Concrete Wedge Anchor

Purchase Concrete Wedge Anchors

Wedge Anchor Installation Video

Technical Information:

The ThunderStud® wedge anchor consists of two pieces permanently preassembled into a single unit. The carbon steel rod is threaded for a portion of its length. The extreme end of the threaded portion is rounded to protect the threads from damage while the anchor is being driven into the hole drilled in the concrete. The other end of the rod has a necked down diameter, which runs for a short distance, at the end of which it tapers outwardly to the full diameter of the rod. A precision formed universal clip made of carbon steel is permanently assembled around the necked down diameter to complete the anchor. Each package contains the correct number of nuts and washers.

Concrete Wedge Anchor - Approvals:

  • Listed by Underwriters Laboratories (UL) Listed, EX2224(N)
  • NY Board of Standards and Appeals
  • Meets or exceeds U.S. Government G.S.A. Specifications FF-S-325 Group 11, Type 4, Class 1

Concrete Wedge Anchor - Applications:

Light to heavy-duty into solid concrete.

Concrete Wedge Anchor - Installation:

  1. Drill a hole in the concrete using a hammer drill and a carbide tipped masonry drill bit conforming to ANSI B94, 12-77, the same diameter as the ThunderStud® wedge anchor. If the fixture being fastened is in place and being used as a template to locate the hole for the ThunderStud® anchor, the mounting hole in the fixture should afford clearance for the universal wedge clip on the stud.
  2. Clear the hole of all debris, then place the ThunderStud® wedge anchor through the hole in the fixture or directly into the concrete, and hammer it in to the drilled hole, ensuring that they are installed to the desired depth.
  3. Turn the nut by hand until the unit is "snugged up". Tighten the nut with a torque wrench to ensure they are tightened to the required torque value.

Concrete Wedge Anchor - Anchor Length:

To determine minimum anchor length required, simply add minimum embedment, plus fixture thickness, plus the thickness of the nut and washer. The ThunderStud® wedge anchor requires no maximum hole depth. The depth of the hole in the concrete should be the length of the wedge anchor minus the thickness of the material being fastened. This will result in some extra depth to accommodate a minor amount of concrete cuttings which may not be able to be cleaned out of the hole.

Concrete Wedge Anchor - Anchor Spacing:

The forces on a ThunderStud® wedge anchor are transferred to the material in which it is installed. If the anchors are installed too close together, it can cause an interaction of the forces, thus reducing the holding power of the anchors. As a rule of thumb, the concrete anchor industry has established a minimum standard of ten (10) anchor diameters for spacing between anchors and five (5) anchor diameters from an unsupported edge. When vibration or sudden impact are part of the load condition anchor spacing should be increased.

Concrete Wedge Anchor - Material Composition:

MATERIAL STEEL STAINLESS SPECIFICATION STEEL STAINLESS
Stud AISI C12L14 303, 304, 316 ASTM A108, A510 A276, A479
Clip AISI C1010-1018
1037 		304 316 FEDERAL FF-SS325, GROUP II
TYPE 4, CLASS 1 		A581, A582
FF-S-325
Washer AISI C1010-1018 TYPE 18-8 316 PLATING ZINC QQ-Z-325C GROUP II
Nut LOW CARBON STEEL
ASTM A 563, GRADE A 		304, 316 GALVANIZED TYPE II CLASS 3 ASTM A 153 CLASS C TYPE 4 CLASS 1 PASSIVATED

Concrete Wedge Anchor - Technical Data:

Anchor Diameter (in.) Embed. Depth (in.) Torque Ft/Lb 2000 PSI 4000 PSI 6000 PSI
Tension (LB) Shear (LB) Tension (LB) Shear (LB) Tension (LB) Shear (LB)
1/4 1-1/8 5-10 1170 1443 1771 1813 2773 2635
1-3/4 1841 1443 2408 1813 2773 2635
2-3/4 1975 1443 2748 1813 2830 2635
3/8 1-1/2 25-30 1631 4318 3636 5121 4448 6232
3 3229 4318 5653 5121 5975 6232
5 4074 4318 6328 5121 6360 6232
1/2 2-1/4 50-60 3999 7419 6714 9377 9616 9888
4 6336 7419 8942 9377 10192 9888
6 6902 7419 10175 9377 12064 9888
5/8 3-3/4 75-90 4999 8264 8747 12928 9760 16373
5 8854 8264 15590 12928 16802 16373
7 9381 8264 16710 12928 17732 16373
3/4 3-1/4 150-175 6638 12504 11314 17050 16230 22965
6 10084 12504 18408 17050 21092 22965
8 11170 12504 19805 17050 22522 22965
7/8 3-7/8 200-250 8392 18250 16354 20234 16801 23980
5-3/4 12064 18250 18250 20234 23404 23980
8-3/4 12784 18250 16850 20234 25575 23980
1 4-1/2 250-300 9773 23617 18250 27605 27460 28909
7-1/2 11890 23617 26726 27605 34960 28909
10 15590 23617 30491 27605 37840 28909
1-1/4 5-1/2 400-450 17550 32275 22971 42690 32368 55566
7 21050 32275 27845 42690 48366 55566
10 27893 32275 34788 42690 61272 55566

Anchor Size Hole Size Min. Embedment Std. Thread Length
1/4”  all sizes 1/4” 1-1/8” 3/4”
3/8” x 2-1/4” 3/8” 1-1/2” 7/8”
3/8” 3/8” 1-1/2” 1-1/8”
1/2” all sizes 1/2” 2-1/4” 1-1/4”
5/8”  all sizes 5/8” 2-3/4” 2”
3/4”  all sizes 3/4” 3-1/4” 2”
7/8” 7/8” 3-7/8” 2-1/4”
1” 1” 4-1/2” 2-1/4”
1-1/4” 1-1/4” 5-1/2” 3-1/4”

Values shown are average ultimate values and are offered only as a guide and are not guaranteed. A safety factor of 4:1 or 25% is generally accepted as a safe working load. Reference should be made to applicable codes for the specific working ratio. *Tested by ATEC in accordance with ASTM E488-90 and ICBO ES AC01. Minimum embedment for satisfactory anchor performance is 4-1/2 bolt diameters. Deeper embedments may yield higher tension and shear capacities.