic coated
products. The frequency of testing shall form part of the control plan.

3.5.5.2 Adhesive Shear Test

(SAE J1523 or ISO 4587)
For All Coating Types

At a frequency to be negotiated with Materials Engineering (as part of the

Source Approval Process) and incorporated into the control plan, the
following:

When tested according to SAE J1523 or ISO 4587 (0.8 mm. thickness
specimen; additional bonding thickness of 0.25 mm.) using a high
strength structural epoxy adhesive such as WSK-M2G329-A3, the
coating (ie. zinc or zinc/alloy) shall remain adherent to the steel substrate
up to a minimum shear strength requirement of 8 MPa.

For relevant Engineering Drawings, component engineers are

recommended not to specify a minimum shear strength requirement
lower than 8 MPa.
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 ENGINEERING MATERIAL SPECIFICATION

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3.5.6 Coating Wraparound and Edge Condition

For one side coated products, traces of coating are allowed on the uncoated side of
the sheet from the edges to 15 mm from coil edges. No coating is allowed on the
remainder of the uncoated side.

The amount of coating on the strip edge shall be no greater than the maximum
stipulated in para 3.5.1 and of sufficient adhesion to prevent flaking during the
manufacturing process.

3.5.7 Coating Appearance

For hot dipped products, the coating shall be minimum spangle and when viewed at
1X the individual zinc crystals shall be no longer than 5 mm across the maximum
dimension. The need for a final temper mill reduction to control surface appearance
or formability is to be negotiated between the manufacturing activity and the coater.

3.6 COATING: OTHER METALLIC

3.6.1 Tin

3.6.1.1 Coating Mass

(ASTM A630)

Coating Mass Coating Mass Per Side g/m2

Designation Single Spot min/max*

Hot Dipped Electrolytic

20 20/50 20/35
35 35/65 35/50
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50 50/80 50/65
65 65/95 65/80

*ASTM A630 should be suitably modified to allow coating mass

determinations on individual sides in SI units.

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 ENGINEERING MATERIAL SPECIFICATION

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3.6.2 Nickel

3.6.2.1 Coating Mass

(ASTM B530)
(with a multiplication factor of 8.90)

Coating Mass Coating Mass Per Side g/m2

Designation
Electrolytic

25 25/40
35 35/50
45 45/60

3.6.3 Coating Bend Test

(ASTM B 571)
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No peeling or flaking of the coating is permitted.

3.6.4 Edge Condition

The amount of coating on the strip edge shall be no greater than the maximum
stipulated in para 3.6.1.1 and 3.6.2.1 and of sufficient adhesion to prevent flaking
during the manufacturing process.

3.6.5 Coating Appearance

The coating shall have a workmanlike appearance and shall not have defects of a
nature or degree for the grade and quality ordered that will be detrimental to the
fabrication of the finished part. The need for a final temper mill reduction to control
surface appearance or formability is to be negotiated between the manufacturing
activity and the coater.

3.7 COATING: ORGANIC - ZINC RICH PRIMER

3.7.1 Base Material

Between the appropriate Base Steel Sheet and the Zinc Rich Primer layer shall be a
Zinc Based Metallic layer, usually Electrolytic Zinc/Nickel.

3.7.2 Pretreatment Layer

A conductive Inorganic/Zinc Dust complex shall be used to give a satisfactory bond

between the Zinc Based Metallic (usually Electrolytic Zinc/Nickel) layer and the
Conductive Organic layer.

3.7.2.1 Coating Weight (as Cr), g/m2 0.38 +0.10/-0.05

3.7.3 Conductive Organic Layer

This shall comprise an Epoxide Binder (Epoxy Resin) modified with Zinc Particles.
The control plan referred to in para 3.1 shall address conductive organic layer
composition and consistency of electrical conductivity.

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 ENGINEERING MATERIAL SPECIFICATION

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3.7.3.1 Coating Thickness, Micrometers 9 +2.5/-1.5

(ISO 2808)

3.7.4 Coating Appearance

The coating shall have a workmanlike appearance and shall not have defects of a
nature or degree for the grade and quality ordered that will be detrimental to the
fabrication of the finished part.

3.7.5 Coating Bend Test

(ASTM B 571)

No peeling, flaking or interlayer separation of the coating is permitted.

3.8 COATING: TRI-CATIONIC PHOSPHATE

3.8.1 Base Material

Between the appropriate Base Steel Sheet and the Phosphate layer shall be a Zinc
Based Metallic layer, usually Electrolytic Zinc or Hot Dipped Zinc/Iron.

