Surface Coating_VW13750

Group standard VW 13750

Issue 2014-05 Class. No.:50204, 02642

Descriptors:corrosion, anti-rust protection, surface protection (Ofl), metal, surface protection type, code, corrosion

protection

Surface Protection for Metal Parts

Surface Protection Types, Codes

Previous issues

VW 13750: 1953-06, 1954-07, 1956-10, 1958-04, 1959-03, 1959-06, 1963-03, 1963-05, 1966-06, 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, 2005-02, 2008-01, 2008-06

Changes

The following changes have been made to VW 13750: 2008-06:

–Section 2.2 Description example redefined

–Section 3.1 VW 11628 added

–Section 3.5 VDA 235-203 superseded by VW 01131-1 and VW 01131-2

–Section 3.6 2nd paragraph "Exceptions" changed

–Section 3.7 Wording changed in terms of test requirement

–Section 3.9.1 changed, Ofl-a102 added

–Section 3.10 Table 2 "Codes for surface protection types" updated:

–Surface protection types containing Cr(VI) removed; for an overview, see new section A.2

–Ofl-a102 "oil film dependent on manufacturing and/or material conditions" added

–Supplements to surface protection type b; b130 removed and added to VW 13750, supple‐ment 1

–Ofl-113 added

–Reference to heat treatment added as a footnote for Ofl-b140 and Ofl-b149

–Supplement in "Post-treatment and appearance" column for surface protection type c: "silver-colored" and "to slightly iridescent blue" and "iridescent color", respectively

Always use the latest version of this standard.

Page 1 of 21 This electronically generated standard is authentic and valid without signature.

The English translation is believed to be accurate. In case of discrepancies, the German version is alone authoritative and controlling.

All rights reserved. No part of this document may be provided to third parties or reproduced without the prior consent of one of the Volkswagen Group’s Standards departments.

? Volkswagen Aktiengesellschaft VWNORM-2012-05r

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–Supplement in "Post-treatment and appearance" column for surface protection type e, f, and g: "silver-colored"

–Ofl-k310 removed and added to VW 13750, supplement 1

–Ofl-q600 and Ofl-q605 as per TL 243 removed and added to VW 13750, supplement 1

–Description of surface protection types and Ofl-r647 and Ofl-r648 from TL 244 added –"Post-treatment and appearance" column changed for surface protection type r: "with Al-pig‐mented top coat" and "silver-colored" added

–Ofl-s617 as per TL 196 removed and added to VW 13750, supplement 1

–Description of Ofl-t330 and Ofl-t630 as per TL 233 changed

–Ofl-t615 deleted as "standard surface protection for nuts with non-metallic clamping" as per TL 245

–Ofl-t660 and Ofl-t667 as per TL 180 added

–Ofl-u620 as per TL 184 added

–Supplement in "Post-treatment and appearance" column for surface protection type v: "color‐less passivation plus post-dip solution" and "gray"; footnote expanded

–Ofl-w660 and Ofl-w670 as per TL 212 "not permissible for new designs" removed; footnote for Ofl-w660 matte added and description of surface protection type w changed

–Ofl-x130 deleted and description of the coatings as per TL 260 revised

–Ofl-x340 as per TL 256 added

–Ofl-x590 as per TL 178 added

–Ofl-x607 as per VW 60469 added

–Ofl-x635 as per TL 262 added

–Ofl-x640 as per TL 227 added

–Supplement in "Post-treatment and appearance" column for surface protection type z: "silver-colored"

–Footnotes changed from numbers to letters and comparison to previous issue added as an overview in section A.3

–Changes to footnotes must be taken from section A.3

–Appendix A changed:

–Previous section A.1 list "Comparison of "not for new design"/"for new design" of surface pro‐tection types containing Cr(VI)" (includes surface protection types containing Cr(VI)) removed –Previous section A.2 list "Surface protection types without codes" removed

–List "Surface protection types as per VDA 235-104 and VW 13750" became section A.1; table redefined

