Page 133 - Estimators Piping Man Hour Manual

116 Section Two-FIELD FABRICATION

DRILLING HOLES IN WELDED ATTACHMENTS

Carbon Steel Material

NET MAN HOURS EACH
Thickness of HOLE SIZE
Plates, Angles,
Etc. in Inches 3/4 "and smaller 7/8", 1" and 1-1/8" 1-1/4", 1-1/2" and 2" 2-1/4" and 2- 1/2"
1/2 "or less 0.24 0.29 0.34 0.47
3/4 0.29 0.34 0,43 0.64
1 0.31 0.40 0.49 0.67
1-1/4 0.40 0.49 0.55 0.71
1-1/2 0.49 0.55 0.71 0.91
1-3/4 0.55 0.71 0.86 1.12

2 0.71 0.82 1.00 1.32
2-1/2 0.82 0.91 1.12 1.62
3 0.91 1.12 1.32 1.82
3-1/2 1.01 1.21 1.52 2.14
4 1.21 1.42 1.73 2.44

Unlisted thickness of plate or size of holes take the next higher listing.
If holes are to be tapped—Add 33-1/3%.
Drilling of sentinel safety or tell tale holes should be charged at .05 man hours each net.

The above man hours are for drilling holes in flat carbon steel plate and structural shapes only.
For drilling holes in pipe or other contoured objects, perpendicular to contoured surface, add 100% to above man
hours.
For drilling holes in pipe or other contoured objects, oblique to contoured surface, add 175% to above man hours.