3.8.2 Phosphate Layer

When approved by the responsible Materials Engineering Activity, a suitable Tri-

Cationic (Zinc/Nickel/Manganese) Automotive Quality Phosphate shall be used. This
section shall constitute part of the control plan (see para 3.1). Such phosphating shall
not be detrimental to any other para, particularly 3.4. Attention is also drawn to para
3.2.

3.8.2.1 Coating Weight g/m2 1.5 +/- 0.3

(FLTM AQ 101-01)

3.9 COIL COATED FINAL PRODUCT IDENTIFICATION

Unless an alternative method is agreed upon by the coated steel supplier and Manufacturing
activity, the coil coated final product shall be identified as follows:

This information shall be marked on the more heavily coated side of a one-sided or differentially
coated product and on the unexposed side of equally coated products for exposed surfaces and
shall be repeated at 1 meter intervals.

. Steel Company Name and Location

. Coater's Name (if different from above)
. Date Coated

3.10 COATING DESIGNATION

In addition to the base steel sheet specification, engineering drawings shall show a coating
designation which identifies the coating mass of each side, the coating composition of each side
and the method of coating (Electrolytic and/or Hot Dipped) as follows:

. 1st and 2nd characters: The coating mass designation of one side (the unexposed side or
heavier coated side).

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. 3rd character: The coating composition of the unexposed side or heavier coated side
where G = Zinc, A = Zinc/Iron, N = Zinc/Nickel, T = Tin, K = Nickel and X = other than G, A,
N, T or K.

. 4th and 5th characters: The coating mass designation of the opposite side (the exposed
side or lighter coated side).

. 6th character: The coating composition of the opposite side where G = Zinc, A = Zinc/Iron,
N = Zinc/Nickel, T = Tin, K = Nickel and X = Other than G, A, N, T or K.

7th and 8th characters:

Specifications released for regional use (prior to 2012):

HD: Hot dip galvanized (continuous strip, used for galvanized and galvannealed type)
EL: Electrolytic deposition (continuous strip)

Specifications released for global use (2012 and later):

GI: Hot dip galvanized (continuous strip)

GA: Hot dip galvannealed (continuous strip)
EG: Electrolytic deposition (continuous strip)
UC: Uncoated

9th character: (used to mark “restricted” zinc coatings only)

C = Restricted Coating Mass

10th character: P = (Pre-) Phosphate

Specifications released for global use (2017 and later):

E = Exposed surface quality

U = Unexposed surface quality
See currently released base steel specifications for additional information on surface quality.

NOTE: See paragraph 4.8 for drawing callout examples.

4. GENERAL INFORMATION

The information given below is provided for clarification and assistance in meeting the requirements of
this specification. Contact gmfs@ford.com for questions concerning Engineering Material
Specifications.

4.1 DOCUMENT ORIGIN

This document was modified in 1999 and subsequently, as a collaborative effort between Ford
Motor Company, Mazda (Mazda Motor Corporation) and Jaguar (Jaguar Cars), part of PAG
(PAG is Premier Automotive Group).

4.2 ENGINEERING SOURCE APPROVAL BY FORD

The Engineering Approved sources for coatings will be listed against the appropriate Base Steel
Sheet Engineering Material Specifications.

4.3 INITIAL SUPPLIER APPROVAL BY FORD

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For initial approval, the supplier should furnish the following information for each coating
designation/coating line combination.

. A plan detailing how each requirements of para 3 will be controlled on a continuing

production basis.

. Test results from a typical production sample for the requirements outlined in para 3.

. Test results from typical production samples for paintability requirements outlined in para 3.4.

. Typical coating chemical analysis. For products coated by Hot Dipping, coating composition
should be determined by analysis of samples taken from the molten bath. For
Electrodeposited coatings, composition should be as deposited.

. Coating mass histogram including mean and standard deviation values. Data should consist
of a minimum of 500 mass measurements randomly taken from each side of a minimum of
20 coils while the process is operating in statistical control.

Upon approval, the material will be added to the Engineering Material Approved Source List
(see para 4.2).

4.4 COATING COMPOSITION (HOT DIPPED)

Hot Dipped Zinc and Hot Dipped Zinc/Iron usually contain Aluminum to aid adhesion of the
coating to the base steel. The proportion of Aluminum in the coating varies with coating thickness
but rarely exceeds 1%. Additionally, Hot Dipped Zinc/Iron usually contains 8 - 12% Iron.