–Section A.2 "Deleted surface protection types containing Cr(VI)" added

–Section A.3 "Revision record for footnotes" added

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Contents

Page

Scope .........................................................................................................................3Description .................................................................................................................3Code composition ......................................................................................................3Description example ...................................................................................................4Requirements .............................................................................................................4General requirements ................................................................................................4Specifications in drawings ..........................................................................................5Weldability (6)

Agents impairing wetting ability ..................................................................................6Friction behavior .........................................................................................................6Zinc and zinc alloy coatings .......................................................................................6Screws, bolts, nuts, threaded parts and molded parts ...............................................6Commercial surface protection types .........................................................................6Parts without surface protection .................................................................................7Fasteners with metric ISO threads .............................................................................7Other parts .................................................................................................................7Assignment of surface protection types and codes ....................................................7Applicable documents ..............................................................................................14..................................................................................................................................17Surface protection types as per VDA 235-104 and VW 13750 ................................17Deleted surface protection types containing Cr(VI) ..................................................18Revision record for footnotes .. (19)

122.12.233.13.23.33.43.53.63.73.83.93.9.13.9.23.104

Appendix A A.1A.2A.3Scope

This standard applies to the identification of general surface protection types of vehicle parts and units in drawings and technical documentation.

VW 13750, supplement 1 "Surface Protection for Metal Parts; Invalid Ofl Designations" lists all in‐valid surface protection types that were included in earlier issues of VW 13750.Description Code composition

See figure 1. The abbreviation for surface protection ('Ofl-' from the German word for 'surface') is followed by a 4-character code from table 2.

Figure 1

1

2 2.1

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Description example

For surface protection: electrolytically zinc-alloy-plated, heavy protection, silver-colored to slightly iridescent blue, passivated, transparent sealed and treated with lubricant, as per TL 244.

VW 13750 – Ofl-r645

Requirements General requirements

The vehicle parts and units are classified according to their corrosion load and assigned to a pro‐tection class with grade (as per table 1) by the appropriate Design Engineering department in agreement with the Volkswagen AG Laboratory (GQL-M/1) and/or the Audi AG Laboratory (I/GQ-31).

The restrictions as per VW 60361 must be observed for mechanical fasteners.

The following standards apply to thread dimensions before surface treatment: VW 11610,

VW 11614, VW 11624, VW 11625, and VW 11627. The following standards apply to thread dimen‐sions after surface treatment: VW 11611, VW 11615, and VW 11628.Avoidance of hazardous substances as per VW 91101.

All-metal clamping nuts must always be treated with additional or integrated lubricants. Nuts with non-metallic clamping may be treated with lubricant in order to ensure the defined functional char‐acteristics. The lubricant must be neither hazardous to the user nor emit an unpleasant odor during the fastening process. It must also be suitable for automatic tightening. The functional characteris‐tics of nuts treated with protective coating and/or lubricants must not deteriorate within a storage period of 6 months in weather-sheltered rooms. The storage temperature must be between -5 °C and +40 °C.

Fasteners made of stainless or high-temperature resistant materials may require an additional lu‐bricant treatment in order to fulfill the requirements of VW 01129.

2.2 3

3.1

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Table 1 – Classification of vehicle parts

Specifications in drawings

If a certain surface protection is required for the entire part or for several parts in the ASSY, the code must be entered in the "Surface protection" title block; e.g. Ofl-t650 (see also VW 01058). If several surface protection types are approved for elective application, then the codes of all ap‐proved treatments must be indicated,e.g., Ofl-r673/x630.

If only partial protection is applied to a workpiece, "see drawing" must be entered in the "Surface protection" title block; the affected area on the part must be marked with a wide dash-dot line (figure 2) and the code indicated with a datum line.

If only a small area on the part has no surface protection, then the unprotected area must be marked (figure 3). In this case, "see drawing" must be entered in the "Surface protection" title block.

Figure 2Figure 3

If different surface treatments are specified on a single part, "see drawing" must be entered in the "Surface protection" title block. The affected areas on the part must be clearly delineated.

If parts from one ASSY are coated individually (one or several different surface treatments), then "see drawing" must be entered in the "Surface protection" title block of the assembly drawing. The surface treatments will then be listed individually on a parts-related basis in the respective drawing.

