
Most airliners autoflight system won't allow steeper banks than 30 degrees.
However...steep turns are more common than you think, it's just that pilots are proffessionals and performs these manoevers without you even notice it.
just as an example: Some approaches to Heathrow calls for a good 150 degree turn (change in direction, not bank angle, lol) and those my friend can be quite steep - even in the 737's it's common to see them go into excessive