In the case of the B (or center) pillar on four-door sedans, the pillar is typically a closed steel structure welded at the bottom to the car's rocker panel and floorpan, as well as on the top to the roof rail or panel.
On an average a period lasts between 3 to 5 days. It is normal for a girl to have irregular periods in the beginning. During this time, the duration of her periods may vary from as short as 2 days to as long as 7 days. It can take up to a year for periods to become regular.
Periods usually last anywhere from eight to ten days and this is generally normal for most women. Some women have periods for as short as 3 days and sometimes longer than 7 days. A period that last longer than that is abnormal and is concerning.