STS Industrial - Bolts & Screws




Code Listed for Cracked Concrete

The Strong-Bolt® from Simpson Strong-Tie is a wedge anchor specifically designed for optimum performance in both cracked and uncracked concrete; a requirement that the 2009 IBC places on post-installed anchors. Rigorously tested according to the latest industry-wide criteria, the Strong-Bolt anchor is proven to offer increased reliability in the most adverse conditions, including performance in cracked concrete under static and seismic loading. The proprietary tri-segmented clip has dual undercutting embossments on each segment which enable secondary or “follow-up” expansion if a crack forms and intersects the anchor location. This significantly increases the ability of the Strong-Bolt wedge anchor to carry load if the hole opened slightly due to a crack. The Strong-Bolt anchor sets like a standard wedge anchor and is available in Imperial fractional sizes.

  • Tri-segmented clip: Each segment is able to adjust independently increasing follow-up expansion should the hole increase in size as a result of a crack.
  • Dual embossments on each clip segment: Allows the clip to undercut into the concrete increasing follow-up expansion should a crack occur.
  • 316 stainless steel clip: In addition to superior corrosion resistance, a stainless steel clip offers better “memory”. This memory contributes to the anchor’s performance should the hole size increase due to a crack.
  • Imperial fractional sized anchor: Fits most fixtures and installs with common drill bits sizes and tools. No need to buy additional tools to install a metric anchor and no special couplers needed.
  • Installs like a standard wedge anchor: No complicated installation procedure. No need for special bits or installation tools.
  • The head is stamped with the Simpson Strong-Tie® “≠” sign and size ID for easy post installation identification.
  • Zinc Plated Carbon Steel with 316 Stainless Steel Clip.

Strong Bolt Installation

Strong Bolt Clip


    strong bolt product data

    1. The published length is the overall length of the anchor.
    2. Allow one anchor diameter for the nut and washer thickness plus the fixture thickness when selecting a length.

    Length Identification Head Marks on Strong Bolt Anchors

    (corresponds to length of anchor – inches).

    Strong Bolt Length Identification Head Marking


    Strong Bolt material specifications

    1. Zinc meets ASTM B 633, Class SC 1 (Fe / Zn 5), Type III

    Application: Interior environment where low levels of moisture and corrosive chemicals are present.


    • Holes in metal fixtures to be mounted should exceed nominal anchor diameter by 1/16″ for 1/4″ through 5/8″ diameter anchors, and by 1/8″ for all other diameters.
    • Do not use an impact wrench to set or tighten the Strong-Bolt Anchor.

    Caution: Oversized holes in the base material will make it difficult to set the anchor and will reduce the anchor’s load capacity.

    Strong-Bolt Anchor Installation Data

    Strong Bolt Installation Data

    Strong-Bolt Anchor Installation Sequence

    Strong Bolt Installation Sequence

    • Drill a hole in the base material using a carbide drill bit the same diameter as the nominal diameter of the anchor to be installed. Drill the hole to the specified embedment depth and blow it clean using compressed air. Overhead installations need not be blown clean. Alternatively, drill the hole deep enough to accommodate embedment depth and dust from drilling.
    • Assemble the anchor with nut and washer so the top of the nut is flush with the top of the anchor. Place the anchor in the fixture and drive into the hole until washer and nut are tight against fixture.
    • Tighten to the required installation torque.

    Strong-Bolt® Anchor Installation Information and Additional Data¹

    Strong Bolt Installation Information and Additional Data

    1. The information presented in this table is to be used in conjunction with the design criteria of ACI 318 Appendix D.

    The load tables list values based upon results from the most recent testing and may not reflect those in current code reports. Where code jurisdictions apply, consult the current reports for applicable load values.


    The Strong-Bolt wedge anchor has been tested in accordance with the ICC-ES’s Acceptance Criteria for Mechanical Anchors in Concrete Elements (AC193) and ACI 355.2 for the following:

    • Static tension and shear loading in cracked and uncracked concrete
    • Seismic and wind loading in cracked and uncracked concrete
    • Performance in cracked concrete

    Vibratory Load Testing: A 150 lb. concrete block was suspended from a 1/2 ” diameter anchor embedded at 2 1/4″ and vibrated for 12.6 million cycles at a frequency of 30 Hz and an amplitude of 0.025 inches. Subsequent load test showed no reduction in ultimate tension capacity.

Sources: ASTM Standards for Mechanical Fasteners and Related Processes 2nd Edition, Inch Fastener Standards 8th Edition, Simpson Strong-Tie Anchoring and Fastening Systems for Concrete and Masonry,

Note: All material included on this page is informational only, and should not be used as one’s sole source for design purposes. STS Industrial, Inc. and its affiliates do not guarantee the accuracy of the information on this site, and retain no liability for the use or misuse of the information contained on this site.