Part Marking Specifications

PS-00200 Marking of Military Ground Support Equipment Parts

This specification covers the requirements for marking of aerospace ground support equipment parts and is applicable unless otherwise directed by the customer or contract.

1.1 Exceptions
1.1.1 Undefined Marking Class on Drawing
In the event a drawing does not reference this Process Specification for part marking, it shall be inferred that this document is the guideline by which part marking definition shall be determined. Class 2A ink stamp marking (Ref. shall be considered to be the preferred method of marking unless there is reason the part cannot be marked in this manner.

1.1.2 Undefined Marking Location on Drawing
In the event a supplier is assembling and delivering multiple parts (which each make reference to a part marking procedure on the individual part drawings) as a single assembly, only the assembly number being delivered is required to be marked on the assembly. Furthermore it should be noted that all parts should be marked on the back surface of the part and it should be inferred that the main view of the drawing is the front surface of the part, unless otherwise noted on the drawing.

The following publications shall be applicable to the extent specified herein, or as defined on the contract or purchase order. These publications shall be in effect as of the issues listed. Compliance with any other issues of these publications requires prior written approval from ITW Military GSE. Insofar as any of the publications referred to herein conflict with the requirements of this specification, this specification shall govern.

2.1 Federal Documents
Available from DODSSP Subscriptions Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, Pennsylvania 19111-5094, U.S.A.

  • A-A-208 Ink, Marking, Stencil, Opaque
  • QQ-A-250/4 Aluminum Alloy 2024, Plate and Sheet
  • TT-I-735 Isopropyl Alcohol
  • Fed-Std-595 Colors used in Government Procurement

2.2 Military Documents
Available from DODSSP Subscriptions Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, Pennsylvania 19111-5094, U.S.A.

  • MIL-M-43719 Marking Materials and Markers, Adhesive, Elastomeric, Pigmented; General Specification for
  • MIL-C-83286 Coating Urethane, For Aerospace Application
  • MIL-C-85285 Coating Polyurethane, High Solids
  • MIL-PRF-83282 Hydraulic Fluid, Fire Resistant Synthetic Hydrocarbon Base, Metric, NATO Code Number H-537
  • MIL-STD-130 Identification Marking of U.S. Military Property


3.1 Marking Requirements
Parts shall be individually marked with the applicable cage code identification, a slash and identifying number. In addition the revision level designator that the part(s) were fabricated to shall be placed adjacent to the identifying number. Parts in assemblies that are not normally subject to disassembly or repair, that is welded, riveted, brazed, cemented, or bonded, do not require individual marking. In addition, the calendar date of manufacture or other pertinent manufacturing information shall be applied if indicated on the engineering drawing or specification control drawing. The marking may be one or more lines.

3.1.1 Part Identification Marking
Part number markings shall be of the class specified, placed at the location indicated and constructed in accordance with the detail callout of the engineering drawing. When the location is not identified on the drawing the marking location is optional and shall comply with the requirements of this specification.

  • For example:
    (a) The drawing callout, “PLACE PART NO. HERE,” indicates a requirement to construct the part identification number as shown below:
  • For Example:
    Cage Code Identification Number (Trilectron/ITW Military GSE)
    A Separation Symbol
    Part Identification Number
    Revision designator
    12867 / 24567 REV A

3.1.2 Methods of applying
Marking shall be per the Class, and letter designation (if any), noted on the engineering drawing. Approved alternates are listed in this specification. When a letter designation is not shown, any method within that Class may be used as long as the marking complies with the requirements of this specification. Approved alternates are listed in this specification.

3.1.3 Insufficient Surface
When parts do not have a suitable surface or area on which the number can be placed, the parts are to be tagged per Class 2D or placed in marked containers per Class 2E.

3.1.4 Permanency and legibility
The markings classified in this specification shall remain legible and be as permanent as the normal life expectancy of the item on, or to which, it is applied. The markings shall be capable of withstanding the environment specified for the item. The color of the marking shall contrast with the surface color of the item.
3.1.5 Markings exposed to fuel
Markings that will be exposed to fuel shall be marked per one of the following methods. Requirements for these methods will be called out on the engineering drawing. Parts coated with MIL-C-27725
Use Class 2A, 2B, 2F, or 2G markings. These markings may be applied before the coating only if the marking is clearly legible after coating application, or the marking may be applied after the final coating. Protective coating over the marking is optional. Parts with anodized finish
Use Class 2A, 2B, 2F, or 2G markings. These markings shall be applied after anodize. Protective coating over the marking is optional. All other parts
Use Class 2A, 2B, 2F, or 2G markings. These markings shall be protected by coating with MIL-C-27725. Markings must be clearly visible after application of the protective coating.

