MTS Series 647 Hydraulic Wedge Grips - Manual (Page 89)

6.
Caution:
The contact area between the wedge face and specimen should be as large as possible.
A small contact area between the wedge face and specimen can cause premature wear to
the wedge face surface.
MTS recommends that specimens should be machined to provide the largest possible surface
contact area between the wedge face and the specimen.
Caution:
Wedges can be installed incorrectly.
Improper specimen installation can damage the wedges.
Install the specimen in the wedges precisely as specified in the following steps.
Place the specimen in the lower grip allowing a space of at least 3 mm (0.12 in) but not greater than 6
mm (0.25 in) between the bottom of the specimen and the bottom inner edges of the lower grip wedges.
Lock the lower grip.
Description Item
Wedge Face 1
Contact Area (HxW) 2
Bottom Gap Specification (3-6 mm) 3
Large contact area recommended. 4
Small contact area can cause premature wear. 5
Series 647 Hydraulic Wedge Grips Reference Manual 89
Operation