  We report that high transport critical current density exceeding 104 A/cm2 at
4.2 K and 10 T can be obtained with good reproducibility for Ag sheathed
(Ba,K)Fe2As2 (Ba 122) tapes by modifying the ex-situ powder-in-tube (PIT)
method. The process involves cycles of the cold deformation and subsequent heat
treatment. The intermediate cycles of flat rolling and heat treatment produce
uniform fine-grained structure, resulting in an enhancement of transport Jc in
applied magnetic fields. However, the rolled tapes contain cracks running
traverse to the tape axis, which still limit the current pass along the tape
axis. We found that the application of uniaxial pressing with small reduction
rate at the final stage is very effective to heal those cracks, resulting in an
extraordinary increase of the transport Jc. We achieved the highest Jc (at 4.2
K and 10 T) of 2.1x104 A/cm2 among the PIT processed Fe based wires and tapes
reported so far. The Jc-H curves measured at higher temperatures maintains a
small filed dependence up to around 20 K, suggesting that the tapes are
promising for applications at higher temperatures as well as in liquid helium.
