Computer Aided Design (CAD) Engineering Drawing Standards - BS308.
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Transcript of Computer Aided Design (CAD) Engineering Drawing Standards - BS308.
SOME TECHNICAL TERMS (page 1)
Flange
Keyway
Keyway
Key
Taper
Shaft
Shoulder
Bush
Web
Bore
Boss
Collar
Spoke
Rim
Hub
Pulley
Rib Bracket
base
Fillet
Table
Slot
Spotface Counterbore
Lug Countersink
Dowel Blind hole
Tee slot
Chamfer
Spigot Recess
SOME TECHNICAL TERMS (page 1)
CAN YOU DETERMINE THE PROJECTION SYSTEM USED? (first or third angle?)
CAN YOU IDENTIFY THE TYPES OF HOLES ABOVE?
COMMON LINE TYPES (page 5)
1. Continuous Thick (0.5mm) TYPE A
2. Continuous Thin (0.25mm) TYPE B
3. Dashed Thin (0.25mm) TYPE E
4. Chain Thin (0.25mm) TYPE F
Leader Lines To show where dimensions or notes
apply. Always end in arrowheads or dots.
Arrowheads touch and stop on a line Dots should be within the outline of the
object. Long or intersecting leader lines
should not be used.
General Points on Drafting Arrows:
Triangular and Solid Length = 3 x width Arrows on Dimensions -> 3-5mm Long Arrows showing direction of view -> 7-
10mm Long Text Height = Not less than 3mm. Underlining of text is not recommended. Notes of a general character to be
grouped together.
Commonly Accepted Symbols and Abbreviations AF ASSY CRS CL CHAM CH HD CSK CSK HD
CBORE CYL DIA DRG EQUI SP EXT FIG. HEX
HYD INSUL INT LH LG MATL MAX MIN
Commonly Accepted Symbols and Abbreviations NO. O/D PATT NO. PCD RAD R REQD RH
RD HD SCR SH SK SPEC SR SFACE SQ
STD THD TYP UCUT VOL WT
SECTIONS AND SECTIONAL VIEWS
(page 12 BS308)
Hatching is Drawn with Type B (Continuous Thin) Lines, equally spaced at 45º.
Preferably not less than 4mm Apart With very small parts, never less than
1mm On adjacent parts, alternate the
direction of Hatching. Correct Section Line – Type F (Chain
Thin)
SECTIONS AND SECTIONAL VIEWS(page 15 BS308)
PARTS NOT NORMALLY SECTIONED WHEN THE CUTTING PLANE PASSES LONGITUDINALLY THROUGH: FASTNERS (bolts, nuts) SHAFTS,
RIBS, WEBS, SPOKES of WHEELS etc.