The fixture system of the copper strip tensile strength testing machine is designed to prevent the copper strip specimen from slipping, avoid edge pinch injuries, and ensure axial load application. It needs to be adapted to the testing requirements of specimens with different thicknesses (from ultra-thin copper foil to thick copper strip). The common types and characteristics are as follows:

Flat mouth self-locking fixture

Structure: Composed of two sets of upper and lower jaws, with a flat jaw surface and a built-in inclined self-locking mechanism. When the testing machine applies a tensile load, the larger the load, the stronger the clamping force of the jaws on the specimen, achieving Self locking effect.

Adaptation scenario: Suitable for thicknessConventional copper strips ranging from 0.1mm to 5mm (such as brass strips and copper strips) are the mainstream fixtures for industrial quality inspection.

Key design: The jaw material is made of hard alloy or quenched steel, and the surface can be treated with fine lines to increase the friction with the copper strip; Jaw width adjustable (usually10~50mm）， Suitable for copper strip samples of different widths.

Pneumatic flat mouth fixture

Structure: Using compressed air as the power source, the sample is clamped by the jaws driven by a cylinder, and the clamping force can be accurately set through a pressure regulating valve.

Adaptation scenario: Suitable for batch sample testing (such as production line quality inspection), or scenarios that require high consistency of clamping force, to avoid testing errors caused by uneven manual clamping force.

Advantages: Automated clamping and releasing actions, high efficiency; Stable clamping force and good repeatability, especially suitable for copper strip samples with uniform thickness.

Soft pad flat mouth fixture

Structure: Install a layer of soft pad (such as polyurethane, rubber, soft metal sheet) on the inner side of the flat jaw, and the rest of the structure is consistent with the self-locking fixture.

Adaptation scenario: specifically designed for ultra-thin copper foil (thickness<0.1mm) or precision copper strip with easily scratched surface.

Advantages: The soft pad can cushion the clamping force, avoiding the edge of the copper foil from being cracked or the surface from being pressed, while ensuring sufficient friction to prevent slipping.

Wedge-shaped fixture

Structure: The jaw is designed with a wedge-shaped inclined surface. After the specimen is inserted into the wedge-shaped groove, the tensile load will cause the specimen to slide down along the inclined surface, thus becoming tighter as it is clamped.

Adaptation scenario: Suitable for thicker (>)3mm）、 High strength copper strips, or copper strip specimens with rectangular cross-sections.

Caution: Not suitable for ultra-thin copper foil, which may cause local stress concentration and premature fracture of the sample.

Automatic centering fixture

Structure: On the basis of the flat mouth fixture, a coaxiality calibration mechanism (such as guide rails, laser positioning devices) is added. During the clamping process, the position of the sample can be automatically adjusted to ensure that the axis of the sample coincides with the load axis of the testing machine.

Adaptation scenario: Suitable for high-precision testing scenarios (such as scientific research and development, material performance analysis), it can avoid distortion of test data caused by sample deviation.

Advantages: Eliminating the influence of bias load, significantly improving the testing accuracy of tensile strength, yield strength and other indicators.