I happen to have my “History of Torture” by Brian Innes handy (cleaning out some books).
Here’s what it has to say on pg 21:
“The Roman flogging whip, the flagellum, was feared by all. It’s thongs, made of ox-leather and sometimes weighted with lead, could cut deep into the flesh. According to Horace, certain judges were so sadistic that they ordered whippings of such length that the executioner was forced to desist, from sheer exhaustion, before the sentence was completed. Many Roman slaves died in the course of their flogging. Lesser penalties were carried out with the scutica, a whip with thongs of parchment, or the ferula, a flat leather strap.”
It should also be noted that the only thing the Bible tells us Jesus Christ made, carpenter’s son that he was, was a whip. (Scifi author and Catholic Gene Wolfe pointed this out in an interview).