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Company Standard

Technical Cleanless Articles –Bought-in Parts

(external use) CS 0135 / Revision 02 / Author: COQ-Sku

© Thomas Magnete GmbH. All rights reserved. Strictly confidential. of 19

1. Area of application

This company standard applies to all the companies in the Thomas Group. It is to be understood as the top-

level, supplementary document for Technical Cleanliness. This company standard can be used as a basis for

creating user requirement specifications for bought-in parts and for the formulation of quality

characteristics lists of Thomas magnets GmbH.

2. Description

This company standard how to address the topic of Technical Cleanliness and Product Cleanliness. This

organizational instruction defines cleanliness measures for the various products, product groups,

components and assemblies. It also describes behavior with and handling of cleanliness-critical products.

This company standard or extracts taken from it shall be applied to all products and processes of Thomas

magnets GmbH that are applicable to product realization as defined by customer requirements. This

applies both to the suppliers of Thomas magnets GmbH and to the supporting processes.

This company standard instruction was created for application to products of Thomas magnets GmbH. The

provisions and procedures described are binding for general availability as soon as reference is made to this

company standard in drawings, user requirement specifications, component-related QA agreement or in

any other technical specifications using the formats specified here. Deviations from specifications in this

organizational instruction are equivalent to a drawing deviation and must systematically be treated with

targeted decisions, by rework using a cleaning operation for example.

The present company standard shall enter into force on the date of its approval for components,

production facilities and processes for which technical cleanliness specifications have been defined with

reference to this organizational instruction.

2.1 Cited Standards

ISO 16232

VDA 19.1

VDA 19.2

2.2 Terms and Definitions

P-FMEA = Process Failure Mode and Effects Analysis

PCP = Production Control Plan

PFC = Process Flow Chart

PSW = Part Submission Warrant

Cleanliness level = VDA 19.2 classification of various cleanliness levels. These reflect the

necessary measures and specifications to achieve a cleanliness level

Thomas cleanliness class = Thomas cleanliness classes represent cleanliness relevance in the

product. Classification triggers measures and specifications, matched

to the particular cleanliness level.

Component cleanliness code = Reflects the degree of residual soiling, divided into size and number.

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2.3 Concept

2.3.1 General

To be able to effectively implement the requirements imposed here, it is necessary to think and

act across all levels, divisions and processes.

Each individual person, from the buyer to the production employee, must be aware of the

importance of Technical Cleanliness.

Rules, processes and procedures that must be integrated at the earliest possible stage of product

realization will be defined and optimized in the following sections of this document.

2.3.2 Component Cleanliness Code

Indication by Thomas magnets GmbH is strictly based on VDA 19.

Thomas magnets GmbH opts to indicate with reference to a component (CCC=N) by default.

This means that both the formulation of the Component Cleanliness Code internally (cleanliness

analyses, documentation, drawing, etc.) and externally (drawing, specifications, customer and

supplier communication, etc.) refers to a component by default and not to the area.

Consequently, indication uses size classes, supplemented by the recoded number of particles.

Size classes as per VDA 19 and ISO 16232:

The Component Cleanliness Code can refer to various criteria.

/b = Component Cleanliness / analysis value refers to particle width.

/I = Component cleanliness / analysis value refers to particle length.

If a criterion is not indicated explicitly, particle size refers to length.

Example: CCC/b = N (B586/C180/D38/E3/F1)

Indication of Component Cleanliness Code CCC with reference to component N

Example: CCC = N (B7647/C2934/D1016/E174/F19/G6/H5/I1/J-K0)

Reference

N = component

Size class as per Table 1

Number of particles, recoded

5≤x

15µm

15≤x

<25µm

25≤x

<50µm

50≤x

<100µm

100≤x

<150µm

150≤x

<200µm

200≤x

<400µm

400≤x

<600µm

600≤x

>1000µm >1000µm

B C D E F G H I J K

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In exceptional cases indication of the Component Cleanliness Code CCC may refer to

volume V or area A

Example: CCC = A (B20/C16/D16/E12/F12/G-J8)

Reference

V = volume; A = area

Size class as per Table 1 (Section 2.2)

