Specimen Preparation for Metals

Good testing starts with a good specimen.

Nowadays test pieces from steel sheet and metal foils are produced economically and accurately using specimen blanking machines. Standards stipulate that test results must not be influenced by any material change caused by work hardening in the specimen edge zone.

Numerous structural examinations of steel sheet have shown that the work-hardened zone along the cutting line is generally a maximum of 10% of specimen thickness. This is achieved by a low cutting-speed and special blanking tool design and offers substantial economic advantages in the event of subsequent grinding. In this way high specimen quality is ensured.

Specimen Blanking

Advantages and features

  • Fast and cost-effective production of tensile specimens
  • No technical personnel required; machine can be operated by anyone after brief instruction
  • Finishing with grinder produces very high quality specimens
  • Robust, easy-to-maintain machines
  • Blanking tools have a long service life and are capable of repeated re-grinding.

Range of application

Nowadays test pieces from steel sheet and metal foils are produced economically and accurately using specimen blanking machines. Standards such as ISO 6892 and ASTMA 370 stipulate that test results must not be influenced by any material change caused by work hardening in the specimen edge zone.

Numerous structural examinations of steel sheet have shown that the work-hardened zone along the cutting line is generally a maximum of 10% of specimen thickness. This is achieved by a low cutting speed and special blanking tool design and offers substantial economic advantages in the event of subsequent grinding. In this way high specimen quality is ensured.

Blanking Tools

Blanking tools can be produced exactly in line with customers' requirements. For example, tools were produced from a special steel and provided with additional guides to enable dumbbell specimens to be punched from foils with a thickness of 0.04 mm and a tensile strength of 2,150 MPa. Depending on the strength of the material, between 20,000 and 150, 000 specimens can be produced using the tools. They can then be re-ground.

C-shaped specimen blanking machine (M-Cut 65)

The open design of the machine and the blanking tool (C-shape) allows removal of test pieces from sheets and foils also. If several blanking tools are in use, the side extension table (option) is recommended. This is in the form of a roller table and enables the blanking tools not currently required to be stored out of the way. Using the extension table, tool changes take about 20 seconds, offering significant time-savings in the event of frequent tool changes. The M-cut 65 specimen blanking machine (for 650kN compressive force) is suitable for material thicknesses from 0.04 to 6mm (depending on tensile strength and specimen shape).

O-shaped specimen blanking machines (RZ 100/RZ 150)

The closed O-shape requires precut strips. These blanking machines are already equipped with a side extension table.

Technical overview of specimen blanking

Technical data, M-Cut 65

Type

M-Cut 65

Item no.

048979

Pressure, max.

650

kN

Design

C-shaped

Punching from

Soft elastic foam

Piston stroke

20

mm

Strokes per minute

5

Specimen length, max.

300

mm

Electrical connected load

4

kVA

Dimensions:

Width

760

mm

Depth

760

mm

Height

1615

mm

Weight, approx.

1500

kg

Paint finish

RAL 7032

Technical data, RZ 100/RZ 150

Type

RZ 100

RZ 150

Item no.

890735

890710

Compressive force, max.

1000

1500

kN

Design

O-shape

O-shape

Punching from

Strip specimen

Strip specimen

Piston stroke

40

40

mm

Strokes per minute

6

6

Strip length, max.[1]

270

270

mm

Strip width, max.[1]

130

130

mm

Specimen length, max.

250

250

mm

Specimen width, max.

30

30

mm

Diameter of round specimens, max.

140

140

mm

Electrical connected load

8

8

kVA

Dimensions (without hydraulic power-pack):

Width

1600

1600

mm

Depth

750

750

mm

Height

1810

1810

mm

Approx. weight

2200

2200

kg

Paint finish

RAL 7021

Hydraulic power-pack (including)

Approx. weight

200

200

kg

Paint finish

RAL 7032

RAL 7032

Operating pressure

210

300

bar

Flow rate

7.4

7.4

l/min

Dimensions:

Width

900

900

mm

Depth

1010

1010

mm

Height

620

620

mm

Power specifications

400/50, 3 PH/PE

400/50, 3 PH/PE

V/Hz

Noise emission

<70

<70

db

  1. Punching from strip specimen
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