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Oven-Dry Relative Densities of Timber Species

Timber Densities

Visually Graded Lumber

Glue-Laminated Timber

Mean Oven-Dry Relative Density

D Fir-L

D Fir-L

0.49

S-P-F

–

0.42

–

S-P-F

0.44

Hem-Fir

Hem-Fir

0.46

Northern

–

0.35

S-Y-P

–

0.55

Structural Composite Lumber (SCL) Density

Parallam® (PSL)

0.50

Strength of "SWG ASSY®" Screws Made from Carbon Steel

Partial- (PT) or Full-Thread (FT)

"SWG ASSY®" Type STS

Outside Thread Diameter (mm)

Root DiameterFootnote (1) (dmin, mm)

Bending Yield StrengthFootnote (2) (MPa)

Screw Tension Strength (kN)

Unfactored Screw ShearStrengthFootnote (2) (MPa)

Unfactored Resistance

Factored ResistanceFootnote (2)

FT

VG CYL

6

3.8

969

11.3

9.04

578

PT

SK, Ecofast

6

3.9

969

11.3

9.04

578

FT

VG CYL, VG CSK

8

5

1015

18.9

15.12

641

PT

SK, Ecofast, Kombi

8

5.3

1015

18.9

15.12

641

FT

VG CYL, VG CSK

8

6.2

942

24

19.2

691

PT

SK, Ecofast, Kombi

8

6.3

942

24

19.2

691

FT

  VG CSK

12

7.1

1147

30

24

536

PT

SK, Kombi

12

7.2

1147

30

24

536

Minimum Spacing, End and Edge Distances Footnote (1) for the "SWG ASSY®" Self-Tapping Wood Screws Screw Types (d = outside diameter) Screws Loaded Laterally

Minimum Spacing  or Distance

Partial-Thread Self-Tapping

SWG ASSY® 3.0 SK, Kombi, Ecofast

Relative Density ≤ 0.42

Relative Density ≤ 0.42

Spacing parallel to grain (SP)

12d

12d

Spacing perpendicular to grain (SQ)

5d

5d

Loaded end distance (aL)

15d

15d

Unloaded end distance (a)

10d

10d

Loaded edge distance (eL)

10d

10d

Unloaded edge distance (e)

5d

5d

Minimum Spacing, End and Edge Distances Footnote (1) for the "SWG ASSY®" Self-Tapping Wood Screws Screw Types (d = outside diameter) Screws Loaded Laterally

Minimum Spacing  or Distance

Full-Thread Self-Drilling + Self-Tapping

SWG ASSY® VG plus CYL, SWG ASSY® VG plus CSK

Relative Density ≤ 0.50 kg/m3

Spacing parallel to grain (SP)

5d (7.5d in D-Fir)

Spacing perpendicular to grain (SQ)

3d

Loaded end distance (aL)

12d (18d in D-Fir)

Unloaded end distance (a)

7d (10.5d in D-Fir)

Loaded edge distance (eL)

7d

Unloaded edge distance (e)

3d

Minimum Spacing, End and Edge DistancesFootnote (1) for the "SWG ASSY®" Self-Tapping Wood Screws Screw Types (d = outside diameter) Screws Loaded Axially

Minimum Spacing  or Distance

Full-Thread Self-Drilling + Self-Tapping

SWG ASSY® VG plus CYL, SWG ASSY® VG plus CSK

Spacing parallel to grain (SP)

5d (7.5d in D-Fir)

Spacing perpendicular to grain (SQ)

2.5d

Loaded end distance (aL)

5d (7.5d in D-Fir)

Unloaded end distance (a)

–

Loaded edge distance (eL)

3d

Unloaded edge distance (e)

–
Head Pull-Through Resistance for Partial-Thread "SWG ASSY® 3.0 STS" Screws Head Pull-Through Resistance Footnote (1) Footnote (2) (kN) Partial-Thread Footnote (3) "SWG ASSY® 3.0 STS"

Diameter (mm)

Mean Oven-Dry Relative Density (kg/m3)

SK

Unfactored

Unfactored, Ø = 0.7

6

0.35

3.84

2.69

0.42

3.72

2.61

0.49

5.78

4.04

0.50

6.35

4.44

0.55

3.96

2.77

8

0.35

4.12

2.88

0.42

7.50

5.25

0.49

9.80

6.86

0.50

9.69

6.78

0.55

6.55

4.59

10

0.35

6.67

4.67

0.42

8.58

6.01

0.49

8.67

6.07

0.50

10.41

7.29

0.55

8.31

5.82

12

0.35

6.81

4.77

0.42

9.18

6.42

0.49

11.63

8.14

0.50

14.28

10.0

0.55

8.43

5.90

Head Pull-Through Resistance for Partial-Thread "SWG ASSY® 3.0 STS" Screws Head Pull-Through ResistanceFootnote (1) Footnote (2) (kN) Partial-Thread Footnote (3) "SWG ASSY® 3.0 STS"

Diameter (mm)

Mean Oven-Dry Relative Density (kg/m3)

Kombi

Unfactored

Unfactored, Ø = 0.7

6

0.35

–

–

0.42

–

–

0.49

–

–

0.50

–

–

0.55

–

–

8

0.35

1.88

1.88

0.42

2.48

2.48

0.49

3.74

3.74

0.50

4.22

4.22

0.55

3.26

3.26

10

0.35

2.60

2.60

0.42

3.78

3.78

0.49

5.23

5.23

0.50

5.08

5.08

0.55

3.86

3.86

12

0.35

3.33

3.33

0.42

4.01

4.01

0.49

5.23

5.23

0.50

6.29

6.29

0.55

5.23

5.23

Head Pull-Through Resistance for Partial-Thread "SWG ASSY® 3.0 STS" Screws Head Pull-Through ResistanceFootnote (1) Footnote (2) (kN) Partial-Thread Footnote (3) "SWG ASSY® 3.0 STS"

Diameter (mm)

Mean Oven-Dry Relative Density (kg/m3)

Ecofast

Unfactored

Unfactored, Ø = 0.7

6

0.35

1.64

1.64

0.42

1.89

1.89

0.49

3.65

3.65

0.50

3.10

3.10

0.55

2.81

2.81

8

0.35

2.14

2.14

0.42

3.07

3.07

0.49

3.85

3.85

0.50

4.80

4.80

0.55

4.76

4.76

10

0.35

2.70

2.70

0.42

3.87

3.87

0.49

6.61

6.61

0.50

5.69

5.69

0.55

4.43

4.43

12

0.35

–

–

0.42

–

–

0.49

–

–

0.50

–

–

0.55

–

–