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|  MIL-E-22200G
4.6.2 Procedure for measurement of concentricity, diameter and length.
4.6.2.1 Concentricity preparation. Each electrode required by 4.5.2 shall
be prepared for concentricity measurements in accordance with the procedure
below:
(a) The covering shall be removed to bare metal at three places; that
is near both ends and near the mid-length of the electrode.
(b) Care shall be taken not to remove any metal.
(c) The covering shall be removed at each location in the form of a
groove 1/2 inch minus 0, plus 1/4 inch wide for 360 degrees
around the electrode.
(d) The side walls of the groove may be gradually sloped to a maximum
width of 1 inch at the outside surface of the covering.
4.6.2.2 Concentricity measurements. Measurement of the prepared electrode
shall be made with the aid of a supplemental piece of 1/4 by 1/4-inch key stock
(or equal) 2
1/16 inches long. The key stock shall be placed symmetrically
across the groove and, using any appropriate measuring instrument, the core wire
diameter plus the thickness of the cover on one side of the electrode plus the
thickness of the key stock shall be measured. For instruments using a base for
zero reference, the base where it is in contact with the electrode during
measurement shall be 2
1/16 inches wide and symmetrical about the groove in the
electrode covering. The maximum and minimum dimensions shall be located for each
groove of each electrode in the sample measured to the nearest 0.001 inch and
recorded.
The maximum and minimum pair of dimensions which show the greatest
difference for the electrodes required to be measured by 4.5.2 shall be used to
determine conformance to the requirements of 3.5.2.
4.6.2.3 Diameter and length of core wire.
Each electrode required by 4.4.8
shall be measured for diameter and length for conformance to the requirements of
3.6.1.
4.6.3 Dielectric strength. Dielectric strength of coverings shall be
determined by the method shown on figure 1. Methods other than the one shown,
yielding the required results, may be used as alternates if such methods are
acceptable to the Government.
4.6.4 Flaking and cracking of covering. When required by the applicable
detail specification, six electrodes shall be tested for flaking and cracking
tendency upon restarting and during welding in accordance with 4.6.4.1 and
4.6.4.2, respectively. The polarity shall be the same as required by the detail
specification for the MIL-type electrode being tested. The welding current used
shall be in the same range as required by the applicable detail specification for
groove welds. The welding shall consist of depositing a bead weld on the plate
surface.
4.6.4.1 Flaking and cracking upon restart. Three electrodes shall be
tested. The covering shall be grooved to the core wire completely around the
electrode at the midpoint of the length. The groove shall be prepared by
grinding with the edge of a grind stone (intersection of flat side of grind stone
with its periphery). The core wire shall be uncovered at the root of the groove
to form a land 1/16 inch minimum along the length of the electrode. The core
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