Concentration class as per Table 2 (Section 2.2)

Combined size classes

Example 2; CCC = A(B18/C-E16/F-I11/J-K2) (per 1000cm²)

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Table 1 – Size classes for particle counting Table 2 – Definition of the cleanliness level of a component

Größenklasse (Size Class)

Größe X (m) Sauberkeitsklasse (Cleanliness)

Anzahl der Partikel (pro 1000 cm2 oder 100 cm3)

B 5 ≤ x < 15 mehr als bis einschließlich

C 15 ≤ x < 25 24 8 x 106 16 x 106

D 25 ≤ x < 50 23 4 x 106 8 x 106

E 50 ≤ x < 100 22 2 x 106 4 x 106

F 100 ≤ x < 150 21 1 x 106 2 x 106

G 150 ≤ x < 200 20 500 x 10³ 1 x 106

H 200 ≤ x < 400 19 250 x 10³ 500 x 10³

I 400 ≤ x < 600 18 130 x 10³ 250 x 10³

J 600 ≤ x < 1000 17 64 x 10³ 130 x 10³

K 1000 ≤ x 16 32 x 10³ 64 x 10³

15 16 x 10³ 32 x 10³

14 8 x 10³ 16 x 10³

13 4 x 10³ 8 x 10³

12 2 x 10³ 4 x 10³

11 1 x 10³ 2 x 10³

10 500 1 x 10³

9 250 500

8 130 250

7 64 130

6 32 64

5 16 32

4 8 16

3 4 8

2 2 4

1 1 2

0 0 1

00 - 0

Quelle VDA Band19

Note 1 The size of the largest particle (found or allowable) can be expresses individually, Independent of the nominal size classes

specified above (see clause 8)

Note 2 According to individual requirements, size ranges may be combined and left out.

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2.3.3 Thomas Cleanliness Classes

Thomas Cleanliness Classes Degree of cleanliness

A Highest component standard Ultrafine cleanliness

B High component standard Fine cleanliness

C Medium component standard Normal cleanliness

D Standard component standard Coarse cleanliness

E Undefined component standard Undefined particulate cleanliness

Every product must be recorded and assigned to a Cleanliness Class. Thomas cleanliness classes

are used as a basis for specifying

Measuring intervals

Test method and testing equipment

Cleaning specifications for production equipment

Thomas Cleanliness

Classes

Test method at

supplier's Supplier's test intervals

Cleaning specifications

for production

equipment

Packaging

A Highest component

standard

Automatic particle

counting system:

1 x per shipping unit or

per production batch

but at least once a

week.

3 components from

different packing units

in one group analysis

Coordination of

cleaning by external

contractor for all

systems (2 x per year)

No wood or cardboard,

plastic, with cover,

delivery preferably as

positioned parts in

trays,

heat-sealed in plastic

film, in special load

container (adapted to

workpiece geometry,

with plastic film hood)

B High component

standard

Automatic particle

counting system

1 x per shipping unit or

per production batch

but at least once every

two weeks.

3 components from



Coordination of


contractor for all


No wood,


delivery in trays; special

load container closed

(e.g. adapted to

workpiece geometry,

with plastic film hood)

C Medium component

standard

Monitoring: Twice a

year

3 components from



Coordination of


contractor for all


No wood,


load container closed

(e.g. Schäfer box with

lid, pallet closed on all

sides)

D Standard

component standard

Coordination of


contractor for all


E User device

standard for use on

user device drawings

Customer requirements

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2.3.1 Drawing

Cleanliness requirements must be integrated into the drawings. Here the product cleanliness is

defined by indicating the Thomas Cleanliness Class and the Component Cleanliness Code,

According to the requirements of this company standard, Section 2.3.2, the Component

Cleanliness Code shall refer to the individual component (CCC = N ).

The following formulation shall be used on drawings of articles (bought-in parts). The Component

Cleanliness Code CCC defined here in the formulation is to be understood as an example.

Product cleanliness as delivered:

Technical cleanliness as per Thomas CS 0135

CCC = N(B462/C177D61/E11/F1/G0/H0/I0/J0/K0)

2.4 Preliminary Planning

In line with our concept of integrating Technical Cleanliness into the processes as early as possible,

the issue shall be integrated into the APQP process.

