MIL-HDBK-115 Us Army Reverse Engineering Handbook Guidelines And ProceduresThis HANDBOOK, which provides the guidelines and procedures for performing reverse engineering, was created using current applicable laws and knowledge gained during a trial program from July 1985 to April 1987, and is based on experiences obtained from military and industry participants. This handbook is for guidance only and cannot be cited as a requirement.

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MIL-HDBK-115B(ARMY)

manufacturer will intentionally punch a hole with a minimum clearance between the punch and the die. This is done to create a larger "straight land" in the hole, which may be required as a load bearing surface or to minimize wear on mating parts. When reverse engineering a punched hole, the "land- width" should be noted.  If it is more than 25% of the length of the hole, it could be intentional.

(2) In addition to the draft and parting lines, ejection-pin locations should be included in the final drawing.

g. Joining methods such as riveting or spot-welding may require testing to determine the strength requirements. Many spot-welded items are controlled at the weld by pull-tests. If necessary, applicable specifications should be reviewed for inclusion in the final TDP.

h. Heat treatment should be evaluated, using cross sections as required to determine case depth, grain structure and other metallurgical requirements. Grain flow on forgings should be noted.

i. Whenever a pressed-in bushing exists, concentricity of that bushing to the diameter securing it should be ensured.

j. If dowel pins are used to align mating parts, the location of the pins at the projected distance should be ensured to assure the fit of those parts.

k. Surface finishes on all mating surfaces should be checked, whether or not a gasket is used.

l. Casting surfaces subject to wear for grain structure variances caused by special casting processes should be examined using chills to "harden" the casting in that particular area.

m. Electrical wire diameters should be measured and insulation type and thickness noted. The length of the wire should be duplicated even if it appears to be excessive. Shortening a wire length could change the electrical characteristics of the end item.

5.21.3 Process variation. A manufacturing process variation can produce some strange numbers for part or assembly dimensions. Unless the dimensions or specifications for the next higher assembly are known, "normalizing" of interface dimensions is not recommended.

5.21.4 Establish tolerances. If possible, dimensional analyses should be performed on not less than two items. The results of each may then be compared to determine the possible existence of manufacturing variances as

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