Do not select the database ... mysql_select_db () expects parameter 1 to be string [closed]

<div class="columnader">
        <?php
        session_start();
        $servidor="localhost";
        $usuario="root";
        $pass="";
        $based="pruebastarento";
        $conser=mysql_connect($servidor, $usuario, $pass);
        $conbd=mysql_select_db($conser,"pruebastarento") or die (mysql_error());


        $cadena="SELECT * FROM 'tornillos'";
        $run=mysqli_query($conser,$cadena);

        echo"<TABLE id='tlista'>";

        echo"<tr>";
        echo"<th> ID </th>";
        echo"<th> Nombre </th>";
        echo"<th> Tipo </th>";
        echo"<th> Descripcion </th>";
        echo"</tr>";

        echo"<tr scope='col'>";
        echo"<p>";

        while($fila = mysqli_fetch_array($run,MYSQL_ASSOC))
        {
             echo"<TR align=center>";
             echo"<TD>".$fila['ID_TOR']."</TD>";
             echo"<TD>".$fila['NOM_TOR']."</TD>";
             echo"<TD>".$fila['TIPO_TOR']."</TD>";
             echo"<TD>".$fila['DESC_TOR']."</TD>";
             echo"</TR>";
        }
        echo "</p>";
        echo "</tr>";

        mysqli_close($conser);

        echo"</TABLE>";

        ?>