HDC Concentric Holdown

The unique design of the HDC holdowns eliminate eccentricity. They install with SDS screws (included) to reduce slip and provide a greater net section area of the post compared to bolts.

Material: 10 gauge strap.

Finish: Galvanized strap, aluminum base.

Installation:

Use all specified fasteners. See General Notes.
Install on concrete.
Sized for 2-2x, and 4x. Center 2-2x posts on holdown.
Install Simpson's SDS 1/4"x2 1/2" wood screws, which are provided with the holdown. (Lag screws will not achieve the same load.)
Slot in the seat allows for 3/8" of adjustment perpendicular to plate. (Standard N series cut washer required, 1 3/4" diameter - 0.134" thick.)
Witness slot in the base to inspect the nut.
Maximum anchor bolt height above concrete is 2 1/2".
To tie multiple 2x members together, the Designer must determine the fasteners required to join members to act as one unit without splitting the wood. See SDS Screw information.
Aluminum standoff cannot be in contact with pressure-treated wood.
SDS screws install best with a low speed high torque drill with a 3/8" hex head driver
Refer to technical bulletin T-ANCHORSPEC for post-installed anchorage solutions.

For holdowns, per ASTM test standards, anchor bolt nuts should be finger-tight plus 1/3 to 1/2 turn with a hand wrench, with consideration given to possible future wood shrinkage. Care shold be taken not to over-torque the nut. Impact wrenches should not be used.

The Designer must specify anchor bolt type, length and embedment. See SB and SSTB Anchor Bolts.
Loads are based on static tests on wood studs, limited by the lowest of 0.125" deflection, test ultimate divided by 3, or the wood screw value.
Deflection at Highest Allowable Tension Load includes fastener slip, holdown elongation, and anchor bolt elongation (L = 5").
The HDC's will be limited by wood compression capacity if installed on a sill plate. HDC5/22 and HDC10/22 will achieve an allowable load of 4005 lb. on a DFL plate. HDC5/4 and HDC10/4 will achieve an allowable load of 4940 lb. on a DFL plate, which does not take deflection into account. Full tension values apply when installed on a sill; deflection may be higher.
Higher values may be obtained when HDC is not placed at an edge or with f'_c concrete strength > 2500 psi.
Structural composite lumber columns have sides that show either the wide face or the edges of the lumber strands/veneers. Values in the tables reflect installation into the wide face.
Post design shall be by Designer.

					Legacy Reports
	IAPMO ES ER	ICC-ES ESR	CITY OF LOS ANGELES	STATE OF FLORIDA	ICC-ES NER	ICC-ES ER	ICC-ES ES
HDC	See specific model numbers for code listings.
HDC10	No code listing. Please contact us for test data.
HDC10/22	No code listing. Please contact us for test data.
HDC10/22-SDS2.5			RR25540	FL1463		ER-5938
HDC10/4	No code listing. Please contact us for test data.
HDC10/4-SDS2.5			RR25540	FL1463		ER-5938
HDC5	No code listing. Please contact us for test data.
HDC5/22	No code listing. Please contact us for test data.
HDC5/22-SDS2.5			RR25540	FL1463		ER-5938
HDC5/4	No code listing. Please contact us for test data.
HDC5/4-SDS2.5			RR25540	FL1463		ER-5938