Klass.-Nr. 50 20 0; 02 64 2 February 2005
Surface Protection of Metal Parts
Surface Protection Types, Codes
VW
137 50
Konzernnorm
Descriptors: corrosion, rust protection, surface protection, metal, protection type,
code, corrosion protection
Page 1 of 23
Fachverantwortung/Responsibility Normung/Standards (EZTD, 1733)
K-QS-32/2 Koeppen Tel:-25803 Laudien Dr. Eisenberg Wiesner Tel: +49-5361-9-29064 Sobanski
Confidential. All rights reserved. No part of this document may be transmitted or reproduced without permission of a Standards Department of the Volkswagen Group.
Parties to a contract can only obtain this standard via the B2B supplier platform “www.vwgroupsuppy.com”.
VOLKSWAGEN AG
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Contents
Page
1 Scope .................................................................................................................................. 2
2 Description .......................................................................................................................... 3
2.1 Code structure..................................................................................................................... 3
2.2 Example of description........................................................................................................ 3
3 Requirements...................................................................................................................... 3
3.1 General requirements ......................................................................................................... 3
3.2 Drawing specifications ........................................................................................................ 4
3.3 Weldability........................................................................................................................... 4
3.4 Agents impairing wetting ability ........................................................................................... 4
3.5 Friction behavior.................................................................................................................. 5
3.6 Zinc coatings ....................................................................................................................... 5
3.7 Screws, nuts, threaded parts and shaped parts.................................................................. 5
3.8 Commercial surface protection types.................................................................................. 5
3.9 Parts without surface protection.......................................................................................... 6
3.9.1 Joining elements ................................................................................................................. 6
3.9.2 Other parts (e.g. sheets) ..................................................................................................... 6
3.10 Assignment of surface protection types and codes............................................................. 6
4 Referenced standards....................................................................................................... 12
A.1 Comparison of “not for new design”/“for new design” ....................................................... 14
A.2 Surface protection types without code .............................................................................. 15
A.3 Surface protection types according to VDA test sheet 235-104 and VW 137 50.............. 15
A.4 Invalid Ofl descriptions ...................................................................................................... 16
Changes
The following changes have been made as compared to Volkswagen standard
VW 137 50, 1999-04:
� Surface protection type “phosphated, passivated” (code b101) stipulated.
� Surface protection type “phosphated, silver gray (for internal applications)” (code b111)
stipulated.
� Surface protection type “phosphated, yellow glazing, for internal applications (water-based
paint)” (code b112) stipulated.
� Surface protection type “manganese phosphated” (code b130) restricted in terms of the
possible applications (no longer permitted for new design of joining elements, replacement is
b140).
� Cr(VI)-free surface protection types “electrolytically zinc-coated” (codes c341, c641, c342,
c642, c343, c643, c347, c647, c696 and c697) added.
� Cr(VI)-containing surface protection types “electrolytically zinc-coated” (codes c350, c650,
c351, c651, c355, c360, c660, c683, c385, c685) restricted in terms of the possible
applications (no longer permitted for new designs, for replacement see Table A.1).
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VW 137 50: 2005-02
� Surface protection type “bright chrome-plated, with microcracks” (code f320) removed
(replaced by Ofl-f350).
� Layer thicknesses for surface protection types “tin-coated” (code g...) stipulated.
� Surface protection types for electrolytically deposited Al and Al/Mg alloy coatings (codes q600,
q605, q610, q615) added.
� Cr(VI)-containing surface protection types “Zn/Fe alloy coated” (codes r600, r605, r610, r620
and r630) restricted in terms of the possible applications (no longer permitted for new designs,
for replacement see Table A.1).
� Cr(VI)-free surface protection types “Zn/Fe alloy coated” (codes r301 and r302) added.
� Surface protection types “Zn/Ni alloy coated” (codes r640, r650, r660, r665, r670, r675)
restricted in terms of the possible applications (no longer permitted for new designs, for
replacement see Table A.1).
� Cr(VI)-free surface protection types “Zn/Ni alloy coated” (codes r642, r643, r649, r672, r673
and r677) added.
� Cr(VI)-free surface protection types “duplex coated” (codes s611, s617, s621 and s627)
added.
