may i throw in a different approach?
I guess these bolts are not there to take any forces but just to position the wedge. So it might be worth checking if the wedge or ram are not worn out somewhere an add some material/ make repair if necessary.
IF my thinking is correct you dont want these bolts to take the pressure as they will break again and can become lethal projectiles.
Contrary to the shear bolt on a flail or other implement, where they are put there to define a weakest point in the driveline, i dont see why you would put them on a splitting wedge. Besides, shear bolts are used by piece, can be multiple bolts in line along the driveline but never as pairs (so 2 bolts taking the strain) you can define 1 breaking point but not 2.
Dont know if the last is clear enough but forget the idea of 2x 1 ton shear bolts gives a strenght of 2 ton. The weakest point will break = 1 of both = 1 ton.
just my 2 cents