Hardened and tempered steel strip

02 Hardened and tempered steel strip

Down! Come! Fetch! And Down again! What has our hardened and tempered steel strip got to do with dog commands?If you have a dog that is very active you might appreciate a retractable dog leash, which

gives your dog the greatest possible freedom of movement without it feeling restricted

from a leash. Hardened and tempered steel strip produced by C.D. Wälzholz ensures

a smooth and long lasting mechanism. Many of our customers’ products using materials

made by CDW cannot be detected at first glance – just like this retractable dog leash.

But one thing is certain: you will realise our quality immediately.

Our hardened and tempered steel strip has proved itself in daily practice for many years.

Innovations as well as continuous enhancements of this material are of crucial

importance to us. Our efforts have been successful: today hardened and tempered steel

strip is one of our key products. We are also an international market leader in this sector.

On the following pages we will introduce you to the variety of hardened and tempered

steel strip grades, and we will also show you how to find the best solution to meet your

particular product requirements.

03Hardened and tempered steel strip

You can rely on it at all times: Hardened and tempered steel stripWe attach great importance to an application-oriented approach and are constantly

enhancing and improving our steel strip, thus extending the application range with

a variety of different microstructures. The material is available as martensitic hardened

and tempered steel strip, as SORBITEX® texture-rolled steel strip or as PT strip.

In co-operation with your company we will develop the optimal solution for all your

individual requirements. We support the development process on the basis of our highly

specialised quality management system and are therefore able to guarantee the highest

product quality and the best results – continuously!

Your products are versatile – and so is the hardened and tempered steel strip made by CDW.

It is used in vacuum cleaners, lawnmowers and secateurs; it ensures lasting saw blade

sharpness and, in the shape of a spring in the retracting mechanism, will always pull the

seat belt back to the correct position.

Excellent innovations

04

One type of material within our range of hardened and tempered steel strip is

martensitic hardened steel. It fulfils the narrowest tolerances and is extremely flat.

Therefore it is particularly suitable for products demanding precision, homogeneity

as well as hardness, and which at the same time has to withstand high stresses and

strains. Martensite is used e. g. in pneumatic shock absorber plates or in compressor

flapper valves. These devices are exposed to strong cyclic stresses and strains.

Martensite can also be relied upon when manufacturing high-performance saw blades.

Our material guarantees an extraordinary precision for all end products. No matter if

laser cut or machined.

A prime example for what we are able to do with the innovative martensite is the award-

winning “Aerotwin” windscreen wiper with custom-designed flex rails and balanced force

distribution for better sight, improved winter performance and longevity.

Hardened and tempered steel strip

for further details: www.cdw.de

Thickness 0.08 - 4.0 mm

Width 7 - 650 mm

Tolerances according to EN 10140 and special agreements

Delivery form pancake coils, oscillated wound coils and fixed lengths

Material according to EN 10132 3 + 4 and special grades, PT, SORBITEX®

Surface greyblue, bright, polished, ground, brushed

The main feature of our hardened and tempered

steel strip is its versatility, which is particularly

due to the variety of different microstructures

ensuring a wide application range for this

material. One product in this group is PT strip,

one of our specific developments and the best

choice for accurate solutions. The unique material

properties of PT strip allow specific forming

despite high tensile strength. Thus intricate piece

hardening is not necessary – certainly an

advantage for you. Extremely precise springs

and flat springs as well as complex metal working

parts can be manufactured using this specific

material. They are predominantly suitable for

static loads e. g. in connection with various

pressure plates or fasteners elements and

meet the closest form tolerance requirements.

05

Outstanding spring suspension

Hardened and tempered steel strip

High carbon steel / spring steel Martensitic hardening and tempering according to EN 10132-4

Bainite hardeningPT strip

Grades Tensile strength Grades Tensile strength

[N/mm2] [N/mm2]

34Mn5 PT 90 Mn 800 - 1,000

C45E PT 100 900 - 1,100

C55S 1,100 - 1,700 PT 110 1,000 - 1,200

C60S 1,150 - 1,750 PT 120 1,100 - 1,300

C67S 1,200 - 1,900 PT 130 1,200 - 1,400

C75S 1,200 - 1,900 PT 140 1,300 - 1,500

C80S 1,200 - 1,900 PT 150 1,400 - 1,600

C85S 1,200 - 2,000

C90S 1,200 - 2,100

C100S 1,200 - 2,100

56Si7 1,200 - 1,700

51CrV4 1,200 - 1,800

06

SORBITEX® texture-rolled steel strips are the

basic material for the production of particularly

robust and reliable springs. They work efficiently

in retraction devices found in dog leashes,

vacuum cleaners and lawnmowers. The secret of

the SORBITEX® steel strip is its texture providing

extreme spring properties, maintained even at

permanent loads.

In order to optimise these properties the

material is undergoing a complex production

process at CDW. We perform a special heat

treatment procedure and strongly cold work of

the microstructure. This is how we achieve the

desired texture.

Due to its specific properties SORBITEX® texture-

rolled steel strip is interesting for a number

of industrial sectors. Primarily the automotive

industry really appreciates the advantages of

this material and uses it in numerous products.

For applications in this industry CDW works in

product development specification oriented.