Specifically, this means that in the following documents, procedures and processes the issue of

Technical Cleanliness must be addressed with the supplier.

2.4.1 Customer Specifications

Supplier specifications shall be discussed with regard to cleanliness requirements and be applied

to the list of quality features (performance specification).

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Thomas magnets GmbH must formulate and communicate specifications with regard to VDA 19

and Section 2.3 of this company standard

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2.4.2 Contract Review

In line with the APQP process, the supplier shall issue confirmation of manufacturability. This

confirmation of manufacturability must also explicitly refer to the fulfilment of cleanliness

requirements. Contractual items (limits, escalation management and complaints handling, tests,

test location and time) that address the issue of Technical Cleanliness must be agreed with the CTQ

department.

2.4.3 Design FMEA

If the supplier is responsible for design, a design FMEA must be performed. A design FMEA

constitutes an important tool for influencing the cleanliness of the product. In it the influence of

particles on the design must be described and evaluated by a cross-divisional team.

2.4.4 Facilities and Tools

In this context the equipment, means of production and facilities for manufacturing products with

increased standards of Technical Cleanliness must be checked for suitability.

2.4.5 Test and Testing Equipment

A check must be performed to establish whether the test methods and testing equipment are

suitable for analyzing cleanliness. Potential equipment and methods are discussed in Section 2.7.

Any deviations from the test methods and testing equipment must be approved by the CTQ

department at Thomas magnets GmbH.

2.4.6 Technical Approval of A-Article (Design Freeze Drawings / Specifications)

In all necessary documents, but at least on the drawing, the standards of Technical Cleanliness

must be defined by the time of Technical Approval of the A-articles at the latest. They shall be

formulated clearly and unambiguously, based on VDA 19 and Section 2.3.3 – 2.4 of this

organizational instruction.

2.4.7 Process Flow Chart and Production Layout

The specific processes for cleanliness must be indicated on the process flow chart. Since this flow

chart is regarded as a basis of the P-FMEA and the PCP, this step is of fundamental importance.

Thomas magnets GmbH must check the PFC for specific cleanliness processes.

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2.4.8 Process FMEA

All cleanliness-relevant points arising from the Design FMEA and the process flow chart constitute

the basis of detailed analysis in the P-FMEA. Furthermore, the various process steps of product

realization (from goods receiving and logistics to packaging) must be analyzed for potential risks of

soiling and contamination, and measures must be taken to reduce the risk.

The supplier must perform and analyze its P-FMEA with regard to cleanliness.

2.4.9 Process Instructions

In the documents concerning manufacture of the product all the instructions (Operating

Procedures, Process Procedures, Inspection and Test Plans, Maintenance Plans, etc.) must be

extended to include the topic of Technical Cleanliness if necessary.

2.4.10 Logistics Concept / Packaging Materials

The logistics concept is crucial to compliance with cleanliness requirements. The concept must be

developed taking into account the avoidance of contamination, selection of suitable packaging,

primary and secondary packaging, transport routes, method and duration of storage in accordance

with the specifications of Section 2.5.5

2.4.11 PPAP-Documents

Documented Technical Cleanliness must also be specified in the PPAP documents. A record must

be kept of the fact that the cleanliness requirements have been met. A PSW must not be issued

without objective evidence of the fulfilment of the cleanliness requirements.

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2.5 Suppliers

2.5.1 Selection of Suppliers

Suppliers shall be selected according to the rules issued by Thomas magnets GmbH.

However, care must be taken to ensure that the requirements regarding Technical Cleanliness can

be met by subcontractors. This also includes the requirements specified in this standard for

packaging materials, cleanliness, possible analysis and transport.

2.5.2 Integration of Suppliers into the Cleanliness Concept

To ensure seamless, plannable component cleanliness, the subcontractor shall be notified of the

various measures concerning Technical Cleanliness. In an early conceptual phase the various

measures (e.g. cleaning, transport, packaging materials, etc.) must be agreed with the

subcontractor and implemented. The points discussed in the APQP process over which the

subcontractor has an influence should serve as a guide and as a basis for constructive talks. The TS

16949 requirement that all the specifications be passed on to subcontractors applies here too.

