Wedge Screw Grips

Wedge-screw grips combine the mechanical properties of screw grips and wedge grips. Thickness is adjusted and a preload force is generated via a screw action, Specimen slipping at the beginning of the test is prevented. 

Key Advantages and Features

  • The main gripping force is generated by the wedge action.
  • The gripping force is proportional to the actual tensile force (self-clamping), ensuring secure gripping of a wide range of materials.
  • Large grip-to-grip separation allows the surface pressure to be kept low, avoiding jaw breaks.
  • The larger grips (from Fmax 50kN) can remain in place while small load cells, specimen grips, test fixtures and test devices are attached to them via the optional mounting unit – a great time-saver.
  • Wedge screw grips with Fmax 50 kN and above can be operated via a pneumatic motor, These specimen grips are opened and closed by a
  • pneumatic motor; the pneumatic actuator is located directly on the specimen grip
  • Low overall height.
  • Strain rate control to DIN EN ISO 6892-1:2009 and ASTM E8 – 09.

Switchable synchronization function

Switchable synchronization allows wedge-screw grips (Fmax 10 kN and over) to grip both symmetrically and asymmetrically. The asymmetry level is easily adjustable and is maintained reliably, even with re-gripping. This enables one-handed operation with either hand, including with asymmetrical specimens, and ensures that the specimen attachment point is always in the test axis.

Wedge Screw Grips 

Fmax 500 N
  • Probenmaterial:
    Vor allem Drähte, Eisen- und Nichteisenmetalle, aber auch Kunststoffe und Garne
  • Probenform:
    Rund- und Flachproben (Streifen und Schulterproben), Fäden
  • Beanspruchungsart:
    Zug

Advantages and features

  • The jaws are independently adjustable, enabling symmetrical and asymmetrical (glued specimen or shear test tensile specimen) specimen testing.
  • Needle bearing jaw guides in connection with flat wedge angles generate a gripping force of approximately 3.5 tensile force. In contrast to sliding guides, needle bearing jaw guides reduce friction losses and an unwanted stick slip effect.
  • The specimen grips are equipped with a centering device for threads and thread-like specimens.
  • Jaw markings for manual specimen centering.
  • Long clamping lengths hold clamping-sensitive and notch-sensitive specimens securely.

Technical data, Fmax 500 N

Item no.

313284

Type

8106

Test load, max. (Fmax)

0.5

kN

Height

63

mm

Width

94

mm

Depth

28

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width, max. for symmetrical gripping

5

mm

Weight per specimen grip (without jaws), approx.

200

kg

Connection

Ø 8

mm

Ambient temperature

-40 to +250[1]

°C

Scope of delivery

2

pieces

  1. It is possible that the temperature range is limited by a smaller jaw temperature range.

Wedge Screw Grips 

Fmax 2.5 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • The jaws are independently adjustable, enabling symmetrical and asymmetrical (glued specimen or shear test tensile specimen) specimen testing.
  • Needle bearing jaw guides in connection with flat wedge angles generate a gripping force of approximately 3.5 tensile force. In contrast to sliding guides, needle bearing jaw guides reduce friction losses and an unwanted stick slip effect.
  • The specimen grip is equipped with a centering device for threads and thread-like specimens.
  • No synchronization of the jaws.

Technical data, Fmax 2.5 kN

Item no.

313398

Type

8206

Operating principle/identification

Simple version

Test load, max. (Fmax)

2.5

kN

Height

115

mm

Width

152

mm

Depth

57

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width, max. for symmetrical gripping

10

mm

Weight per specimen grip (without jaws), approx.

3

kg

Connection

Ø 20

mm

Ambient temperature

-40 ... +250[1]

°C

Scope of delivery

2

pieces

  1. It is possible that the temperature range is limited by a smaller jaw temperature range.

Wedge Screw Grips 

Fmax 10 kN
  • Probenmaterial:
    hochfeste Drähte und Bänder aus Eisen- und Nichteisenmetalle, Verbundwerkstoffe, harte und verstärkte Kunststoffe
  • Probenform:
    Rund- und Flachproben (Streifen und Schulterproben)
  • Beanspruchungsart:
    Zug

 Ideal for use in temperature chambers.

Advantages and features

  • The jaws are independently adjustable, enabling symmetrical and asymmetrical (glued specimen or shear test tensile specimen) testing.
  • The gripping force/tensile force ratio offers very high gripping forces, twice as high as with other wedge screw grips.
  • Needle bearing jaw guides with sliding plates reduce an unwanted stick slip effect. Due to the low friction, the tensile force is transmitted directly as the gripping force to the specimen without transfer loss.
  • The specimen grips are equipped with a centering device for threads and thread-like specimens as well as an adjustable centering stop with scale for the accurate positioning of specimen up to 50 mm wide.
  • The design provides good accessibility to the specimen grip and offers ample space for flexible specimen ends.
  • The specimen grip is easy to use thanks to a convenient hand wheel for opening and closing the jaws.
  • High temperature resistance (-70 to +150 °C) makes wedge screw grips ideal for use in temperature chambers.