� Cr(VI)-containing surface protection types “duplex coated” (codes s610, s615, s620 and s625)
restricted in terms of the possible applications (no longer permitted for new designs, for
replacement see Table A.1).
� Surface protection types “zinc flake coatings” (codes t300, t310, t320, t345, t600, t620 and
t645) restricted in terms of the possible applications (no longer permitted for new designs, for
replacement see Table A.1).
� Cr(VI)-free surface protection types “zinc flake coatings” (codes t602, t611, t615 and t647)
added.
� Surface protection type “black finished” (code u110) re-included.
� Cr(VI)-containing surface protection type “chromated” (code v110) restricted in terms of the
possible applications (no longer permitted for new designs, replaced by Ofl-v111).
� Cr(VI)-free surface protection type “Cr(VI)-free passivated” (code v111) added.
� Surface protection type “anodized” (code w650) removed.
� Surface protection types “coil-anodized” (codes w660 and w670) restricted in terms of the
possible applications (no longer permitted for new designs).
� Surface protection types “anodized” (codes w180, w680, w690, w695) added.
� Surface protection type “multi-layer coated, medium protection” (code x310) removed.
� Surface protection types “multi-layer coated, heavy protection” (codes x611, x612 and x613)
added.
� Surface protection types “zinc-dust paint coating” (codes y600 and y650) re-included.
� Specifications for parts without surface protection (Section 3.9) formulated in more detail.
� Comparison list of VDA/Volkswagen descriptions (Table A.3) included.
Previous issues
1953-06; 1954-07; 1956-10; 1958-04; 1959-03; 1959-06; 1963-03; 1963-05; 1966-06; 1966-10;
1967-05; 1967-11; 1969-10; 1970-11; 1971-12; 1972-02; 1974-08; 1975-06; 1976-07; 1980-09;
1983-10; 1986-10; 1989-12; 1991-11; 1994-10; 1999-04
1 Scope
This standard applies to the identification of general surface protection types of vehicle parts and
units in drawings and technical documentation. Separate technical supply specifications
(TL standards) apply to special surface protection types without identification by surface code (see
Appendix A.1).
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VW 137 50: 2005-02
2 Description
2.1 Code structure
The abbreviation for surface protection ('Ofl-' from the German word for 'surface') is followed by a
code with four characters, taken from Table 2.
2.2 Example of description
Surface protection: electrolytic zinc alloy coating, transparent Cr(VI)-free passivated, with lubricant
treatment, heavy protection, according to TL 244.
VW 137 50 – Ofl-r645
3 Requirements
3.1 General requirements
The vehicle parts and units are categorized according to their corrosion load and assigned to
a protection class with grade (according to Table 1) by the responsible Engineering Department
upon agreement with the Volkswagen AG Central Laboratory (K-QS-32) and/or the AUDI AG
Test Laboratory (I/GQ-322).
Table 1 – Classification of vehicle parts
Vehicle part categories Corrosion load Protection class
Parts with the following features:
(a) non-visible in installed condition,
(b) corrosion protection serves only
as protection for transportation,
(c) corrosion protection is not needed
for proper performance.
Minor load. Light protection
grade 1
Interior and exterior components
in a protected installation position.
Not for joining elements (for exceptions
see VW 011 10).
Medium load. Medium protection
grade 3
Parts that are subjected to direct open-air
weathering (e.g. chassis, engine,
transmission).
Parts that are visible in installed condition
(also seen from the vehicle underside).
Parts with the following features:
(a) corrosion protection is required
to ensure proper performance and
(b) use in the interior and exterior due
to reduction of material types policy,
e.g. joining elements.
Heavy load. Heavy protection
grade 6
Finish, appearance and post-treatment
Protection class
Type of method
Abbreviation for surface protection
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VW 137 50: 2005-02
The restrictions stipulated in VW 603 61 must be observed for mechanical joining elements.
The following standards apply to thread dimensions prior to surface treatment: VW 116 10,
VW 116 14, VW 116 24, VW 116 25 and VW 116 27. For thread dimensions after surface
treatment, VW 116 11 and VW 116 15 apply.
