ISO 12671-2021 pdf free download – Thermal spraying — Thermally sprayed coatings — Symbolic representation on drawings.
8 Instructions when using a separate parts’ list This clause applies when a component is represented by one or more drawings and a separate parts’ list. In such a case, the coating will be indicated on the drawing only by a position number (see Figure 6). Any instructions regarding the coating, such as the spraying process, coating thickness and its acceptable thickness deviation (especially if coatings consist of a bond and top coat), spray material, surface condition and post-treatments shall be defined in the parts’ list or by indicating a specific technical instruction (see Figure 6).
9 Instructions when the use of the spray process is protected by a patent If a coating process shall be applied but the use is protected by a patent (spraying procedure, spray material, process parameter, etc.), the trade name of this coating process may be indicated analogous to “Coating per special specification” (see Figure 7) as a supplementary symbol in the symbolic representation, or it may be defined via a position number in the pertinent parts’ list (see Figure 6).
10 Representation and dimensioning The area of a component to be coated shall be indicated by a broad dashed-dot-line outside the outline of the component on the drawing. Where necessary, the size and position of the range of coating shall be defined by means of dimensions and tolerances on the drawing. Areas that are allowed to be coated (e.g. outside the coating range) shall be indicated by a broad dashed line outside the component’s outline. Areas that are not accepted to be coated shall not be indicated (see Clause 11). The dimension that locates the coating in relation to the front face of the work piece shall appear on the drawing only. The dimensions of length and/or width shall appear on the drawing only. Whenever a post-treatment is applied, the indication of the roughness tolerances shall be mentioned corresponding to the pertinent standard on the drawing close to the dimension. Instructions regarding coating thickness or thickness of the bond and top coat are to be indicated together with further instructions in the symbolic representation or in the parts’ list. The coating thickness shall apply for the indicated condition (e.g. as = as sprayed, f = fused, m/c = machined, or in combination: f+m/c = fused and machined). If no further instructions about acceptable deviations of coating thickness are mentioned, the general tolerances shall apply.
11 Supplementary instructions Supplementary instructions may be necessary to define further particular characteristics by indicating them either in the symbolic representation or in a separate parts’ list. Instructions containing specific instructions for the execution of the preparation or spray procedure or thermal treatment or special sealing are preferably indicated behind the elementary symbol for the thermally sprayed coating with the pertinent specification number, or they will be indicated by their position number in the parts’ list (see Figure 7 and Table 1). For workshop drawings only, a remark for applying masking may be given by a specific sign on areas that are not allowed to be coated (see Figure 5). A remark restricting the acceptable deviations from the nominal thickness shall be added to the coating thickness on the drawing, in the parts’ list or as part of an individual specification.
12 Examples Figures 2 to 6 show examples of the symbolic representation of thermally sprayed coatings. Figure 7 shows the designation for a thermally sprayed coating by using a position number. The technical instructions for the thermally sprayed coating shall be defined in the parts’ list.ISO 12671 pdf download.