In the fields of electronics, electrical engineering, and communications, terminal blocks play a key role as important connection components. Whether in industrial equipment, household appliances, or electronic devices, terminal blocks must ensure that connections are secure and reliable to guarantee the transmission of electrical power or signals. In this context, the tensile strength retention test for terminal blocks has become an indispensable method for evaluating their quality and performance.

A tensile strength or pull test actually means to hold a crimped connection steadily and apply a force to it. The tension test for wire cable lugs is a critical process to ensure the integrity and reliability of the connections. It involves applying a force to the crimped joint to determine its tensile strength.

Several international and industry test standards specify test methods, with little variation in their parameters other than definitions of acceptable load bearing. Those in aerospace or military application are expected to be exceptionally robust. Originally, testing was done by hanging calibrated masses from wires that were gripped by their terminals, but this is slow, cumbersome, and less than precise. Instead, forces are applied by hand lever against a calibrated loadcell, or better, pulled at a known constant speed by motor control.

Test type: 

1, Pull and Return

A non-destructive test whereby the terminal is pulled to a specified force and then the force is removed.

2, Pull and Hold

A non-destructive test whereby the terminal is pulled to a specified force and held for a specified period of time. The force is then decreased to zero.

3, Pull, Hold and Break

A destructive test whereby the terminal is pulled to a specified force and held for a specified period of time. It is then pulled further until either the terminal and wire separate or the wire breaks.

Clamping of the wire terminal: 

The simplest assembly terminal for clamping consists of a wire and a pointed or ring connector, but there are many customization requirements, such as angle rings and side markings. In this case, custom fixtures are needed to apply axial pulling force to the conductor in order to grip the biased connector. The fixture must fit the type of terminal to ensure that they are secured without slippage and do not deform the terminal. Many fixtures can be placed in a notch to allow narrower wires to pass through while applying pressure to the terminal barrel. Similarly, when gripping the tail of the insulated conductor, the fixture must not bite or weaken the copper or aluminum conductor, nor should it clamp the insulation too loosely to prevent slipping and stretching.

Specification: