Section 10: Basic and common symbols recognition PURPOSE This section aims to enable the student to extend their knowledge of Drawing Interpretation from Engineering Drawings produced to AS1100 standard. Objectives At the end of this section you should be able to: o Interpret information on detail drawings of engineering components. Completion guidance Students should attempt this section if the material relates to the engineering discipline they are employed or intend to be employed in. MEC076 Engineering Drawing Interpretation 1 Resource Package h'" iI 'II I MEC076 - 10 - 1 I December, 1998 131 Basic and Common Symbols. Recognition. The symbols covered in on the following pages are an example of the widespread use of symbols and abbreviations in industry. The symbols and abbreviations covered in this module relate to a few trades and professions. In some areas there are so many symbols and abbreviations that only someone who is heavily involved would know them all. If you do not know what a symbol means, do not guess, because in some industries it could lead to a serious injury or death if a wrong interpretation or decision is made. If you do not know what a 1126.50 I symbol means, make sure you ask someone who definitely knows, not someone who does not Feature like to admit that they do not know. You do not want the guess of someone else, you want identification someone who definitely knows or someone who has the latest publication containing the symbols. A Datum identification R8 Radius R 135 R12 1:-·;·-:1 Equal .015 ~ Diameter First angle projection .08 ~D65 Third angle projection Square D -C-----} -8:-1:4 Taper t::::". 1: 3.5 Slope MEC076 Engineering Drawing Interpretation 1 Resource Package ti " iii 'II [ MEC076 - 10 - 2 I December, 1998 132 Surface textures Adding the roughness value to a standard symbol Surface texture Surface texture refers to the roughness of a surface. It can vary from very rough to very II If a particular surface finish is required, but the production technique is not smooth, for example an aluminium casting may have the following surface textures: important, this symbol should be used: \y II rough cast .. If a particular surface finish is required by using a machining operation, this symbol II fine cast would be used: 7' II die cast .. When a surface finish is needed on a surface where no material can be removed, this II rough machined symbol would be used: V~ II medium machined II fine machined Standard symbols V Basic symbol: used when surface finish can be produced by any convenient technique. ~ Modified symbol: finish done by a machining process. \! Modified symbol: indicating a surface finish without removal of material (for example, quality of an initial casting). Roughness value chart -:>'"3:_ >,:;< ' A""",",L \'//' 50 Rough oxy cut 25 Rough casting 12.5 Rough machining 6.3 Course machining 3.2 Average machining 1.6 Good machining 0.8 Fine machining 0.4 Fine grinding 0.2 Honing 0.1 Buffing 0.05 Polishing 0.025 Super polishing These numbers will become more relevant when the user is more conversant with the finishes they represent. Ask your teacher to supply samples of various finishes to a certain roughness value. MEC076 Engineering Drawing Interpretation 1 Resource Package fi " iii 'II [ MEC076 - 10 - 3 [ December, 1998 133 Variations to standard symbols 2 3 4 DO NOT SCALE 3.2 These symbols show maximum and minimum ~~/ g:!/ A A roughness values. V V _-t----+~M"-1'-"2 " 1.75 20 60 I I Special surface characteristics are shown o ID ~ L..lL.i...1!",," ____-J. _____ ,--------- -----; J_j here. 0 May be added to a drawing in a note form or I ----""'-l-----lfl-I-~ ,-,--+-r-------+~-- _ _W I B B inserted into the title block. This one is used when all the surfaces are to be machined to M20 x 2.5 I .016 the same surface texture. 8 ALL OVER EXCEPT • WHERE OTHERWISE May be added to a drawing in a note form or # 51.... 1ED inserted into the title block, when a single surface texture value applies to most c c surfaces. Exceptions should be indicated on the surfaces concerned. Indicates that an allowance of 3mm is to be Y///////l~ provided for final machining. R15 o o Location of symbols on a drawing Section A-A Symbols may be located on an outline, projection line or leader line, provided that they can be th 'Md from th, bototom 0' d,ht h""~ ' dca"'f-~_g._____ ~ Olmen!Slons In mllllmetres 7 Fillet radii R3 min Threads to AS 1275 LJ.035 ;j; 2 E E "\ .024 r-.. Vle:w on arrow B - ---_':':-_--- - SAMPLE DRAWING SHOWING SURFACE FINISH SYMBOLS 6 ~"\ "\ !