blind drilling

blind drilling

[′blīnd ′dril·iŋ]
(engineering)
Drilling in which the drilling fluid is not returned to the surface.
References in periodicals archive ?
However, a major obstacle to acceptance of blind drilling by the mining industry has been the lack of precise hole verticality needed for hoisting operations.
Components feature a large number of machined holes, blind drillings and galleries which need to be thoroughly cleaned to optimise performance.