What variety are they? you may need a pollinator. Did they blossom this year? Check a list of apples types for compatible pollinating.

If you know the names of your apples Egrow, type in the name +pollinator and you will see if they are not being pollinated. Sometimes you get a tree that is a dud, though it seems strange to have 3 blind trees. If you have several trees, as we have done, on limiting rootstock, for at least 40 years, they do vary a lot in fruiting ability. Over the years we have taken out a lot of trees for underperformance.