3.2 Part or dash number changes
In all instances when an item is altered in conjunction with an engineering change and a new part or dash number is required, the old part or dash number and manufacture date shall be obliterated without damage to the part and the new part or dash number and manufacturing date applied. Both obliteration and re-identification shall be accomplished in the same manner as specified on the drawing unless otherwise specified by the engineering documentation initiating the change

3.3 Marking Methods

3.3.1 Class 1 Markings Class 1A—Vibroengraving
For Class 1A marking, an electric or air vibrating tool equipped with a special hardened steel or synthetic engraving needle shall be used to produce an indented marking. The minimum spherical radius of the engraving tool point shall be 0.007 inch. The impression depth of the markings shall not exceed 0.003 inch on material thicknesses of 0.040 inch or less, or 0.005 inch on material greater than 0.040 inch. Vibroengraving shall be applied prior to the application of protective finishes such as chemical film, anodize, primer or paint. Class 1B—Electro-Etch
For Class 1B markings, an electrolytic stamping unit equipped with a transfer stencil and an ACDC transformer shall be used to produce an etched marking. Electro-etch markings shall not be applied to steel parts with a tensile strength above 180,000 psi. Class 1C—Acid Etching Ink
For Class 1C markings, an acid-type etching ink shall be used to produce an etched marking. The process must include neutralization of acid with a mild solution of ammonium hydroxide or sodium bicarbonate, followed by rinsing the area with water to remove the acid.

3.3.2 Class 2 Markings
Class 2A rubber stamp, Class 2B stencil, Class 2F hand lettering, or Class 2G Automated marking may be used as alternates. Class 2C, decal, may also be used for marking manufacturing serial numbers on printed circuit assemblies. Class 2A Rubber Stamp
For Class 2A markings, a rubber stamp shall be pressed onto an ink pad and the ink transferred
to the part surface. Class 2B Stencil
For Class 2B markings, a paper, plastic, or metal stencil and MIL-C-22750 paint or A-A-208 stencil ink shall be applied by brush or spray gun.

  1. Unless otherwise specified on the drawing, when MIL-C-22750 paint is used, it shall be black epoxy paint, Color 37038, per Fed-Std-595 unless the background is black. In such instances it shall be white, color 17875 or 17925.
  2. When A-A-208 stencil ink is used, it may be applied by stencil techniques or by rubber stamping from an ink pad containing the A-A-208 ink. NOTE: Class 2G Automated marking may be substituted for Class 2B markings on tubing and tubing assemblies. Where the engineering drawing calls out Class 2B markings for Reference Designators. Class 2C Decalcomanias (Decals)
For Class 2C markings, a plastic film or other transfer medium shall be printed and applied to the part surface in accordance with MIL-M-43719. Decals shall not be applied in plenum chambers or air flow passages. Class 2D Tagging
For Class 2D markings, a metal, paper, or plastic tag shall be attached to the part using nondestructive methods. Tag markings shall not be applied in plenum chambers or air flow passages. Class 2E Marked Containers
For Class 2E markings, parts shall be placed into a paper bag, plastic bag, or other suitable container. The marking information shall be applied to the exterior surface of the container or to a tag attached securely to the container. Class 2F Hand Lettering
For Class 2F markings, parts shall be legibly marked free hand using ink per A-A-208 or any of the products approved by ITW Military GSE Engineering prior to application. Class 2G Automated Marking
For Class 2G markings, use an automated system approved by ITW Military GSE Engineering prior to application. Class 2H Marking Plates, Self-Adhesive
For Class 2H markings, in-house marking may be accomplished utilizing metal stamping methods including typewriter, as appropriate for application. Self Adhesive Marking Plates markings shall not be applied in plenum chambers or airflow passages. Class 2J Hot Stamp Foil
For Class 2J markings a hot stamp foil-marking machine shall be used. The machine and the foil shall be from a source approved for use at the using facility. Hot stamp foil markings are for heat shrink tubing only.

3.4 Application of Marking
3.4.1 In-process identification, inspection, and non-drawing-required markings shall be applied per Class 2. Class 1 markings may be used only when specifically authorized by a Class 1 marking callout on the drawing. The location of these markings is optional unless otherwise noted on the drawing. The markings shall not be applied on surfaces that form the exterior of the airplane when in flight with landing gear up. Exterior primed surfaces may be marked with a temporary method of marking which can be removed during the preparation for final finishing, or is covered by final finish. Components installed in the crew compartment shall be marked in such a manner that the marking is not visible to the crew members.

3.4.2 Lettering
Lettering of markings shall approximate Futura Medium Capital or Sans-Serif Gothic Capitals. Only Arabic numerals shall be used.

3.4.3 Sequence (Stage) of marking
Class 2A, Class 2B, Class 2F or Class 2G markings required per 3.1.1 shall be applied as shown below. The final finish determines the finish and marking sequence.

(1) MIL-C-85285 Urethane topcoat – mark after application of the topcoat.

Other classes of markings shall be applied to the part at an appropriate stage of manufacture.

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