WL 141 Unit 15

WL 141

1. Blueprint Reading for
Welders
8th Edition
Unit 15
Plug and Slot Welds

2. Objectives
•Define the following terms:
–Depth of filling
–Spacing of plug
–Number of welds
•Define the contour and finish of a
plug weld
•Define the contour and finish of a
slot weld

3. Objectives (cont’d.)
•Distinguish a plug weld from a slot
weld on a drawing
•Interpret the dimension applied to
the plug and slot weld symbols

4. Plug and Slot Welds
•Shape of hole differentiates plug
and slot welds
–Plug weld: round hole
–Slot weld: elongated hole
•Plug weld symbol designates a fillet
weld in a round or slotted hole
•Identified by same symbol
–Plug weld symbol has diameter
symbol on left side

5. Plug and Slot Welds
(cont’d.)
•Slot weld identified by reference to
detail drawing in tail
–Detail drawing shows shape, location,
orientation of slot weld
•Symbol located below reference
line: hole is in arrow side
•Symbol above reference line: hole
in other side

10. Dimensions Applied to the
Plug and Slot Weld
Symbol
•Dimensions applied to plug welds:
–Size, depth of filling, included angle of
countersink, number of welds, pitch
•Size refers to diameter (inches) at
base of weld
–Located to left of weld symbol
–Preceded by diameter symbol

12. Dimensions Applied to the
Plug and Slot Weld
Symbol (cont’d.)
•Width dimension of slotweld
located to left of symbol
–Represents width of minor axis of slot
at its base
•Sides straight or tapered
–Included angle on same side of
symbol

15. Dimensions Applied to the
Plug and Slot Weld
Symbol (cont’d.)
•Numberof welds shown in
parenthesis below an arrow side
–May be specified in tail
•Included angle placed below angle
dimension
–Shown above the symbol when
symbol has an other side significance

17. Dimensions Applied to the
Plug and Slot Weld
Symbol (cont’d.)
•Spacing(pitch) specified to right
of plug weld symbol
–Slot welds: pitch dimension follows
length dimension
–Preceded by hyphen
–May be shown in detail drawing

20. Dimensions Applied to the
Plug and Slot Weld
Symbol (cont’d.)
•Depth of fillingshown within the
symbol for both welds
–When not shown complete filling
required
•Dimensions located on same side
of reference line as the symbols

24. Contour and Finishing
•Plug and slot welds finished with
flush or convex contour
•Contour symbol shown above or
below the weld symbol
–Depends on arrow side or other side
significance
•Postweld finish specified above or
below the contour symbol
–Flat finish specified in note in the tail

26. Plug Welds with Three or
More Joints
•Two or more members welded to
another by means of plug weld
•Joints to be welded shown by
section drawing
•Section drawing shows members
that require joint preparation

28. Summary
•Shape of hole differentiates plug
and slot welds
•Dimensions applied to plug weld:
–Size
–Depth of filling
–Included angle of countersink
–Number of welds
–Spacing (pitch)

29. Summary (cont’d.)
•Plug and slot welds finished with
flush or convex contour
•Flat finish specified by a note in the
tail
–Note for flush finish not needed
•When two or more members
welded to another:
–Joints shown in section drawing