Wedge grips

Material

Metals
Plastics
Wood

Test load

2.5 kN - 250 kN

Specimen shape

Round specimens
Flat specimens

Type of test

Tensile

Ideal for quality assurance

The wedge grip is a symmetrically closing specimen grip. A lever is used to open and close the grips, as well as apply gripping force before the test.

A distinction is made between two operating principles:

Body over wedge (also BoW)
Lever

Advantages & features

Body over wedge operating principle

Wedge grips operating on this principle apply a greater preloading force when the specimen is inserted. The preload applied to the specimen is transmitted to the jaws via the body of the grips using a lead screw. In this case also the main gripping force is not attained until during tensile loading (via the wedge effect). Grips of this type have two additional advantages: Specimens inclined to slippage are gripped more firmly right from the beginning and the gripping length remains constant, even if thickness varies from specimen to specimen. In addition, strain-rate control to ISO 6892-1 (2009) Method A (closed loop) and ASTM E 8 (2009) Method B can be applied with greater precision.

Advantages of body over wedge principle

The modular design of the grips allows them to be configured for manual or pneumatic actuation according to requirements.
With specimen grips from the body over wedge portfolio, the position of the jaws remains constant in the test direction as the specimen is gripped. This means that the grip-to-grip separation does not depend on the specimen thickness.
The manual version offers a cost-efficient, simple, and robust solution. Actuation via the radially mounted lever enables high preload forces.
With the pneumatic version the emphasis is on fast, reproducible and, most importantly, parallel gripping. Full gripping force is available right from the start, so that the static jaws transfer the test speed directly to the specimen. When working with a temperature chamber, simple extensions are used. The pneumatic actuator is positioned outside the chamber.

Lever operating principle

Wedge grips operating on this principle are self gripping. During insertion a preload is applied to the specimen via operation of the lever and a spring. However, it is only during tensile loading that the main gripping force is attained via the wedge effect. The gripping pressure maintains a constant relationship to the tensile force through displacement of the wedges. The advantage of grips of this type is that the test can be performed very quickly and does not require the operator to exert too much force.

Advantages of lever principle

The closing force is proportional to the tensile force (self-gripping).
Wedge grips always close symmetrically with respect to the tensile axis.
Long clamping length and good jaw guiding properties allow contact pressure on the specimen to be kept to a minimum.
High temperature resistance and low overall height makes specimen grips ideal for use in temperature chambers.
The wedge grip design ensures fast and energy-saving operation using a lever.
The lever can be locked when the wedge grips are open.

Wedge grips, Fmax 150 kN

Body over wedge specimen grips, Fmax 100 kN

Wedge grips, Fmax 10 kN, wire testing

Wedge grips, Fmax 10 kN

Wedge grips, Fmax 50 kN

Wedge grips, Fmax 5 kN

Body over wedge specimen grips, Fmax 50 kN

Body over wedge specimen grips, Fmax 250 kN

Technical overview

Type	8304
Item No.	1004955¹²
Test load F_max	10	kN
Operating principle/identification	Wedge action
Dimensions
Height	195	mm
Width	130	mm
Width With actuation lever	207	mm
Depth	73	mm
Depth With actuation lever	207	mm
Opening width, max. with jaws	6.5	mm
Clamping length	min. 20	mm
Weight per specimen grip, approx.	5.2	kg
Connection, stud	Ø 20	mm
Ambient temperature	-70 ... +250	°C
Scope of delivery	2	pieces

A load cell with a limit torque of at least 200 Nm is required (e.g. Type Xforce K).
Recommended and approved for strain rate control to the standards DIN EN ISO 6892-1:2009 and ASTM E8-09

Type	8404
Item No.	1006757¹²
Test load F_max	50	kN
Dimensions
Height (without centering stop)	224	mm
Width	170	mm
Width with actuation lever	220	mm
Depth	97	mm
Depth with actuation lever	220	mm
Gripping area
Height	60	mm
Width	35/60	mm
Opening width, max. with jaws	22	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Weight per specimen grip, approx.	11	kg
Connection, stud	Ø 36	mm
Ambient temperature	-70 ... +250	°C
Scope of delivery	2	pieces

Recommended and approved for strain rate control to the standards DIN EN ISO 6892-1:2009 and ASTM E8-09
A load cell with a limit torque of at least 200 Nm is required (e.g. type K or type P).