2.5.3 Requirements for the Supplier

To define requirements for all suppliers and products is extremely difficult and not expedient. The

specifications should be determined individually for the particular project/product but should at

least meet the requirements derived from the Thomas Cleanliness Classes.

The specifications to be defined shall comprise the following point:

Measuring intervals

Number of samples (number of components)

Cleaning specifications

Production site

Packaging

Testing equipment

2.5.4 Support / Supplier Development

To successfully realize the concept and implement Technical Cleanliness as an important

requirement, Thomas magnets GmbH gives the suppliers an assurance that they will receive

support in the form of:

Cleanliness audits

Know-how transfer

Exchange of experience

Training sessions / audits

Checklists

Recommendations concerning suitable analysis equipment

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2.5.5 Packaging

2.5.5.1 Determining the Packaging

The definition of packaging is derived from multiple factors:

Thomas Cleanliness Class (Thomas`internal one)

Function of the component

Material

No supplier article may ever be packed directly in a cardboard bos (a protective enclosure is

required, e.g. polythene bag / tray / blister pack). In addition, the large load container must not be

made of wood and must be surrounded by secondary packaging (stretch-wrap film).

The decision whether an article must be delivered as bulk cargo, layered cargo or positioned cargo

shall be based on the following decision-making chart:

2.5.5.2 Use of Packaging

The packaging provided by Thomas magnets GmbH (small load container, tray, etc.) shall only

serve as packaging for products that are delivered to Thomas magnets GmbH. Internal use is

prohibited.

It is enclosed by secondary packaging and must be stored until use in such a way that the

packaging is protected against becoming soiled again.

Component

Components with minimal

surface sensitivity (very light,

round, hardened)

or solely with

inner functional surfaces

Components that must not be

poured as bulk owing to their

mass, size and surface.

Components with moderate

surface sensitivity

or with inner

functional surfaces

Components with sensitive

outer surfaces

Bulk cargo Layered cargo Positioned cargo

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2.5.5.3 Cleanliness of Pool Packaging

If the packaging was cleaned before delivery to the supplier, the supplier must check the

cleanliness of the packaging. The packaging (e.g. small load container, tray) shall be subjected to

visual inspection before it is filled with Thomas magnets GmbH goods. If the cleanliness of the

packaging is not guaranteed due to soiling (wood shavings, swarf, fluff, etc.), such packaging must

be not be used. At the same time the soiling must be documented and reported to Thomas

magnets GmbH.

2.6 Controlling, Campaigns and Measures

2.6.1 Audits

The scope of audits at suppliers` premises shall include verification of Technical Cleanliness. In the

event of any deviations, measures must be defined and their effectiveness checked.

When conducting Internal Audits the supplier undertakes to extend them to include the issue of

Technical Cleanliness.

2.6.2 Monitoring

As part of the in-process inspections the supplier must check the cleanliness of articles by means

of a residual dirt analysis (see Section 2.7). The results must be documented and sent to Thomas

magnets GmbH along with the relevant deliveries (can also be performed electronically). The test

intervals shall accompany production and be based on the production batch. If the production

batches are too large so that in-process monitoring does not allow any representative conclusion

to be made regarding the soiling of the article, the test interval must be shortened. The analysis

interval should be selected according to the production volume, the aim being to make reliable

statements concerning product cleanliness. The test intervals must be clearly formulated and be

integrated into the manufacturing processes, including documentation. Depending on the product,

test intervals can be based on the following parameters:

Batch

Packing unit

Shipping unit

Working shift

Quantity in units

However, the test must be performed at least once a week.

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2.6.3 Test Methods and Testing Equipment

To perform the test required by para 2.6.2 of this organizational instruction, a suitable item of

testing equipment must be used. This equipment shall be regarded as suitable if the results

confirm the following:

A low error of measurement

Repeatability

Low dependence on personnel and environment factors

Thomas magnets GmbH has compiled a compact, powerful and low-cost system and recommends

this system for cleanliness analyses.

