PH Tool offers many different types of holes
used in NDE today. The popular ones are listed below. If you don't find
what you're looking for, call us and we'll be happy to discuss how it
can be done. We employ both conventional machining (drilling) and nonconventional
(EDM) in the hole-making process. The determining factors we consider
in choosing a method are machinability of the workpiece, accessibility,
hole diameter and depth.
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The flat-bottom hole (FBH) is machined
to have a flat reflecting surface at the hole bottom. The hole
bottom is typically parallel to the beam entry surface, but can
be machined at other desired angles. Primarily used in Ultrasonic
testing, with some application in Eddy Current testing, FBHs can
be machined just about anywhere they are needed for a particular
inspection. Available in diameters from .010". |
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The side-drilled hole (SDH) is typically
a drilled hole, the side wall of which is used as the reflecting
surface. Unlike the FBH, the bottom of a SDH serves no purpose.
SDHs are often reamed after initial drilling. SDHs are often drilled
in pipe walls at specified locations from the diameter, e.g.:
1/4T, 1/2T, and 3/4T. They can be drilled either longitudinally
or circumferentially to the axis of the pipe. They can also be
machined in plate, bar or other products. Primary use is Ultrasonic
testing. Available in diameters from .010". |
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The micro-sized hole (MSH) is a small
diameter hole used primarily in Liquid Penetrant inspection. Hole
diameter is normally 0.004 to 0.005", and hole depth is 0.008
to 0.010". These micro-sized holes meet the requirements of the
U.S. Navy's NSTR-99 Rev. 2 (Qualification Examination Requirements
for Nondestructive Test Personnel). They can be machined in welded
plate, pipe, bolts, or any test prop. Also available in diameters
and depths other than stated above. |
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| Concave
Radius-bottom hole |
The concave radius-bottom hole is machined
with a concave radius at the hole bottom. Applications include
ID pitting of tube or pipe for Eddy Current Inspection; and Liquid
Penetrant test props. Available in diameters from 0.004". |
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| Convex
Radius-bottom hole |
The convex radius-bottom hole is machined
with a convex radius at the hole bottom. Available in diameters
from 0.030". |
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These holes and pits are machined in
irregular configurations, not described above. Includes star-shaped,
square holes, hex holes, and realistic pits. EDM pit electrodes
can be cast from real pits and used to reproduce actual pits very
accurately. If you still haven't seen the hole you need, use your
imagination... we'll figure out how to accomplish it. |
Photograph showing a cast replica of an Irregular Pit machined by EDM into a turbine blade. Pit dimensions are .010” diameter x .020” deep. Any size and shape is possible.
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