Fractional Equivalents For Decimal Values

Fractional Equivalents For Decimal Values 205

Where rafter lengths are determined by multiplying unit lengths by the run, the answer will almost invariably result in a decimal. Such decimal values may be readily translated into fractional forms by means of the accompanying table.

Example: A roof of ⅓ pitch has a common rafter run of 14'; find the length of common rafter.

Answer: 14x14.42"=201.88" or 16.82'. By the table, .82 = 53/64. A carpenter, however, would not care for such accuracy; the nearest 1/16" or even ⅓" would be sufficient.

Wood And Machine Screw Sizes

The difference between consecutive sizes is .01316".

Wood And Machine Screw Sizes 206

Frequently the carpenter wishes to know the diameter of hole necessary to receive the shank of a screw of a certain gage. Should a screw gage be accessible, he may readily determine this. Should no gage be at hand, he may determine the size of hole by consult-ing the accompanying table of Wood and Machine Screw Sizes..

Example: What size bit must be selected to bore a hole for a No. 10 screw. By the table, a No. 10 screw is .18944" in diameter. By the table of Fractional Equivalents for Decimal Values it will be seen that a 3/16" bit must be used. The test for gage of screw is always made over the shank just below the head.

Length And Number Of Wire Nails To The Pound

Length And Number Of Wire Nails To The Pound 207

Nails are sold in quantity by the keg, 100 lbs. of nails, exclusive of the keg. Twenty, 30,40,50 and 60d are" base." Other sizes have certain fixed additions per keg to this base price. For example, the price list adopted by manufacturers in 1896 allows an addition per keg of $.70 for 2d common, $.45 for 3d common, etc.

Wire nails are also bought and sold by weight, the size of wire according to the standard wire gage and the length in inches being taken into consideration in specifying the size and in fixing the price per pound.

Common wire nails are thick and have large flat heads. They are used in rough work where strength is desired. Finishing nails are used for fine work such as inside woodwork and cabinet work. Casing nails are somewhat thicker and stronger than finishing nails; they have smaller heads.

Wire Brads

Size, inches..................

1

Wire Gage, nos...............

20

18

19

19

18

16

18

17

18

Approx. no. brads to lb........

7500

7200

4267

3556

2758

2600

2364

1781

2069

Size, inches..................

1

1

1

1

1

1

1

1

1

Wire Gage, nos...............

17

16

17

16

16

15

14

15

14

Approx. no. brads to lb.......

1558

1143

1246

913

761

584

500

500

406

Size, inches..................

2

2

2

2

3

3

3

...

...

Wire Gage, nos...............

14

13

13

12

14

12

11

...

...

Approx. no. brads to lb.......

350

268

214

164

150

137

105

...

...

Board Measure Table

Board Measure Table

Strength Of Materials Yellow Pine Posts

Load in Tons

Length

IN FT.

Size in inches

4x4

5x5

6x6

7x7

8x8

9x9

8

4

5

6

7

8

9

10

3

4

5

6

7

8

12

2

3

4

5

6

7

14.........................

1

2

3

4

5

6

16.........................

...

1

2

3

4

5

18.........................

1

2

3

4

Hard Pine Beams And Girders

Load in Tons

Length

IN FT.

Size in inches

2x6

3x6

4x6

6x6

8x8

6................................

1

1

2

3

5

8.................................

1

1

2

5

10................................

1

2

4

12................................

1

1

3

14................................

. .

1

2

16................................

• • a

2

18................................

1

STEEL I BEAMS

Load in Tons

Length in ft.

Size in inches

6

8

12

10....

7

14

18

12....

6

12

16

14....

5

10

14

16....

4

8

12

18....

2

6

10

20....

4

8

22....

2

6

24....

..

4

BRICK PIERS

Load in Tons

Height

IN FT.

Size in inches

6x6

6x8

8x8

8x12

12x12

12x16

16x16

6.........................

2

3

4

5

6

7

9

8.........................

1

2

3

4

5

6

8

10.........................

1

2

3

5

5

6

7

Stresses For Structural Timbers

Working Unit Stresses Used In Dry Locations

Bending

Compression

Species of Timber

Stress in extreme fibre

Lbs. sq. in.

Horizontal shear stress

Lbs. sq. in.

Parallel to grain "Short

Columns" Lbs. sq. in.

Perpendicular to grain Lbs. sq. in.

*Fir, Douglas -

Dense grade............

1,600

100

1,200

350

Sound grade.........

1,300

85

900

300

Hemlock, eastern.........

1,000

70

700

300

Hemlock, western...........

1,300

75

900

300

Oak.......................

1,400

125

900

400

Pine, eastern white..........

900

80

700

250

Pine, Norway...............

1,100

85

800

300

*Pine, southern yellow Dense grade..............

1,600

125

1,209

350

Sound grade.........

1,300

85

900

300

Spruce.....................

900

70

600

200

Tamarack..............

1,200

95

900

350

* Note: The safe working stresses given in this table are for timbers with defects limited according to the sections on defects in the rules of the Southern Pine Association for Select Structural Material. "Dense" southern yellow pine and "dense" Douglas fir should also conform to the other requirements of this rule. "Sound" southern yellow pine and "sound" Douglas fir require no additional qualifications, whereas the other species should, in addition to being graded for defects, have all pieces of exceptionally low density for the species excluded. •

This table gives working unit stresses for structural timbers used in dry locations, and is compiled in the main from material furnished by the Forest Products Laboratory, Madison, Wis.

Table Of Brick Wall Contents In Number Of Bricks

Seven Bricks to Each Sq. Ft. of Wall Surface

No. OF

SQ FT. OF WALL

Thickness

4"

8"

12'

16"

20"

24"

1....................

7

15

23

30

38

45

2....................

15

30

45

60

75

90

3....................

23

45

68

90

113

135

4....................

30

60

90

120

150

180

5....................

38

75

113

150

188

225

6....................

45

90

135

180

225

270

7....................

53

105

158

210

263

315

8....................

60

120

180

240

300

360

9....................

68

135

203

270

338

405

10....................

75

150

225

300

375

450

20....................

150

300

450

600

750

900

30....................

225

450

675

900

1,125

1,350

40....................

300

600

900

1,200

1,500

1,800

50....................

375

750

1,125

1,500

1,875

2,250

60....................

450

900

1,350

1,800

2,250

2,700

70....................

525

1,050

1,575

2,100

2,625

3,150

80....................

600

1,200

1,800

2,400

3,000

3,600

90....................

675

1,350

2,025

2,700

3,375

4,050

100....................

750

1,500

2,250

3,000

3,750

4,500

Example - Determine the number of bricks in a wall 12"X18'X60'. Solution - The wall contains a surface area of 1,080 sq. ft. By the table

100 sq. ft. contains 2,250 bricks, then 1,000 sq. ft. will contain 22,500 bricks.

80 sq. ft. will contain, by the table, 1,800 bricks, making a total of 24,300 bricks.