Technical data, Fmax 10 kN

Type

8305

Item no.

021140

Test load Fmax

10

kN

Height

143

mm

Width at max. opening of jaws (Handwheels untwisted)

246

mm

Depth

108

mm

Gripping of the specimen

The specimen must be gripped above at least 2/3 of the jaw height.

Opening width, max. for symmetrical insertion

20

mm

Connection

Ø 20

mm

Ambient temperature

-70 to +150[1]

°C

Weight per specimen grip (without jaws), approx.

8.6

kg

Scope of delivery

2

pieces

  1. It is possible that the temperature range is limited by a smaller jaw temperature range.
04_wedge screw_10kN_plastics-black_makroXtens_FO

Wedge Screw Grips 

Fmax 10 kN and 30 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • Switchable synchronization allows wedge screw grips to grip both symmetrically and asymmetrically (for example testing shear specimens).
  • The asymmetry level is easily adjustable and is maintained reliably, even with regripping. This enables one-handed operation with either hand, including with asymmetrical specimens, and ensures that the specimen attachment point is always in the test axis.
  • Jaws can be changed easily without tools.
  • Low overall height.
  • Flat jaws are equipped with a centering stop.

Technical data, Fmax 10 kN and 30 kN

Item no.

317404[1]

317394[1]

Test load, max. (Fmax)

10

30

kN

Type

8306

8406

Height

125

137

mm

Width

319

319

mm

Depth

93

93

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width/specimen thickness, max. for symmetrical gripping

See table of jaws

See table of jaws

Weight per specimen grip (without jaws), approx.

15

16

kg

Gripping travel

7

7

mm

Connecting diameter

20

36

mm

Ambient temperature

-40 to +250[2]

-40 to +250[2]

°C

Scope of delivery

2

2

pieces

  1. Recommended and approved for strain rate control in accordance with standards DIN EN ISO 6892-1:2009 and ASTM E8 – 09
  1. It is possible that the temperature range is limited by a smaller jaw temperature range.

Wedge Screw Grips 

Fmax 50 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • Synchronized opening and closing the jaws.
  • Synchronization can be switched off; symmetrical and asymmetrical gripping is possible, enabling gripping of asymmetrical specimen (for example glued shear specimen).
  • Jaws can be changed easily without tools.
  • Low overall height.
  • Flat jaws are equipped with a centering stop.
  • Small load cells, specimen grips, tools and fixtures can be quickly accommodated via the optional mounting unit and without having to dismantle the specimen grips.

Technical data, Fmax 50 kN

Item no.

317160[1]

318659[1]

Type

8406

8406

Operating principle/identification

Mechanical opening/closing

Motorized opening/closing

Test load, max. (Fmax)

50

50

kN

Height

146

147

mm

Width

385

408

mm

Depth

115

173

mm

Depth with stop strip/actuation unit

135

191

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width/specimen thickness, max. for symmetrical gripping

See table of jaws

Gripping travel

8

8

mm

Operating pressure, max. of pneumatic motor

-

7

bar

Air consumption

-

5

l/s

Closing/opening speed at 6 bar

-

5

mm/s

Motor noise level

-

72

dB (A)

Weight per specimen grip (without jaws), approx.

37

50

kg

Connecting diameter

36

36

mm

Ambient temperature

-40 to +250[2]

+10 to +35

°C

Scope of delivery

2

2

pieces

  1. Recommended and approved for strain rate control in accordance with standards DIN EN ISO 6892-1:2009 and ASTM E8 – 09
  1. It is possible that the temperature range is limited by a smaller jaw temperature range.

Wedge Screw Grips 

Fmax 100 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • Synchronized opening and closing the jaws.
  • Synchronization can be switched off; symmetrical and asymmetrical gripping is possible, enabling gripping of asymmetrical specimen (for example glued shear specimen).
  • Jaws can be changed easily without tools.
  • Low overall height.
  • Flat jaws are equipped with a centering stop.
  • Small load cells, specimen grips, tools and fixtures can be quickly accommodated via the optional mounting unit and without having to dismantle the specimen grips.

Technical data, Fmax 100 kN

Item no.