3.2

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Weldability

If parts with surface protection will be welded to one another or to other metal parts, then the parts must be tested for weldability. Provision must be made for Ofl-c340 as the standard surface protec‐tion type in car body manufacture (e.g., for weld nuts).Agents impairing wetting ability

Lubricants and slushing oils must be free of silicone oils and other agents that significantly impair wetting ability.Friction behavior

The influence of the surface protection on the friction behavior, particularly for parts with metric ISO threads, must be determined by tests and matched to the performance characteristics (see VW 01131-1 and VW 01131-2).Zinc and zinc alloy coatings

Electrodeposited/galvanized coatings are not permissible for high-strength steel and/or standard parts with a tensile strength of R m > 1 000 MPa and threaded parts with a property class ≥10.9.The use of zinc flake coatings as per code letter t is preferred.

Exceptions are possible for Zn/Ni coatings as per TL 244 and TL 196 for steel parts with a tensile strength of 1 000-1 200 MPa (max. Vickers hardness 370 HV), but also for components that are only loaded with compression stresses arising during installation, e.g., for nuts with a property class ≤10. The same applies to PT screws as per VW 60358 and self-tapping screws as per DIN EN ISO 1478. In all mentioned use cases, a heat treatment as per DIN EN ISO 4042 is re‐quired.

Electrolytically zinc-plated or electrolytically zinc-alloy-plated parts may be post-treated in passiva‐tion solutions in order to improve corrosion resistance. Yellowish passivation treatment corre‐sponding to the appearance of yellow chromating with Cr(VI) is not permissible.

Electroplated zinc systems without additional coatings (e.g., paintwork or sealants) are only per‐missible for the vehicle interior area.

The appearance of zinc/nickel alloy coatings must be matched to their immediate environment. On‐ly transparent passivation is permissible for electrically conducting connections.Screws, bolts, nuts, threaded parts and molded parts

For screws, bolts, nuts, and similar threaded parts and molded parts, more stringent test require‐ments apply to the thread-free areas and also to the thread profile and shank. Details in terms of the test requirements are described in the respective standards.

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 not being reached in the case of internal https://www.sodocs.net/doc/9218981828.html,mercial surface protection types

Commercial surface protection types may be used for less important applications (e.g., steel wire).However, they are not subject to corrosion resistance testing. If such protection is sufficient for a

3.3 3.4

3.5

3.6

3.7

3.8

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given part, only the code letter of the respective procedure and the numbers 010 must be indica‐ted. The designation then reads, e.g., for commercial paintwork: Ofl-x010. A distinction can also be made between procedure and finish; e.g., for commercial hot-dip tinning:Ofl-g020.

The commercial surface protection types, e.g. Ofl-c010 "commercial zinc coating" and Ofl-r010"commercial electroplated zinc alloy coating" must not contain any Cr(VI) compounds.

The avoidance of hazardous substances as per VW 91101 also applies to commercial surface pro‐tection types.Parts without surface protection Fasteners with metric ISO threads

The following surface protection types are used here:Ofl-a100:corresponds to "not oiled".

Ofl-a101:corresponds to "lightly oiled" as per DIN ISO 8992.

Ofl-a102:oil film dependent on manufacturing and/or material conditions permissible.

Other parts

For parts without surface protection and with surface protection designation "without" or "plain,oiled", QP A001 applies. If, in exceptional cases, unoiled parts must be supplied, this must be indi‐cated in the drawing by means of the entry "not oiled". The use of surface protection types intro‐duced for fasteners is permissible.Assignment of surface protection types and codes

The specifications in table 2apply. Surface protection types with codes shown in italics and bold are preferred for fasteners; surface protection types with codes with gray backgrounds are stand‐ard surface protection for components without threads.

Table A.1 lists the surface protection types as per VW 13750 that correspond to the surface protec‐tion types as per VDA 235-104.

