FAQ

ESR-4948
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Most Widely Accepted and Trusted Page 2 of 8
maximum value). The thickness of the wood main member
must be equal to or greater than the screw length less the
thickness of the side member.
4.0 DESIGN AND INSTALLATION
4.1 Design:
The design values in this report are intended to aid the
designer in meeting the requirements of IBC Section
1604.2. For connections not completely described in this
report, determination of the suitability of the Hillman
TM
Structural Screws for the specific application is the
responsibility of the designer and is outside the scope of this
report. The designer is responsible for determining the
available strengths for the connection, considering all
applicable limit states, and for considering serviceability
issues.
4.1.1 Screw Strength: Allowable screw tension strengths
(ASD), and design screw tension strengths (LRFD) and
minimum specified bending yield strength for the screws are
shown in Table 2.
4.1.2 Reference Withdrawal and Pull-through Design
Values: Reference withdrawal (W) design values in pounds
per inch of thread penetration, for screws installed
perpendicular to the face of the wood member are shown in
Table 3, and reference head pull-through values (W
H
) are
shown in Table 4.
4.1.3 Lateral Connections in Accordance with the NDS:
The reference lateral design strength for connections of two
or more wood members using the Hillman
TM
Large Hex
Washer Head Screws and Wafer Head Screws may be
designed in accordance with the NDS, subject to the
following conditions:
1. The applicable specified bending yield strength from
Table 2 must be used for design.
2. The minor thread diameter, D
r
, must be used where
‘D’ is referenced in Tables 12.3.1A, 12.3.1B and
12.3.3 of the NDS (Tables 11.3.1A, 11.3.1B and
11.3.3 of the 2012 NDS for the 2012 IBC).
3. Applicable for designs where any Yield Mode (I
m
, I
s
,
II, III
m
, III
s
or IV) governs the calculation.
4. Wood species combinations must have assigned
specific gravity between 0.42 and 0.50.
5. Wood side member thickness must be a minimum of
1.5 inches (38.1 mm).
6. Screw penetration into the main member must be a
minimum of 2.5 inches (63.5 mm).
7. Dowel bearing length shall be determined in
accordance with Section 12.3.5.3 of the NDS
(Section 11.3.5.2 of the 2012 NDS for the 2012 IBC),
using 2*D
r
as the tapered tip length, E.
8. Spacing, edge and end distance must be in
accordance with Table 6, and as needed to prevent
splitting of the wood.
4.1.4 Two-member Lateral Wood-to-wood
Connections Based on Testing: For select connection
configurations, testing has been conducted to determine
reference lateral design values which exceed those
determined in accordance with the NDS. Reference lateral
design values based on testing are shown in Table 5.
4.1.5 Adjustments to Reference Design Values: The
reference design values must be adjusted in accordance
with the requirements for dowel-type fasteners in Section
11.3 of the NDS (Section 10.3 of the NDS for the 2012 IBC),
to determine allowable loads for use with ASD and/or design
loads for use with LRFD. The reference design values must
also be adjusted in accordance with Section 12.5 of the NDS
(Section 11.5 of the NDS for the 2012 IBC), as applicable.
When the capacity of a connection is controlled by the screw
strength, the allowable connection strength must not be
increased by the adjustment factors specified in the NDS.
4.1.6 Governing Design Values: T
he allowable load for a
two-member, single-screw connection in which the screw is
subject to tension is the least of: (a) the reference
withdrawal design load value given in Table 3, multiplied by
the embedded thread length, and adjusted by all applicable
adjustment factors; (b) the reference head pull-through
design value given in Table 4, adjusted by all applicable
factors; and (c) the allowable screw tension strength given
in the Table 2.
4.1.7 Connections with Multiple Screws: Connections
made with multiple screws must be designed in accordance
with Sections 11.2.2 and 12.6 of the NDS (Sections 10.2.2
and 11.6 of the NDS for the 2012 IBC).
4.1.8 Combined Loading: Where the screws are
subjected to combined lateral and withdrawal loads,
connections shall be designed in accordance with Section
12.4.1 of the NDS (Section 11.4.1 of the NDS for the 2012
IBC).
4.1.9 Capacity Requirements for Wood Members:
When designing a connection, the structural members must
be checked for load-carrying capacity in accordance with
Section 11.1.2 of the NDS (Section 10.1.2 of the NDS for
the 2012 IBC), and local stresses within multiple-fastener
connections must be checked against Appendix E of the
NDS to ensure the capacity of the connection and fastener
group.
4.2 Installation:
Hillman
TM
Structural Screws must be installed in
accordance with the report holder’s published installation
instructions and this report. The screws must be installed
perpendicular to the face of the wood member. Screws must
be installed with the minimum spacing, end distances, and
edge distances needed to prevent splitting of the wood or
as noted in Table 6, whichever is more restrictive. The
underside of the flat portion of the large hex washer head
screw head must bear against the surface of the wood side
member or steel plate. Wafer head screws must be driven
flush with the surface of the wood. Screws must not be
overdriven. Installation must be performed without
predrilling. The screws must be installed by turning with a
power driver, not by driving with a hammer.
5.0 CONDITIONS OF USE
The Hillman
TM
Structural Screws described in this report
comply with, or are suitable alternatives to what is specified
in, those codes listed in Section 1.0 of this report, subject to
the following conditions:
5.1 The screws must be installed in accordance with the
report holder’s published installation instructions and
this report. In the case of a conflict between this report
and the report holder’s instructions, this report
governs.
5.2 Design loads for the screws must not exceed the
available strengths described in Section 4.1.
5.3 Calculations and details demonstrating compliance
with this report must be submitted to the code official.
The calculations and details must be prepared by a
registered design professional where required by the
statutes of the jurisdiction in which the project is to be
constructed.
5.4 The screws have only been evaluated for use in dry
service applications. Use in wet service conditions is
outside the scope of this report.