All-metal clamping nuts must always be treated with additional or integrated lubricants.
Avoidance of hazardous substances according to VW 911 01. The coatings used must be free of
compounds containing Cr(VI) or lead.
3.2 Drawing specifications
If a certain surface protection is required for the entire part or for several parts in an ASSY, the
code shall be entered in the surface protection title block; e.g. Ofl-t650 (see also VW 010 58). If
several surface protection types can be applied optionally, the codes for all permissible treatments
shall be given,
e.g. Ofl-r673/x630.
If only partial protection is applied to a part, “see drawing” shall be entered in the surface protection
title block; a wide dash-dot line with a datum line (see Figure 1) marks the given area on the part.
If there is only a small area on the part that is without surface protection, the unprotected area shall
be marked (Figure 2). In this case “see drawing” shall be entered in the surface protection
title block.
Figure 1 Figure 2
If different surface treatments are required for a part, “see drawing” shall be entered in the surface
protection title block. The given areas on the part shall be clearly indicated.
If parts from one ASSY are separately coated (one or more different surface treatments), “see
drawing” shall be entered in the surface protection title block of the assembly drawing. The surface
treatments shall be referred to separately in the part-related drawings.
3.3 Weldability
If parts with surface protection are to be welded to each other or to other metal parts, the parts
shall be tested for weldability. Ofl-c340 shall be provided as the standard surface protection.
3.4 Agents impairing wetting ability
Lubricants and slushing oils shall be free of silicone oils and other agents that significantly impair
wetting ability.
without surface protection
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VW 137 50: 2005-02
3.5 Friction behavior
The influence of the surface protection on the friction behavior, particularly for parts with metric
ISO thread, shall be determined by testing and matched to the performance characteristics.
The total coefficient of friction of a test batch with surface protection type b140 and with all
surface protection types with additional or integrated lubricant treatment shall be in the range
from 0.09 to 0.15 (except for joining elements with adhesive or locking coating as well as tapping
screws, Powerlock® screws and clamping nuts [all-metal and PA ring]).
3.6 Zinc coatings
Electrolytically deposited or electroplated coatings are not permissible for high-strength steel and/or
standard parts with a tensile strength of Rm > 1,000 MPA and threaded parts with a property
class of � 10.9.
Exceptions are possible for components that are only subjected to pressure.
Zinc flake coatings according to code letter t shall preferably be used.
Only in exceptional cases when electrolytically deposited zinc coating or zinc alloy coating is
absolutely necessary for functional reasons can these coatings be applied with integrated heat
treatment according to DIN 50969. The use of such coatings is limited to tensile strength values of
1,200 MPa for standard parts (see VW 602 50).
Electrolytically zinc-coated parts or zinc alloy coated parts shall be post-treated in passivation
solutions in order to improve corrosion resistance.
Cr(VI)-free passivated zinc coating systems without additional coatings (paint coats) are, apart from
the joining elements, only permissible for use in the passenger compartment.
The appearance of zinc/nickel alloy coatings shall be matched to their immediate environment.
Only transparent passivation treatment is permissible for electrically conducting connections.
Additional sealing of the coating is a further improvement of the corrosion protection of zinc-coated
parts and zinc alloy coated parts respectively.
3.7 Screws, bolts, nuts, threaded parts and shaped parts
The test specifications according to Table 2 apply to the thread-free areas of screws, bolts, nuts
and similar threaded or shaped parts; the next protection class down is applied to the thread and
shank.
The application of the protective layers must not result in the h-position being exceeded in the case
of external threads or the H-position being fallen below in the case of internal threads.
3.8 Commercial surface protection types
Commercial surface protection types can be used for less important applications (e.g. steel wire).
They are not tested for corrosion resistance however. If this kind of protection is sufficient for a
part, the code letter of the method and the digits 010 shall be stated. The description for
commercial coating for example would look like the following: Ofl-x010. Distinction can also be
made between method and finish; e.g. for commercial hot-dip tin coating: Ofl-g020.
The commercial surface protection types, e.g. Ofl-c010 “commercial zinc coating” and Ofl-r010
“commercial electrolytical zinc-alloy coating” must not contain any Cr(VI) compounds.
