SAE AS 478P:2017 – ldentification Marking Methods
SAE AS 478P:2017 – ldentification Marking Methods.
Where two or more locations for marking are specified. markings shall be grouped so that as few of the locations as practicable are used.
3.2 Permanent Markings
Permanent markings are permitted on finished items only when specified on the engineering drawing from which the item Is manufactured.
3.2.1 Items which require more than one identification number, such as item number, serial number. etc.. shall have each number on a separate line; or consecutive identification numbers on the same line shall be separated by no less than two spaces. The separation or division of the digits of an identification number will not be objectionable provided the digits are in sequence and cannot be misread.
3.22 Permanent marking for the general Categories of items shall normally be between 0.060 and 0.160 inch (1.5 and
4mm) in height. In special cases when governed by size or configuration. 0.016 inch (0.4 mm) minimum or
0.250 inch (6.35 mm) maximum height is permissible, or as otherwise specified in this standard or on the item drawing. When integral marking Is used, the height should not exceed 0.500 inch (12.7 mm) nominal character size.
3.2.3 Permanent marking is not recommended on contacting surfaces, nor on surfaces which are in motion with respect to the mating surface during operation of the items. However, when permanent markings must be placed on such surfaces, all raised metal and burrs shall be removed in accordance with the requirements given on the item drawing.
32.4 Permanent markings shall not be applied on surfaces which have been chemically processed, painted, or plated unless the marking will be legible and the minimum requirements of the surface treatment process is maintained o restored.
3.2.5 Permanent markings shall not be nearer than 0.031 inch (0.78 mm) to any corner, fillet, or edge unless spedfically designated. Where a specific marking location, as designated and dimensioned, does not provide enough area for 0.031 inch (0.78 mm) distance to any edge, corner, or fillet, the markings shall be centered upon the area without breaking over an edge or encroaching into corners or fillets. When parts are machined from previously marked hexagon bar stock, the 0.03 1 inch (0.78 mm) edge restriction is waived, provided the marking is legible.
Stress concentrations resulting from improper applications of marking methods may cause item distortion or failure. Marking methods, such as methods 4 or 6 in Table 1, may produce secondary effects which are detrimental to item reliability and must be properly evaluated to the item design. Items distorted or otherwise damaged by marking shall be subject to rejection. Permanent markings not in compliance with the limits given in this standard may be the basis for rejection of the items by the purchaser.
Identification marking shall be legible and make full use of the available marking area. Characters shall be block form capital letters and Arabic numerals without serif s. such as Gothic or Futura.” Lower case letters may be used when required for metric unit symbols. Other characters shall be of similar appearance. Condensed letlers and smeared letters shall be cause for rejection. Templates for the electrochemical process may be produced by a conventional typewriter provided legibility is maintained. Processes performed after marking which may reduce legibility (such as vapor or grit blasting, tumbling, etching, etc.) shall be controlled to prevent loss of legibility. Normally all characters shall be legible without magnification. However, where space or surface condition limits the size of characters that may be used. legibility with 3X magnification maximum is permissible when authorized.
3.2.8 Optical Character Recognition (OCR)
Marking requirements for the standard OCR-A character set are specified in ANSI INCITS 17. The OCR-A marking character’s height, width, spacing and positioning requirements are specified in Table 2. See 6.1-1 for an example of designating OCR font marking method.