Concrete Screws
What Are Concrete Screws?
Concrete screws are self-tapping masonry fasteners that cut their own threads in a pre-drilled hole in concrete, brick, block, or mortar. They install quickly with a hammer drill and driver and are available in hex-washer and flat countersunk heads for surface-mount or flush finishes.
What Are Concrete Screws Used For?
- Anchoring sill plates, furring strips, ledgers, and bottom plates to concrete or block.
- Mounting electrical boxes, conduit straps, brackets, shelves, and clip angles.
- Light- to medium-duty fastening where a clean finish and repeatable placement are important.
- Temporary anchoring for jigs and layout (remove and relocate as needed—do not re-use the same screw).
Benefits of a Concrete Screw
- One-piece solution—no separate anchor sleeve or plug required.
- Fast installation with small hole diameters and standard drivers.
- Removable for service or relocation (use a new screw if reinstalled).
- Two common head styles: hex-washer (easy driving) and flat head (flush, countersunk look).
Concrete Screw Sizes and Types
Common diameters are 3/16″ and 1/4″. Choose length by adding fixture thickness to the required embedment in the base material. Options include:
- Blue coated (Climaseal-type): coated carbon steel for general and many outdoor applications.
- White Ruspert coated: multi-layer ceramic-type coating for enhanced corrosion protection.
- Zinc plated: economical choice for dry, interior environments.
- 410 stainless steel: best overall corrosion resistance, including coastal or chemically harsh settings.
How to Install Concrete Screws (Quick Guide)
- Select diameter and bit: typical pairings are 3/16″ screws → 5/32″ bit; 1/4″ screws → 3/16″ bit.
- Use a hammer drill: drill the hole at least 1/4″ deeper than the target embedment.
- Clean the hole: remove dust with a blower or vacuum for full holding value.
- Drive the screw: seat snugly without over-torque; avoid spinning the hole.
- Typical embedment: minimum about 1″; do not exceed manufacturer’s maximum embedment.
Always follow the specific manufacturer instructions and applicable codes.
Material & Finish Selection
- Outdoor/general: blue coated or white Ruspert coated.
- Pressure-treated lumber: use coated screws listed as compatible or 410 stainless.
- Harsh/coastal: 410 stainless.
- Dry interior: zinc plated.
Concrete Screws FAQs
See the accordion below for drill sizes, embedment rules, removability, and head-style selection.
Yes. Pre-drill with a hammer drill and a carbide-tipped masonry bit sized for the screw (3/16″ screw → 5/32″ bit; 1/4″ screw → 3/16″ bit). Clean the hole before installation.
Use 5/32″ for 3/16″ screws and 3/16″ for 1/4″ screws
Drill at least 1/4″ deeper than the intended embedment to clear dust and avoid bottoming out.
Minimum embedment is typically 1″; maximum practical embedment is about 1-3/4″ (depends on size and base material).
They can be removed, but re-using the same screw is not recommended—the threads wear and performance drops. Manufacturers caution against re-use.
No. They are self-tapping masonry screws that cut threads directly into the pre-drilled hole.
Yes, concrete, brick, block, and mortar are all acceptable base materials. Holding values vary with material quality; brick and mortar are usually weaker than sound concrete.
A hammer drill is strongly recommended to achieve the precise hole size/tolerance and best holding power.
Capacity depends on screw size, embedment, edge/spacing, and base material strength. Always use the manufacturer’s load tables; working loads are typically limited to 25% of ultimate.
Hex-washer heads drive faster and are easier to control on surface-mounted fixtures. Flat heads are used when a flush, countersunk finish is required.
Blue coated (Climaseal-type) provide extended corrosion resistance and are ACQ-compatible; white Ruspert is a multi-layer ceramic-type coating for enhanced corrosion protection; zinc plated is best for dry interior use; 410 stainless offers the highest corrosion resistance for harsh or coastal environments.
Yes, use ACQ-compatible coated carbon steel or 410 stainless concrete screws for best corrosion resistance.
Common causes include an oversize hole, dust left in the hole, insufficient embedment, or a worn bit. Drilling to the correct diameter, cleaning out dust, and using a fresh bit prevents this.
Edge distance and spacing affect capacity and vary by screw size and material. Follow the manufacturer’s edge/spacing tables or ICC-ES report for your product.
A hammer drill with the correct carbide bit, a driver or impact driver with the appropriate hex or Phillips/Star bit, and a blow-out bulb or vacuum to clear dust.