  The regular behavior of the pulsations of high-amplitude Delta Sct (HADS)
stars gives a greater chance to investigate the interiors of stars. We analyzed
seven HADS stars showing peak-to-peak amplitudes of more than 0.3 mag that were
newly observed by TESS. We obtained that TIC374753270, TIC710783, and
TIC187386415 pulsate in fundamental radial mode, also, TIC130474019 and
TIC160120432 show double radial modes. On the other hand, TIC148357344 and TIC
278119167 demonstrate triple-mode behavior. Our analysis shows that these seven
stars are close to the red edge of the (inside) instability strip in the
Hertzsprung Russell diagram. The fundamental mode of these seven targets
follows the period-luminosity (PL) relation for Delta Sct stars. However,
TIC278119167 deviates slightly from the fundamental PL relation. The
double-mode and triple-mode HADS stars (TIC130474019, TIC160120432,
TIC148357344, and TIC278119167) are in agreement with the period ratio ranges
(fundamental to first and second overtones). Using the information of 176 HADS
stars (Netzel and Smolec), we find a scaling relation ([Fe/H]
~log((M**7.95+-0.15)(L**-1.83+-0.11)(P0**0.79+-0.14)(Teff**0.047+-0.02)))
between the metallicity ([Fe/H]) and mass (M), luminosity (L), effective
temperature (Teff), and the fundamental period (P0). We estimate the
metallicity of the seven newly identified HADS stars ranging from -0.62 to 0.37
dex.