Table 2 – Codes for surface protection types

3.9 3.9.1

3.9.2

3.10

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a)No base metal corrosion after 4 hours in the condensation test atmosphere with constant humidity as per DIN EN ISO 6270-2.

b)After phosphating, steel parts with tensile strength values greater than 1 200 MPa may be subjected to appropriate heat treatment

up to a max. of 200 °C to avoid brittle fractures induced by hydrogen (DIN EN ISO 9717).

In addition to the specifications as per table 2, the following periods of time must be taken into account for the individual protection classes when performing the salt spray test NSS as per DIN EN ISO 9227:

Ofl-b100, Ofl-b101 2 hours, without base metal corrosion,

Ofl-b110 6 hours, without base metal corrosion,

Ofl-b111, Ofl-b11348 hours, without base metal corrosion.

NOTE 1: Ofl-b111 = Ofl-b100 + (2 to 4) μm zinc flake coating; light abrasion, high susceptibility to soiling of other parts in the event of contact.

NOTE 2: Ofl-b113 = Ofl-b149 + (2 to 4) μm zinc flake coating + (2 to 3) μm top coat (GZ); less abrasion than for Ofl-b111.

c)Suitable for fasteners used in the body-in-white and for fasteners with adhesive coatings as per DIN 267-27, locking coatings as per

DIN 267-28, and sealing coatings as per TL 195.

d)For threaded parts, only oil or oil emulsion permissible.

e)Immediately after surface treatment, steel parts that are subject to tensile stress and have tensile strength values greater than

1 000 MPa must be subjected to an appropriate heat treatment to avoid brittle fractures induced by hydrogen. This must be verified

by means of the bracing test as per DIN 50969-1 and DIN 50969-2.

f)For parts to be painted in-house.

g)Electrolytically zinc-plated parts with Cr(VI)-free passivation must not appear yellowish in order to be able to distinguish the parts

from the yellow chromating containing Cr(VI) often used in the past.

h)Metric ISO threaded parts must be treated with lubricant as per TL 52132.

i)Preferably for steel parts in assemblies with magnesium in order to avoid bimetallic corrosion.

j)Ofl-e310, Ofl-e320 = coating thickness > 10 μm,

Ofl-e610, Ofl-e620 = coating thickness > 20 μm.

k)Requirements in:

Protection class 1 = DIN 50965–Fe/Sn4, coating thickness > 4 μm, DIN 50965–Cu/Sn4 > 4 μm;

Protection class 3 = DIN 50965–Fe/Sn4, coating thickness > 4 μm, DIN 50965–Cu/Sn4 > 8 μm;

Protection class 6 = DIN 50965–Fe/Sn4, coating thickness > 4 μm, DIN 50965–Cu/Sn4 > 15 μm.

l)For steel parts in assemblies with magnesium in order to avoid bimetallic corrosion, but only when electrical conductivity is required. m)Ofl-k110 = coating thickness (3 + 3) μm.

n)Preferred surface protection type for self-tapping screws and PT screws.

o)Metric ISO threaded parts must be treated with lubricant as per TL 52165.

p)Contains PTFE, not suitable for adhesive bonds.

q)No change to surface after 120 h of salt spray test NSS as per DIN EN ISO 9227 (e.g., no zinc corrosion of zinc die-castings).

r)No change to surface after 240 h of salt spray test NSS as per DIN EN ISO 9227 (e.g., no zinc corrosion of zinc die-castings; this is

a passivation layer plus post-dip solution containing phosphate, e.g., by Hillebrand with the designation "Premium Diecast Finish"). s)In order to create a special surface structure, a special pickling stage, e.g., EO/E6, is required.

t)Color specification as per drawing; otherwise, black.

u)Requirements also apply to dip-primed body components.

v)Instead of single-layer liquid paint, KTL may be required; if this is the case, the suffix "KTL" must be added to the code.

w)Sn: (70 ± 12)%, Balance: Zn. Coating thickness ≥5 μm. Without base metal corrosion after 360 h of salt spray test NSS as per DIN EN ISO 9227.

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Applicable documents

4

The following documents cited in this standard are necessary to its application.

Some of the cited documents are translations from the German original. The translations of Ger‐man terms in such documents may differ from those used in this standard, resulting in terminologi‐cal inconsistency.

Standards whose titles are given in German may be available only in German. Editions in other languages may be available from the institution issuing the standard.

QP A001Prelube, Hot Melt, Blank Washing Oil, Drawing Compound, Slushing Oil

(General); Quality Requirements

TL 153Zinc/Iron Coatings; Surface Protection Requirements

TL 178Kathodische Elektrotauchlackierung (KTL) von Karosserieau?enhauttei‐

len aus Aluminiumhalbzeug; Oberfl?chenschutzanforderungen

TL 180Non-Electrolytically Applied Zinc Flake Coatings with Black Top Coat;

Surface Protection Requirements

TL 182Inorganic Protective Coating on Aluminum Parts; Surface Protection Re‐

quirements

TL 184Zinc Thermal Diffusion Layers(Zn-ThD Layers); Surface Protection Re‐

quirements

TL 194Coating for Joining Elements when in Contact with Magnesium; Surface

Protection Requirements

TL 195Mechanical Joining Elements; Steel Metric Bolts with Sealing All-Around

Coating (KLD); Material Requirements

TL 196Duplex Coating Systems for Small Parts and Bulk Parts; Surface Protec‐

tion Requirements

TL 203Decorative Chrome-Plating (Ni-Cr Coatings) on Metallic Components;

Surface Protection Requirements

TL 212Oxide Coatings on Aluminum Parts; Surface Protection Requirements TL 214Zinc Dust Paint Coating; Surface Protection Requirements

TL 217Zinc Coatings; Surface Protection Requirements

TL 218Body Color Multicoat Paint on Metallic Exterior Body Components; Re‐

quirements

TL 227Single-Layer Paint of Zinc-Coated Metal Surfaces; Surface Protection

Requirements

TL 233Non-Electrolytically Applied Zinc Flake Coatings with Top Coat; Surface

Protection Requirements

TL 235Manganese Phosphated Surfaces; Requirements

TL 240Thin-Layer Zinc Phosphating; Surface Protection Requirements

TL 244Zinc/Nickel Alloy Coatings; Surface Protection Requirements

TL 245Non-Electrolytically Applied Zinc Flake Coatings; Surface Protection Re‐

quirements

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TL 256Powder Paint on Metal Surfaces; Surface Protection Requirements

TL 260Paint Coating of Metal Surfaces; Requirements for Surface Protection TL 262Paint Finish of Chassis Parts; Corrosion Protection

TL 52132Lubricant for Threaded Fasteners with Electrolytically Applied Coatings

or those of Stainless Steel; Requirements

TL 52165Lubricant (greenish) for Threaded Fasteners; Material Requirements VW 01058Engineering Drawings; Lettering

VW 01110-1Threaded Joints; Design and Assembly Specifications

VW 01129Limit Values for Coefficients of Friction; Mechanical Fasteners with Met‐

ric ISO Threads

VW 01131-1Determination of Coefficients of Friction; Practice- and Mounting-Orien‐

ted Testing

VW 01131-2Determination of Coefficients of Friction; Release of New Surface Coat‐

ing Systems

VW 11610Metric ISO Thread; Limit Dimensions for Medium Tolerance Class; Ex‐

ternal Threads 6g / Internal Threads 6H

VW 11611Metric ISO Thread; Limit Dimensions with Protective Coating for Medium

Tolerance Class; External Threads 6gh / Internal Threads 6H

VW 11614Metric ISO Thread; Limit Dimensions for Coarse Tolerance Class, Exter‐

nal 8g, Internal 7H

VW 11615Metric ISO Thread; Limit Dimensions with Protective Coating for Coarse

Tolerance Class (8g/7H)