316901[1]

318661[1]

Type

8506

8506

Operating principle/identification

Mechanical opening/closing

Motorized opening/closing

Test load, max. (Fmax)

100

100

kN

Height

176

177

mm

Width

371

408

mm

Depth

115

173

mm

Depth with stop strip/actuation unit

135

188

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width/specimen thickness, max. for symmetrical gripping

See table of jaws

See table of jaws

Gripping travel

8

8

mm

Operating pressure, max. of pneumatic motor

-

7

bar

Air consumption

-

5

l/s

Closing/opening speed at 6 bar

-

5

mm/s

Motor noise level

-

72

dB (A)

Weight per specimen grip (without jaws), approx.

44

50

kg

Connecting diameter

60

60

mm

Ambient temperature

-40 to +250[2]

+10 to +35

°C

Scope of delivery

2

2

pieces

  1. Recommended and approved for strain rate control in accordance with standards DIN EN ISO 6892-1:2009 and ASTM E8 – 09
  1. It is possible that the temperature range is limited by a smaller jaw temperature range.

Wedge Screw Grips 

Fmax 150 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • Synchronized opening and closing the jaws.
  • Synchronization can be switched off; symmetrical and asymmetrical gripping is possible, enabling gripping of asymmetrical specimen (for example glued shear specimen).
  • Jaws can be changed easily without tools.
  • Low overall height.
  • Flat jaws are equipped with a centering stop.
  • Small load cells, specimen grips, tools and fixtures can be quickly accommodated via the optional mounting unit and without having to dismantle the specimen grips.

Technical data, Fmax 150 kN

Item no.

318250[1]

050156[1]

Type

8506

8506

Operating principle/identification

Mechanical opening/closing

Motorized opening/closing

Test load, max. (Fmax)

150

150

kN

Height

176

176

mm

Width

416

422

mm

Depth

140

192

mm

Depth with stop strip/actuation unit

159

292

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width/specimen thickness, max. for symmetrical gripping

See table of jaws

See table of jaws

Gripping travel

8

8

mm

Operating pressure, max. of pneumatic motor

-

7

bar

Air consumption

-

5

l/s

Closing/opening speed at 6 bar

-

5

mm/s

Motor noise level

-

72

dB (A)

Weight per specimen grip (without jaws), approx.

49

59

kg

Connecting diameter

60

60

mm

Ambient temperature

-40 to +250[2]

+10 to +35

°C

Scope of delivery

2

2

pieces

  1. Recommended and approved for strain rate control in accordance with standards DIN EN ISO 6892-1:2009 and ASTM E8 – 09
  1. It is possible that the temperature range is limited by a smaller jaw temperature range.
04_wedge screw_250kN_manual_cracked metal2_FO

Wedge Screw Grips 

Fmax 250 kN
  • Specimen material:
    Ferrous and non-ferrous metals, hard and toughened plastics, fiber composites, wood, similar materials
  • Specimen shape:
    Round specimens, flat specimens, with or without reinforced ends (strip specimens or dumbbells)
  • Type of loading:
    Tensile

Advantages and features

  • Synchronized opening and closing the jaws.
  • Synchronization can be switched off; symmetrical and asymmetrical gripping is possible, enabling gripping of asymmetrical specimen (for example glued shear specimen).
  • Jaws can be changed easily without tools.
  • Flat jaws are equipped with centering stop.
  • Small load cells, specimen grips, tools and fixtures can be quickly accommodated via the optional mounting unit and without having to dismantle the specimen grips.

Technical data, Fmax 250 kN

Item no.

318596[1]

318598[1]

Type

8507

8507

Test load, max. (Fmax)

250

250

kN

Open/close

Manual

Gripping force at Fmax

482.5

kN

Height

252

252

mm

Width

522

541

mm

Depth

158

210

mm

Depth with actuation unit

-

225

mm

Gripping of the specimen

The specimen must be gripped above at least 1/2 of the jaw height.

The specimen must be gripped above at least 1/2 of the jaw height.

Opening width/specimen thickness, max. for symmetrical gripping

See table of jaws

See table of jaws

Operating pressure, max. of pneumatic motor

-

7

bar

Closing/opening speed at 6 bar

-

5

mm/s

Motor noise level

-

64

dB (A)

Weight per specimen grip (without jaws), approx.

108

112

kg

Weight per jaw, approx.

2.3

2.3

kg

Connecting diameter

60

60

mm

Ambient temperature

-40 to +250[2]

+10 to +35

°C

Scope of delivery

2

2

pieces

  1. Recommended and approved for strain rate control in accordance with standards DIN EN ISO 6892-1:2009 and ASTM E8 – 09
  1. It is possible that the temperature range is limited by a smaller jaw temperature range.
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