------I._. ~ I. Correct Incorrect MEC076 Engineering Drawing Interpretation 1 Resource Package hfUJ MEC076 - 10 - December, 1998 134 41 Basic Symbols for Arc and Gas Welding Reference code 1. Symbols for Welding No AS 26 2. Standards Association of Australia code for welding in building No AS 1554 Part 1 Butt welds Full penetration butt weld by a General butt welding procedure to be agreed z \ c/; Square butt II Flush \ h Single V butt v Convex Single bevel butt v Concave Single U butt Single J butt MEC076 Engineering Drawing Interpretation 1 Resource Package h"4:n MEC076 - 10 - December, 1998 135 51 Structural Steel Profiles and Welding Symbols The purpose of this page is to introduce you to some other symbols and abbreviations that are quite common on engineering drawings. Structural steel profiles are not drawn in most cases, nor are welds drawn or sketched as shown on the next page. These are only a few of the total number of symbol and abbreviations available in each area, and are produced here to make you aware of what area of engineering the symbols and abbreviations belong to. 200 UB 25 150 x 150 x 5 SHS where Square hollow 150 x 75 x 5 RHS Universal beam D[I UB SHS 200 D (nominal) section or where Depth greater = D[Gt or than width. 25 in Kg/m rectangular hollow 150 = D = mass ~ RHS section 75 = B 200 UC52 5 = t where Universal column D[I UC 75 ODx5 CHS Depth slightly 200 = D (nominal) greater than width. 52 in Kg/m Circular hollow where = mass CHS section dIG--t 75 = outside diameter 'd' 250 UBP 62 5 = t D[I where Universal bearing pile UBP Depth slightly 250 = D(nominal) 20RD L less than width. 62 mass Kg/m Round bar or rod d • RD where = I 2 = d 102 x 51 x 10 [ where L 20SQ Channel D[[ [ 102 = D Square bar DIll SQ where JBL --I BI-- 51 = B 20 = DorB 10 mass Kg/m = Flat 127x 75 x10 L a)bar or a)FL 150 x 8 FL where b)plate b)PL where Angle t D:B:. L 127 = D (plate 900 to 3200 rll or 150 = W equal and unequal W --IBI-- 75 = B in 100mm FL 8 = t 10 = t increments) MEC076 Engineering Drawing Interpretation 1 Resource Package fi lUI 1 MEC076 - 10 - 61 December, 1998 136 Sample of Welding Symbols as They Would Appear on a Drawing [7 10 10_• • MEC076 Engineering Drawing Interpretation 1 "1;1 j Resource Package 1 MEC076 - 10 - 71 December, 1998 137 Standard abbreviations Refer to AS 1100 for the full I H modulus of inertia mounting MIG A countersink CSK head HD mushroom head MUSH HD across flats AF countersunk head CSKHD height HT addendum ADD cross-recess head C REC HD hexagon HEX HEX HD N approximate APPROX cup head CUPHD hexagon head negative NEG arrangement ARRGT cylinder CYL hexagon-socket head HEX SOC HD assembly ASSY high strength HS nominal NOM NS automatic AUTO D high-tensile steel HTS nominal size NTS auxiliary AUX dedendum DED horizontal HORIZ not to scale number NO average AVG detail DET diagonal DIAG B diagram DIAG inside diameter ID P PAR bearing BRG diameter DIA internal INT parallel PT bottom BOT dimension DIM part PATT bracket BRKT distance DIST J pattern P brass BRS drawing DRW/DRG jOint JT pipe building BLDG junction JUNC pipeline PL PCD E pitch-circle diameter PH BRZ C elevation ELEV L phosphor bronze capacity CAP external EXT least material condition LMC plate pi cast iron CI left hand LH position POSN POS cast steel CS F length LG positive PREFAB centre line CL figure FIG longitudinal LONG prefabricated PRESS centre-to-centre, centres CRS fillister head FILL HD pressure PA chamfer CHAM flange FLG M pressure angle channel CHNL flat FL machine MACH or MIC cheese head CH HD malleable iron MI Q QTY chrome plated CP G material MATL quantity circle CIRC galvanise GALV maximum MAX R circular hollow section CHS galvanised iron GI maximum material radius RAD circumference CIRC galvanised iron-pipe GIP condition MMC raised countersunk head RSDCSK HD cold-rolled, steel CRS general arrangement GA mechanical MECH mild steel MS rectangular RECT computer-aided design and general-purpose outlet GPO rectangular hollow section RHS drafting CAD geometric reference frame GRF minimum MIN reference REF computer-aided grade GR modification MOD regardless of feature size RFS manufacture CAM grid GD modulus of elasticity E REQD concentric CONC modulus of section Z required counterbore CBORE right hand RH MEC076 Engineering Drawing Interpretation 1 Resource Package k"~J 1 MEC076 - 10 - 81 December, 1998 138 Rockwell hardness A HRA I Rockwell hardness B HRB tangent point If Rockwell hardness C HRC temperature IEMf rolled-hollow section RHS thread IHD rolled-steel angle RSA tolerance iOL rolled-sted channd RSC true position If rolled-steel jOist RSJ true profile If roughness value Ra round RD U round head RDHD undercut UCUI universal beam UB S universal column UC schedule SCHED section SECT V sheet SH vertical VERI sketch SK volume VOL spherical SfHER spigot SPI W spotface SF wrought iron WI spring steel SfRSIL square sa Y square hollow section SHS yidd point Yf stainless steel (corrosion resistance sted) CRES standard SID Standards Association of Australia SAA steel SI switch SW MEC076 Engineering Drawing Interpretation 1 Resource Package • " it:o [ MEC076 -10 - 9 [ December.