MIL-DTL-44117B
shall not be acceptable. Rework on these items to repair delamination and blistering shall not be
permitted or authorized.
3.6.1.3 Holes for attachment of components. Holes for attaching the helmet components shall
be drilled in accordance with the dimensional requirements of Drawing 8-2-830; this shall be
accomplished before finishing. There shall be no delamination of the shell material greater than
0.125 inch as a result of the drilling operation.
3.6.2 Stitching. All stitching be in accordance with ASTM D 6193 and shall be as specified in
Drawing 8-2-602 and as specified in 3.6.3, 3.6.4, 3.6.5, and 3.6.6.
3.6.3 Type 301 stitching. Unless otherwise specified, ends of all stitching shall be backstitched
or overstitched 1/2 inch minimum, except where ends are turned under in a hem or held down by
other stitching. Thread tension shall be maintained so that there will be no loose stitching resulting
in loose bobbin or top thread, or no excessively tight stitching resulting in puckering of the sewn
materials. The bottom and top thread interlock shall be embedded in the sewn materials.
3.6.3.1 Repairs of type 301 stitching. Repairs of type 301 stitching shall be as follows:
a. When a thread break or bobbin run-out occurs during sewing, the stitching shall be repaired
by restarting the stitching a minimum of 1/2 inch back from the end of the stitching. 1/
b. Any thread break, or two or more consecutive skipped or run-off stitches noted during
inspection of the item (in-process, or end item) shall be repaired by overstitching. The stitching
shall start a minimum of 1/2 inch in back of the defective area, continue over the defective area,
and continue a minimum of 1/2 inch beyond the defective area onto the existing stitching. Loose
or excessively tight stitching shall be repaired by removing the defective stitching, without
damaging the materials, and re-stitching in the required manner.1/
1/ When making the above repairs, the ends of the stitching are not required to be backstitched.
3.6.4 Bartacking. Unless otherwise specified, bartacks, if used, shall be 3/4 (±1/16) inch long,
1/8 (±1/32) inch wide, and contain 42 stitches per bartack. Bartacking shall be free of thread
breaks and loose stitching.
3.6.5 Automatic stitching. Automatic stitching machines may be used to perform any of the
required stitch patterns provided the requirements for the stitch pattern, stitches per inch, size and
type of thread are met; and at least three or more tying, overlapping, or back stitches are used to
secure the ends of the stitching.
3.6.6 Thread ends. All thread ends shall be trimmed to a length of not more than 1/4 inch.
3.6.7 Setting of snap fasteners. On all textile and leather components, the holes punched
before inserting the male or female part of the snap fasteners shall be smaller than the outside
diameter of the fastener barrel so that the barrel must be forced through the hole. The fasteners
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