It is a particle counting system based on a scanner.

The device is compact, mobile and easy to operate. It allows automatic counting of particles and

an associated high level of results repeatability.

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Measurement takes place in an area that has been partitioned off.

2.7 Test Methods

2.7.1 Transport/Packaging

The packaging documented on the drawing shall be used. The internal packaging should be such

that the individual parts from Goods Receiving or from Production are protected against damage

and soiling. It is advisable to use clean polyethylene bags that permit prior labelling with “Product,

ID and Batch Number”. The bags shall be disposed of after the sampling procedure.

Cleanliness analysis:

Product-specific test parameters shall be documented in the PCP.

The analysis results of in-process inspections shall be recorded in an electronic/digital form (e.g.

MS Excel).

2.7.2 Control Sample

Determination of the blank sample (blank value) to calculate the gravimetric and determining the

cleanliness of items.

Equipment: Filter membrane Ultrasonic bath

Tweezers Mesh screen

Clamp Rinsing device

Suction flask Filter cascade

Funnel Filter plate

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2.7.2.1 Procedure

Particle extraction for individual parts:

Specify extraction method:

By client or depending on function and shape of the individual part.

Specify number of samples:

By client or determination using the decay method:

Note, the first sample of the decay curve should be a multiple of the control sample

Specify quantity of liquid:

By client or determination using the decay method.

Note, the last sample of the decay curve should be approximately the same size as the control

sample

Specify cleaning time:

By client or determination using the decay method.

Note, the last sample of the decay curve should be approximately the same size as the control

sample.

Control sample of the analysis equipment

Dry and weigh the filter beforehand

Take control sample with an appropriate quantity for blank value correction

Filter off over suction flask, rinsing device or cabinet

Rinse with 50ml petroleum benzene over suction flask

Dry filter for 1 hour at approx.. 80° C – 100° C and backweigh

Maximum gravimetric weight 0,5 mg -> if exceeded, change liquid

Individual parts

Dry and weigh the filter beforehand

Extract particles of individual parts with defined quantity of cold detergent

Filter off over suction flask, rinsing device or cabinet

Rinse with 50ml petroleum benzene over suction flask

Filter dried for 1 hour at approx.. 80° C – 100° C

Determination of gravimetric weight:

(Filter after filtering off in mg – filter before filtering off in mg) – blank value for analysis equipment

in mg = gravimetric weight in mg

Analysis of the filter membrane:

According to specification by client or according to VDA19

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2.7.3 Analysis of the Sample

2.7.3.1 Drying

Dry the filter in the drying oven at approx.. 100° C for a least 1 hour.

2.7.3.2 Rinse Down

Rinse down the individual parts with the appropriate volume of HAKU 1025-921 and fine-jet wash

bottle in a glass beaker.

Picture of an Example

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2.7.3.3 Filtration

Filter off the cleaning medium over suction flask. Assuming empty filter is dry.

Dry filter in the drying oven for at least 1 hour.

Place filter in slide frame,

Label the slide frame and analyze with an automatic particle counting system.

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2.7.3.4 Analysis with an Automatic Particle Counting System

Examples of inorganic particles:

Sand / metal / salts / glass / iron / grinding residues / brass

Grinding residues Sand

Lathe turnings

Example of organic particles:

Hairs / fibres / dust

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Filtration:

Consists of glass funnel that is mounted on a flask and connected to a vacuum pump.

Drying cabinet:

Dries the wet filter.

Automatic particle counting system:

With this system the accumulation of dirt particles on the filter patch is measured quantitatively.

Aids:

Filter patches (5 µm): for collecting dirt particles.

Beaker:

Container for collecting particles washed out and off in the rinsing medium.

Tweezers:

These are required in order to remove the filter patches from the filtration apparatus.

Cleaning medium:

Haku 1025-921

2.8 What Happens to the Individual Parts / Complete Devices Afterwards

The rinsed samples are generally scrapped in order to prevent contamination by introducing them to

production.

3. Associated Documents

ISO 16232

VDA 19.1

VDA 19.2

4. Advice

The German version is binding!