4.5 COATING THICKNESS

If it is desired to estimate the thickness of the coating from the coating mass, the following factors
(per side) shall be used:

. Zinc (Hot Dipped or Electrolytic) 7.14 g/m2 = 1 micron

. Zinc/Nickel (Electrolytic) 7.35 g/m2 = 1 micron
. Zinc/Iron (Electrolytic) 7.25 g/m2 = 1 micron
. Zinc/Iron (Hot Dipped) 7.21 g/m2 = 1 micron
. Tin 7.30 g/m2 = 1 micron
. Nickel 8.90 g/m2 = 1 micron
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(Note: 1 micron = 1 micrometer = 0.001 mm)

4.6 REFERENCE DOCUMENTS

WSS-M1A183-D ASTM A90

WSB-M1A215-E1/F1 ASTM A879M
WSD-M1A333-A1/A2/A3/A4 ASTM A630
WSS-M1A338-A ASTM A924M
WSS-M1A341-A1/A2/A3/A4/A5/A6/A7/A8/A9/A10/A11/A12 ASTM B530
FLTM AQ 101-01 ASTM B571
JFS A 3011 ISO 2808
JFS A 3021
WSS-M1A344-A1/A2
WSS-M1A345-A1/A2/A3/A4
WSS-M1A346-A1/A2/A3/A4/A5/A6
WSS-M1A347-A1/A2/A3/A4/A5/A6
WSS-M1A348-A1/A2/A3/A4/A5/A6/A7/A8/A9
WSS-M99P1111-A
WSS-M1A365-A11/A12/A13/A14/A15
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WSS-M1A367-A11/A12/A21/A22/A23/A33/A34/A35/A36/A37/A38
WSS-M1A368-A13/A14/A81/A82/A83/A84/A91/A92

4.8 METHOD OF SPECIFYING

The specification on the Engineering Drawing shall include the Base Steel Sheet, the
Coating(s), and, if applicable, the Surface Quality.

Zinc Coatings

e.g. Steel, Sheet, Bake Hardenable, 210 MPa minimum as received yield strength, coated
with double sided Hot Dipped Zinc for a visible exterior body panel, would be specified
thus:

. Steel to WSS-M1A341-A4, Coated to WSS-M1P94-A: 50G50G-HD, Class 1

. Steel to WSS-M1A367-A22, Coated to WSS-M1P94-A: 50G50G-GI, E

e.g. Steel, Sheet, Cold Rolled, Low Carbon, coated with double sided Electrolytic or Hot

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Dipped Zinc for a non-visible structural part, would be specified thus:

. Steel to WSD-M1A333-A2, Coated to WSS-M1P94-A: 50G50G-EL/HD, Class 3

e.g. Steel, Sheet, Cold Rolled, Low Carbon, coated with double sided Hot Dipped Zinc for a
non-visible structural part, would be specified thus:

. Steel to WSD-M1A333-A2, Coated to WSS-M1P94-A: 50G50G-HD, Class 3

. Steel to WSS-M1A365-A12, Coated to WSS-M1P94-A: 50G50G-GI, U

Other Metallic Coatings:

e.g. Steel, Sheet, Cold Rolled, Low Carbon, coated with double sided Electrolytic Tin, would
be specified thus:

. Steel to WSD-M1A345-A2, Coated to WSS-M1P94-A: 50T50T-EL, Class 3

. Steel to WSS-M1A365-A12, Coated to WSS-M1P94-A: 50T50T-EG, U

e.g. Steel, Sheet, Cold Rolled, Low Carbon, coated with double sided Electrolytic Nickel,
would be specified thus:

. Steel to WSD-M1A333-A2, Coated to WSS-M1P94-A: 25K25K-EL, Class 3

. Steel to WSD-M1A365-A12, Coated to WSS-M1P94-A: 25K25K-EG, U

5. SUMMARY OF REVISIONS

2019 04 01
- Section 1: Reference pre 2012 regional specs as “N-Status”
- Section 1: Update global spec grades released for use
- Section 3.1: Revised Approved Source paragraph wording
- Section 3.3: WELDABILITY changed to JOINABILITY, removed references to regional specs
- Section 3.5.5 Revised wording for Adhesive Shear Test requirements
- Section 3.5.6 Removed reference to requirements for single sided coating (no longer used)
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- Section 3.6.4 Removed reference to requirements for single sided coating (no longer used)
- Section 3.10 Added E = Exposed and U = Unexposed for 2017 & later
- REMOVED CROSS REFERENCE OF SPECIFICATIONS section
- Section 4.7
o Removed reference to FLTM BA 113-01
o ASTM A591 updated to ASTM A879M
o Removed reference to Mazda MES MM specifications
- Section 4.8 updated examples to include new E and U nomenclature

2012 07 31
- Added global steel specifications to paragraph 1
- Clarified standard and restricted coating weight ranges in paragraph 3.5.1
- Added new hot dip and electrolytic nomenclature for global steel specifications in para 3.10
- Updated reference documents in paragraph 4.7 and clarified examples in paragraph 4.8
- Added Summary of Revisions and renumbered.

2003 07 31 Revised Para 3.0 inserted; Para 3.1, 3.11, 4 deleted

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