It's probably wire wrapped Ron very common back then,which affords a surprisingly good grip when wet/sweaty I have no idea how or why that should be but it works
Steve
Well they would have course worn gloves/gauntlets and have callouses like nobodies business which would help and I'm sure they would have people on hand to repair them, also the chances of the hilt being damaged without causing a serious injury to the hand/arm wielding it would be fairly low speaking from personal and painful experience fingers are usually the first to get battered if a sword is hit in that area rather than the weapon