CEMP-E
TI 809-07
NOVEMBER 1998
5. FASTENERS AND CONNECTIONS
a. Sheet Metal Screws. AISI Specification for the Design of Cold-Formed Steel Structural
Members and accompanying Commentary - Section E4. This section is applicable to screws with
a nominal diameter of 2.03 mm (0.08 in) d 6.35 mm (0.25 in). The nominal diameter is
measured across the threads and will be thread forming or thread cutting. Screws may be used
with or without a self drilling point. Table 2-4 gives some suggested loading values for screw
connections. Pullout values are for attaching facing materials and are not to be used for
connection design.
b Bolts. AISI Specification for the Design of Cold-Formed Steel Structural Members
and accompanying Commentary - Section E3. Bolts are designed for sheets with the thinnest
sheet being less than 4.8 mm (3/16 in). When the thinnest sheet is greater than 4.8 mm (3/16 in)
use the AISC specification. Four design conditions need to be considered:
Longitudinal shearing of the sheet parallel to the through the end of the sheet,
Bearing or piling up behind the bolt,
Tearing through the net section,
Shearing of the bolt.
Table 2-4: Suggested Capacities for Screw Connectors in kN (lbs)
Steel
No. -14
No. 12-14
No. 10-14
No. 8-14
No. 6
Nominal /
Design
Shear or
Pullout
Shear or
Pullout
Shear or
Pullout
Shear or
Pullout
Shear or
Pullout
Thickness
Bearing
Bearing
Bearing
Bearing
Bearing
mm (in)
2.583
2.60
1.57
2.00
1.44
1.45
1.40
NA
1.35
NA
NA
(0.1017)
(585)
(352)
(450)
(324)
(327)
(314)
(303)
1.811
2.27
1.08
1.83
0.96
1.27
0.91
NA
0.89
NA
NA
(0.0713)
(511)
(242)
(412)
(215)
(286)
(205)
(200)
1.438
1.89
0.71
1.68
0.68
1.16
0.67
1.05
0.63
NA
0.59
(0.0566)
(426)
(159)
(377)
(153)
(261)
(151)
(236)
(142)
(132)
1.146
1.34
0.45
1.23
0.45
1.17
0.44
1.10
0.42
0.84
0.37
(0.0451)
(301)
(101)
(276)
(101)
(263)
(98)
(248)
(94)
(188)
(83)
0.879
0.69
0.32
0.64
0.31
0.63
0.31
0.62
0.30
0.59
0.24
(0.0346)
(154)
(71)
(143)
(70)
(141)
(69)
(140)
(68)
(133)
(53)
Notes:
1. NA: not applicable, two thicknesses of this metal gage cannot be connected by this size screw.
2. Screw capacity is based on a minimum connected strength of F = 228 MPa (33 ksi). The ratio of the material ultimate tensile
y
strength to yield strength should be equal to or greater than 1.15.
3. Screw a spacing and edge distance shall not be less than 1.5D or P/0.6F , where D is the screw shank diameter and P is the
yt
shear load.
4. Screw capacities are based on average test results divided by a safety factor of 3.0. Test data is available from Buildex Division
of ITW, Inc Itasca, Illinios; test #845, uninspected values.
5. For steels having yields other than 228 MPa (33 ksi), use the following formula:
Table Value(Actual yield strength)/(228 or 33 in consistent units) = New value
c. Welds. AISI Specification for the Design of Cold-Formed Steel Structural Members and
accompanying Commentary - Section E2. The maximum thickness for the use of the AISI
specification when welding sheets together is 4.6 mm (0.18 in) for the thinnest sheet. When
welding thicker sheets use the AISC specification. Resistant welded sheets are limited to 3.2 mm
(0.125 in) or less for the thinnest sheet. Table 2-5 gives some suggested values for fillet and
flare-groove welds.
2-12
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