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VW 137 50: 2005-02
3.9 Parts without surface protection
3.9.1 Joining elements
Parts with the description “bright”, surface protection type “without”, “-” or without any description
shall, as indicated in DIN ISO 8992, be supplied in lightly oiled condition. If in exceptional cases
unoiled parts must be supplied, this must be indicated in the drawing by means of the entry
“not oiled”.
3.9.2 Other parts (e.g. sheets)
QP-A001 applies to parts without surface protection with the description surface protection type
“without” or “bright, oiled”. If in exceptional cases unoiled parts must be supplied, this must
be indicated in the drawing by means of the entry “not oiled”.
3.10 Assignment of surface protection types and codes
The specifications of Table 2 shall apply. Surface protection types represented in bold italics shall
preferably be used for joining elements; surface protection types with a frame are standard surface
protection for components without threads.
Surface protection types in brackets contain Cr(VI) and are not available for new designs.
Table A.3 presents the surface protection types according to VW 137 50 that correspond to the
protection types of VDA1 test sheet 235-104. Table A.4 lists all the invalid protection types that
were included in earlier issues of VW 137 50.
Table 2 – Surface protection type codes
Protection type Codes for protection classes
Code
letter Coating process
Finish/system;
requirements
Post-treatment and
appearance
1
light
3
medium
6
heavy
not oiled b100 - -
passivated b101 - -
oiled, greased,
wax coated b110
2)
- -
silver gray
(for internal applications) b111 - -
yellow glazing, for internal
applications (water-based
paint)
b112 - -
see Footnote 1
manganese phosphated
and oiled b130
10), 22)
- -
b phosphated
1)
thin layer zinc
phosphated;
TL 240
oiled b140 - -
Footnotes: see Page 11
1
VDA = German Association of the Automotive Industry
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VW 137 50: 2005-02
Table 2 (continued)
Protection type Codes for protection classes
Code
letter Coating process
Finish/bath type;
requirements
Post-treatment and
appearance
1
light
3
medium
6
heavy
hot-dip
zinc coated TL 217 without post-treatment - c330 c630
without post-treatment 3) - c310 c610
passivated - c340 c640
passivated and sealed - c341 c641
thick-layer passivated - c342 c642
thick-layer passivated and
sealed - c343 c643
thick-layer passivated, with
lubricant treatment 24) - c347 c647
yellow chromated - (c350)10) (c650)10)
yellow chromated and
sealed - (c351)
10)
(c651)10)
yellow chromated, with
lubricant treatment - (c355)
5),10)
-
Method optional
for high-strength
parts, however
restricted acc.
to Section 3.6;
TL 217
olive chromated 6) - (c360)10) (c660)10)
olive chromated 6) - - (c683) 10)
acid bright zinc
coated; TL 217 olive chromated, with
lubricant treatment 7), 24) - (c385)
10)
(c685)5),10)
light yellow chromated,
sealed - - (c686)
10)
light yellow chromated,
sealed, with lubricant
treatment
7), 24)
- - (c687)10)
passivated and sealed 7) - - c696
c
electrolytically
zinc coated 4)
weakly acidic, for
contact with Mg;
TL 194
passivated and sealed, with
lubricant treatment 7), 24) - - c697
semi-bright nickel
plated
without post-treatment
- e310 8) e610 9)
e
electrolytically
nickel plated bright nickel plated without post-treatment
- e320 8) e620 9)
mirror-bright, with
microcracks - - f620 f electrolytically
chrome-plated
bright chrome-
plated; TL 203
mirror-bright - f350
f650
electrolytically
tin coated bright tin coated without post-treatment g100 g300 g600 g 11)
hot-dip tin coated without post-treatment g120 g320 g620
k electrolytically
copper-plated without post-treatment k110
12)
k310 10),12) -
silvery matte without post-
treatment - - q600
Al coating, TL 243
silvery matte, with lubricant
treatment
24)
- - q605
silvery gloss without post-
treatment - - q610
q
electrolytically
aluminum-alloy
coated
Al/Mg coating,
TL 243 silvery gloss, with lubricant
treatment
24)
- - q615
Footnotes: see Page 11
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VW 1