Type	8504
Item No.	080384¹²
Test load F_max	100	kN
Operating principle/identification	Wedge action (symmetrically closing)
Dimensions
Height	260	mm
Width	200	mm
Width with actuation lever	236	mm
Depth	94	mm
Depth with actuation lever	236	mm
Opening width, max. with jaws	22	mm
Gripping of the specimen, min.	30	mm
Gripping area
Height	60	mm
Width	35/60	mm
Weight per specimen grip, approx.	18	kg
Connection, stud	Ø 60	mm
Ambient temperature	-70 ... +250	°C
Scope of delivery	2	pieces

Recommended and approved for strain rate control to standards DIN EN ISO 6892-1:2009 and ASTM E8-09
A load cell with a limit torque of min. 200 Nm is required (e.g. type K or type P).

Item No.	1003525¹
Type	8510
Operating principle/identification	Wedge action
Test load F_max	250	kN
Dimensions
Height	323	mm
Width	300	mm
Widthwith actuation lever	409	mm
Depth	140	mm
Depthwith actuation lever	409	mm
Opening width with jaws	35	mm
Gripping of the specimen	The specimen must be gripped over a distance of at least 60 mm.
Clamping surface
Height	60	mm
Width	60	mm
Connection, hole	Ø 60	mm
Weight per specimen grip, approx.	61	kg
Ambient temperature	-70 ... +250	°C
Scope of delivery	2	piece(s)

Recommended and approved for strain rate control to standards DIN EN ISO 6892-1:2009 and ASTM E8–09.

Type	8201	8201
Item No.	320454	353408
Test load F_max	2.5	2.5	kN
Dimensions
Height	145	145	mm
Width	120	120	mm
Depth	58	58	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	11	-	mm
Opening width, max. with jaws, thickness 5 mm	-	11¹	mm
Weight per specimen grip, approx.	2.4	1.9	kg
Connection, stud	Ø 20	Ø 20	mm
Ambient temperature	-40 ... +250	+40 ... +250	°C
Scope of delivery	1	2	pieces
Jaws supplied
Surface	Fsc² 0.75	-	mm
Gripping area
Height	40	-	mm
Width	32	-	mm
Hardness	61 HRC	-

This opening width results when using the jaw mountings mentioned below and jaws with 5-mm jaw strength.
Fsc = fish scale

Type	8201	8201
Item No.	320456	318975
Test load F_max	5	5	kN
Dimensions
Height	145	145	mm
Width	120	120	mm
Depth	58	58	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	11	-	mm
Opening width, max. with jaws, thickness 5 mm	-	11	mm
Weight per specimen grip, approx.	2.4	1.9	kg
Connection, stud	Ø 20	Ø 20	mm
Ambient temperature	-40 ... +250	-40 ... +250	°C
Scope of delivery	1	2	piece
Jaws supplied
Surface	Fsc¹ 0.75	-	mm
Gripping area
Hardness	61 HRC	-

Fsc = fish scale

Type	8302	8302
Item No.	320458	318884
Test load F_max	10	10	kN
Dimensions
Height	165	165	mm
Width	156	156	mm
Depth	83	83	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	12.5	-	mm
Opening width, max. with jaws, thickness 5 mm	-	0 ... 12.5/8 ... 20.5¹	mm
Weight per specimen grip, approx.	8	6.5	kg
Connection, stud	Ø 20	Ø 20	mm
Ambient temperature	-40 ... +250	-40 ... +250	°C
Scope of delivery	1	2	piece
Jaws supplied
Surface	Fsc² 0.75	-	mm
Gripping area
Height	50	-	mm
Width	60	-	mm
Hardness	61 HRC	-

Depending on the jaws used
Fsc = fish scale

Type	8302	8302
Item No.	320460	318886
Test load F_max	20	20	kN
Dimensions
Height	177	177	mm
Width	156	156	mm
Depth	83	83	mm
Gripping of the specimen	-
Opening width, max. with jaws	12.5	-	mm
Weight per specimen grip, approx.	8	6.5	kg
Connection, stud	Ø 36	Ø 36	mm
Ambient temperature	-40 ... +250	-40 ... +250	°C
Scope of delivery	1	2	piece
Jaws supplied
Surface	Fsc¹ 0.75	-	mm
Gripping area
Height	50	-	mm
Width	60	-	mm
Hardness	61 HRC	-