The retractor springs in seat belts made of our

texture-rolled steel strip, for example, are fail-

safe, enormously endurable and have a tensile

strength of up to 3,000 N/mm2.

Highest force in the smallest space

Hardened and tempered steel strip

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4

3,200

3,000

2,800

2,600

2,400

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

Tens

ile s

tren

gth

[N/m

m2 ]

Range of specific values

Strip thickness [mm]

07Hardened and tempered steel strip

Bainite / PT

Sorbite / PS

Martensite / QT

08

All’s well that ends well

For the production of hardened and tempered

steel strip CDW uses 4-stand tandem rolling mills

and 20-roll mills, which are able to achieve speeds

of up to 850 metres a minute. Furthermore, we

use the latest computer technology to attain the

required precision; by means of non-contact x-ray

and isotope measuring strip thicknesses are

recorded so that roll positions can be automatically

adjusted. Moreover, strip length and speed data is

collected by means of laser beams.

The subsequent hardening and tempering finally

completes the product. In order to optimise the

microstructure we use appropriate, well adapted

process engineering. Thus we distinguish

between sorbitic, bainite and martensitic

processes in this multi-stage process of cold

rolling, heat treatment and second cold rolling.

These procedures differ as to the temperature

of the metal bath and will consequently influence

the development of the required microstructure

properties in each case.

For the production of SORBITEX® texture-rolled

steel strip and PT strip two heat treatment lines

with state-of-the-art process management are

employed. We also have five wide strip lines

and three narrow strip lines for hardening and

tempering of martensitic steel grades.

Hardened and tempered steel strip produced by C.D. Wälzholz is a power-pack! It is

wear-resistant and break-proof, of high-grade precision and works reliably even under

strong strains and stresses.

Our highly specialised production procedure covering every step from raw material to

end product ensures that the steel will obtain its valuable properties. Additionally, we

constantly support the entire production process on the basis of our quality and process

management system. Consequently we are able to guarantee a continuously high quality

for all our products.

Hardened and tempered steel strip

Round and wound – our oscillated wound coilsAll processes at CDW are subject to a demanding quality and process management

optimising the production of our hardened and tempered steel strip right from the start

and we will not be happy before all our customers are happy! One good example for our

efforts is the continuous enhancement of our oscillated wound coils.

These coils help our customers to stay ahead of competitors in a number of ways. The

increased length of the individual steel strips from 1,000 to 30,000 metres provides for

more economic production and steel strips can be joined by means of modern welding

technology and computer-controlled oscillating winding procedure.

Thanks to 30 times longer operating times labour-intensive set-up times and

unprofitable shutdown times are minimised.

Here they are again in short form – the advantages of our oscillated wound hardened and tempered steel strip coils: » Strip widths of up to 70 mm

» Operating times / strip lengths up to 30 times longer

» Individual coil widths of 250 - 550 mm

» Jumbo coils with a weight of up to 3,500 kg

09Hardened and tempered steel strip

10

The best travel insurance – our packagingTo ensure quality for our customers we have the

highest demands in material and production.

For us at C.D. Wälzholz it is important that our

hardened and tempered steel strip coils reach

your company in perfect condition. Therefore we

aim for the highest quality and exacting standards

not only in regards to production and material, but

also with respect to packaging and shipment. Our

modern automatic packaging equipment can

guarantee smooth logistics between production

line and shipping department and protect each

product according to our customers’ requirements.

Hardened and tempered steel strip can be supplied

in a number of forms, namely in fixed lengths,

pancake coils with an outside diameter of up to

1,850 mm and oscillated wound coils with a weight

of up to 3.5 tons.

The different the transport options to national or

international destinations are, the numerous our

packaging options are. Take our heavy-duty

overseas packaging, for example. It will most

definitely withstand the strains of long and rough

transportation across the ocean.

Behind every packaging idea there is one thought:

Sometimes less is more! We will never use more

material than is absolutely necessary. After all,

this is for the benefit of the environment and of

our customers. Owing to our long international

experience we have continuously improved our

packaging: optimal protection, clear marking and

distinct traceability are the results of such an

extensive experience.

Hardened and tempered steel strip

11

C.D. Wälzholz – at home everywhere in the worldSteel is an extremely versatile material. The C.D. Wälzholz Group of Companies is just as

versatile itself. As a progressive German cold rolling mill with a long tradition,

C.D. Wälzholz today has subsidiaries and agencies all over the world. Therefore we are in

a position to offer our international customers hardened and tempered steel strip in

virtually any type and grade required – everywhere in the world.

Satisfied customers, highest quality as well as a responsible handling of the environment

are our goal. Always.

Hardened and tempered steel strip

Cold rolled high carbon steel strip

Hardened and tempered steel strip

Electrical steel strip

Cold rolled low carbon steel strip

Bonderized steel strip

Narrow steel strip

Profiles

C.D. Wälzholz KGFeldmühlenstr. 55 58093 HagenGermany

Phone: +49 (0) 23 31- 9 64 - 0Fax: +49 (0) 23 31- 9 64 - 21 00Internet: www.cdw.deE-mail: info@cdw.de

Locations: Hagen, Hohenlimburg, Plettenberg, Oberkochen, Iserlohn/Germany Götzis/Austria . Thiers/France São Paulo/Brazil . Cleveland, Ohio/USA . Taicang/China

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