VW 11624Metric ISO Thread; Limit Dimensions for Tolerance Class 6f/6G

VW 11625Metric ISO Threads; Limit Dimensions for Tolerance Class 8f/7G; Exter‐

nal Thread 8f, Internal Thread 7G

VW 11627Metric ISO Thread; Limit Dimensions for Medium Tolerance Class; Ex‐

ternal thread 6e

VW 11628Metric ISO Thread; Limit Dimensions for External Threads, Tolerance

Class 6g with Galvanic Protective Coating

Surface Protection for Metal Parts; Invalid Ofl Designations

VW 13750,

supplement 1

VW 60358Self-Tapping Screws for Thermoplastics; Dimensions, Requirements,

Tests

VW 60361Mechanical Joining Elements; Parts Reduction; General Guidelines

VW 60469Aluminum Alloy AL9 for Screws and Bolts; Mechanical Properties

VW 91101Environmental Standard for Vehicles; Vehicle Parts, Materials, Operat‐

ing Fluids; Avoidance of Hazardous Substances

DIN 267-27Fasteners - Part 27: Steel screws, bolts and studs with adhesive coating,

Technical specifications

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DIN 267-28Fasteners - Part 28: Steel screws, bolts and studs with locking coating,

Technical specifications

DIN 50938Black oxide coatings on iron or steel - Requirements and test methods DIN 50965Electroplated coatings - Tin-coatings on iron steel and on copper and

copper alloys

DIN 50969-1Prevention of hydrogen-induced brittle fracture of high-strength steel

building elements - Part 1: Advice on the prevention

DIN 50969-2Prevention of hydrogen-induced brittle fracture of high-strength steel

building elements - Part 2: Test methods

DIN EN ISO 1478Tapping screw thread

DIN EN ISO 4042Fasteners - Electroplated coatings

DIN EN ISO 6270-2Paints and varnishes - Determination of resistance to humidity - Part 2:

Procedure for exposing test specimens in condensation-water atmos‐

pheres

DIN EN ISO 9227Corrosion tests in artificial atmospheres - Salt spray tests

DIN EN ISO 9717Metallic and other inorganic coatings - Phosphate conversion coating of

metals

DIN ISO 8992Fasteners - General requirements for bolts, screws, studs and nuts VDA 235-104Cr(VI)-free surface protection for mechanical fasteners with metric

thread

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Surface protection types as per VDA 235-104 and VW 13750

Table A.1 compares the Cr(VI)-free surface protection types for fasteners with metric ISO threads described in VDA 235-104 with comparable surface protection types from VW 13750.

Table A.1

Type of surface protection layer

Description

as per VDA 235-104as per VW 13750

Thin-layer phosphating VDA 235-104.10Ofl-b140 Electroplated zinc coating,

transparent passivated

VDA 235-104.20Ofl-c347 Electroplated

zinc alloy coating,

transparent passivated

VDA 235-104.25Ofl-r645 Electroplated

zinc alloy coating, black passivated VDA 235-104.30

Ofl-r302 or Ofl-r677, no direct as‐

signment possible

Zink flake coating,

silver-colored

VDA 235-104.40Ofl-t610 Zinc flake coating

with top coat, silver-colored

VDA 235-104.42Ofl-t647

Zinc flake coating with top coat, black VDA 235-104.50Ofl-t667, Ofl-t630

Appendix A (informative) A.1

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Deleted surface protection types containing Cr(VI)

For an overview of the deleted surface protection types containing Cr(VI), see table A.2.

Table A.2

Code letter c:Code letter r:Code letter t:Code letter v:

(Ofl-c350) (Ofl-c351) (Ofl-c355) (Ofl-c360) (Ofl-c385) (Ofl-c650) (Ofl-c651) (Ofl-c660) (Ofl-c683) (Ofl-c685) (Ofl-c686) (Ofl-c687)(Ofl-r600)

(Ofl-r605)

(Ofl-r610)

(Ofl-r620)

(Ofl-r630)

(Ofl-r650)

(Ofl-r660)

(Ofl-r665)

(Ofl-r670)

(Ofl-r675)

(Ofl-t300)

(Ofl-t320)

(Ofl-t345)

(Ofl-t600)

(Ofl-t620)

(Ofl-t645)

(Ofl-v110)

A.2

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A.3

The following changes to the footnotes have been made as compared to the previous issue

VW 13750: 2008-06; see table A.3:

–Footnote numbering changed from numbers to letters and

–text changes have gray backgrounds.

Table A.3

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