Fsc = fish scale

Type	8303
Item No.	313492
Test load F_max	10	kN
Dimensions
Height	110	mm
Height with closed jaws	114	mm
Width	81	mm
Width with actuation lever	111	mm
Depth	74	mm
Depth with actuation lever	186	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	4.5	mm
Connection, stud	Ø 20	mm
Ambient temperature	-40 ... +250	°C
Weight per specimen grip, approx.	3	kg
Scope of delivery	2	pieces

Type	8403
Item No.	313610
Test load F_max	50	kN
Dimensions
Height	196	mm
Height with closed jaws	206	mm
Width	144	mm
Width with actuation lever	215	mm
Depth	88	mm
Depth with actuation lever	215	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	10	mm
Gripping area
Height	77	mm
Width	30	mm
Connection, stud	Ø 36	mm
Ambient temperature	-40 ... +250	°C
Weight per specimen grip, approx.	10	kg
Scope of delivery	2	pieces

Type	8402	8402
Item No.	325312	353416
Test load F_max	30	50	kN
Dimensions
Height	165	165	mm
Width	160	160	mm
Width with actuation lever	180		mm
Depth	130	130	mm
Depth with actuation lever	252		mm
Width With actuation lever		180
Depth With actuation lever		252
Gripping area
Height	60	60	mm
Width	60	60	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	18	18	mm
Specimen dimensions
Flat specimen, thickness	... 18	... 18	mm
Round specimen, Ø	... 18	... 18	mm
Weight per specimen grip, approx.	13.5	13.5	kg
Connection, stud	Ø 36	Ø 36	mm
Ambient temperature	-40 ... +250	-40 ... +250	°C
Scope of delivery	2	2	pieces

Type	8502
Item No.	320129
Test load F_max	100	kN
Dimensions
Height	210	mm
Width	253	mm
Depth	175	mm
Depth with actuation lever	260	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Weight per specimen grip, approx.	27	kg
Connection, stud	Ø 60	mm
Ambient temperature	-40 ... +250	°C
Scope of delivery	2	pieces

Type	8509
Item No.	324550
Test load F_max	150	kN
Dimensions
Height	255	mm
Width with actuation lever	395	mm
Depth with actuation lever	291	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width, max. with jaws	32	mm
Weight per specimen grip, approx.	47	kg
Weight per jaw, approx.	2.0 ... 2.5	kg
Connection, stud	Ø 60	mm
Ambient temperature	-40 ... +250	°C
Scope of delivery	2	pieces

Item No.	600619	1106809
Type	8509	8509¹
Test load F_max	250	250	kN
Dimensions
Height	320	320	mm
Width	350	350	mm
Depth	120	120	mm
Gripping of the specimen	The specimen must be gripped with at least 2/3 of the jaw height.	The specimen must be gripped with at least 2/3 of the jaw height.
Opening width and specimen thickness	See table of jaws	See table of jaws
Weight per specimen grip, approx.	70	75	kg
Connection, stud	Ø 60	Ø 60	mm
Ambient temperature	-40 ... +100	+10 ... +35	°C
Scope of delivery	2	2	pieces

Includes pneumatic actuator. A pneumatic control unit is required.

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Downloads

Product brochure: Specimen Grips and Test Tools PDF 4 MB
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- EN
Product information: Wedge grips, Fmax 2,5 kN / 5 kN PDF 161 KB
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Product information: Wedge grips, Fmax 10 kN / 20 kN PDF 713 KB
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Product information: Wedge grips, Fmax 10 kN / 50 kN PDF 230 KB
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Product information: Wedge grips body over wedge, Fmax 10 kN PDF 690 KB
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Product information: Wedge grips, Fmax 30 kN / 50 kN PDF 295 KB
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Product information: Wedge grips body over wedge, Fmax 50 kN PDF 427 KB
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Product information: Wedge grips, Fmax 100 kN PDF 349 KB
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Product information: Wedge grips body over wedge, Fmax 100 kN PDF 451 KB
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- EN
Product information: Wedge grips, Fmax 150 kN PDF 259 KB
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- EN
Product Information: Wedge grips body over wedge, Fmax 250 kN PDF 444 KB
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Wedge Grips