Pneumatic Wedge Grips

Instron pneumatic wedge action grips may be used in static or dynamic materials testing applications, interchangeable wedge-shape grip faces accommodating either flat or round specimens. 

The grip is designed to allow test specimens to be securely gripped without introducing axial pre-loading to the specimen. This is achieved by using jaw faces that move in a horizontal direction only, relative to the specimen.

Principle Of Operation

Each grip functions independently of the other, an external hydraulic supply providing pressure to both open and close the grips.

When gripping pressure is applied, the relative vertical position of the specimen/jaw faces remains unchanged to prevent specimen load generation during the gripping process. 

Once the grip faces contact the specimen the hydraulic pressure produces a vertical force on the grip head. The grip force will remain constant as the design automatically compensates for specimen thickness changes.

Application Range

  • Type of loading: Static or dynamic, reverse stress.
  • Specimen material: Metallics, plastics, composites.
  • Specimen geometries: Round section (not buttonhead) or flat specimens with or without shoulder tab.