Concrete & Masonry

Fasteners for conduit straps on masonry

Lay out a straight conduit run and choose the strap and anchor combination specified for the route, fixture and wall.

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Plan the supports before drilling

Conduit straps and electrical box mounting

Check the support requirements for the exact conduit and fittings. Concrete, solid masonry and hollow block can require different anchors. Box mounting has its own support detail.

Confirm the complete fixing

Have qualified personnel confirm the route, support schedule and permitted fastener. Check the strap hole, wall substrate, anchor diameter and drive together.

Find the right fastener

Compare fasteners by material and connection before you choose a size.

Open the fastener calculator

Tools & accessories

Choose the tools that match your materials and fastening system.

8 mm Magnetic Nut Setter

Use only where the selected fastener head measures 8 mm across flats.

View accessory

Mini Magnetic Level

Check short sections and fittings for level.

View accessory

Attach conduit straps to concrete or masonry

Gather the matched parts and tools

Check strap size, specified anchors, drill, matching masonry bit and driver or socket.
Lay out the support locations

Follow the approved route and support schedule. Locate hidden services and check required clearances.
Mark the mounting holes

Hold a strap in position and mark the exact fixing locations along the run.
Drill the specified pilot holes

Use the required bit, depth and dust control for the substrate and anchor.
Clean each hole

Follow the anchor maker’s hole preparation instructions before setting a fastener.
Position the conduit and strap

Use the required support during installation and align the strap with the fixing holes.
Seat the anchors and secure the strap

Use the matching drive and stop at the prescribed seating condition. Check that the strap is secure without damaging the conduit.
Repeat along the run

Install each support in the planned location, checking alignment and clearances as you proceed.
Inspect stability and spacing

Verify each attachment and the finished support layout. Complete the required inspection before commissioning.

Electrical work belongs with qualified personnel. Use the approved conduit support pattern and exact anchor instructions.

Vertexa ConcretePro concrete and masonry fastener

Match the anchor and drive to the fixture

Review AnchorMax™ where the substrate and strap detail permit it. Confirm pilot preparation and the correct socket for the specific screw.

Check the connection before you build

Technical planning and quantities

Review connection details, tools, product sizes and a worked quantity example.

Sizes, quantities & full instructions

Plan the fixing. Respect the substrate.

About this guide

Conduit support combines an electrical layout with a masonry connection. Have a qualified person establish the conduit route and required support spacing, then match each strap and anchor to the actual wall. This guide explains the fastening workflow, not electrical wiring.

Technical planning referenceSizes & project data

AnchorMax catalog lengths: 3/16 × 1-1/4 in.; 1/4 × 1-1/4, 1-3/4, 2-1/4, 2-3/4 or 3-3/4 in.; VERTEXA catalog · View product sizes
Strap configuration reference: Atkore lists both one-hole and two-hole EMT straps. Use the listed strap for the actual raceway size and service; count its fixing holes.; Material reference · Atkore Allied EMT strap data

All technical parameters · 7

Size the strap to the raceway and the anchor to the substrate. Electrical support intervals, strap hole count and masonry anchor design are three separate decisions; one does not establish the others.

Read the evidence: VERTEXA catalog = listed product information. Material reference = requirements for the named material/system. Worked example = assumed inputs and arithmetic. Project input = a value to verify for your job.

Parameters, values and supporting evidence
Parameter	Value / method / applicability	Basis & reference
AnchorMax catalog lengths	3/16 × 1-1/4 in.; 1/4 × 1-1/4, 1-3/4, 2-1/4, 2-3/4 or 3-3/4 in.	VERTEXA catalogView product sizes
Strap configuration reference	Atkore lists both one-hole and two-hole EMT straps. Use the listed strap for the actual raceway size and service; count its fixing holes.	Material referenceAtkore Allied EMT strap data
Electrical spacing	Determine raceway type/size, termination distances and support intervals from the adopted electrical requirements and listed system. No single interval covers EMT, PVC and flexible raceways.	Project input
Anchor parameters	Obtain the exact substrate approval, pilot diameter, embedment range, edge/spacing limits and installation torque, if specified. An 8 mm nut setter is not automatically compatible with every AnchorMax head.	Project input
Illustrative length stack	1/8 in. strap + 1/8 in. packer + assumed 1-1/2 in. embedment = 1-3/4 in. geometric length.	Worked example
Separate hole counts	12 one-hole straps need 12 fixing positions; 12 two-hole straps need 24. Add allowance after choosing the actual strap.	Worked example
Services and loading	Check concealed services before drilling. Include filled raceway weight and any applicable vibration, corrosion or seismic requirements in the support design.	Project input

Gather your tools

Approved support layout; utility/rebar detector; tape and level; hammer drill only where permitted for the substrate; exact specified carbide bit and depth stop; approved hole-cleaning equipment; driver and correctly sized bit/socket; silica dust controls and PPE.

Choose the right size

AnchorMax options include 3/16" × 1-1/4" and 1/4" lengths from 1-1/4" to 3-3/4". Confirm the exact product’s substrate approval, pilot diameter, embedment range, edge spacing and installation procedure. Obtain the AnchorMax technical sheet before installation; do not borrow another brand’s drill-bit table.

Compare the relevant products

Step 1: Identify the wall and the complete assembly.

Confirm concrete, solid brick, hollow block or another substrate, including its condition. Locate services and reinforcement. Confirm the conduit route, strap size and required support pattern with a qualified installer.

Tools for this stepTools: Detector, tape, drawings and light.
Size & quantity checkSize / count: Record substrate, fixture thickness and planned positions in inches.

Step 2: Obtain the exact anchor specification.

Match diameter, head, length and corrosion protection to the approved assembly. Total screw length must cover the fixture and spacers plus the specified embedment. Check minimum spacing, edge distance and substrate thickness before marking holes.

Tools for this stepTools: AnchorMax technical sheet, tape and fixing schedule.
Size & quantity checkSize / count: Compare required length with 3/16" × 1-1/4" or the listed 1/4" options. Confirm pilot diameter from AnchorMax data.

Measure from the strap to sound masonry

Drawing explanation & numbered notes

The drawing combines an illustrative 1/8 in. strap and 1/8 in. packer into a 1/4 in. fixture stack. It does not assign an AnchorMax embedment or capacity.

Strap and packer. Include every layer between the head and substrate face.
Sound substrate. Locate the actual masonry face; plaster and voids do not provide the assumed engagement.
Anchor hole. Verify pilot, depth and cleaning using the exact anchor instructions before fastening.

Useful accessory8 mm Magnetic Nut SetterView sizes & details

Step 3: Mark, align and count the fixtures.

Set out conduit straps on the approved route. Hold each fixture flat, check alignment and mark its actual holes. Do not install or work on energized circuits; electrical work belongs to qualified personnel.

Tools for this stepTools: Level, tape, pencil and fixture template.
Size & quantity checkSize / count: Example: 12 two-hole straps = 24 marked anchor holes.

Useful accessoryMini Magnetic Level - 100 mmView sizes & details

Step 4: Drill and clean exactly as specified.

Use the required bit, drilling mode and depth stop for the actual substrate. Follow the anchor’s stated hole depth and cleaning sequence. Control silica dust at the source. Inspect holes before placing anchors; stop if the substrate breaks out.

Tools for this stepTools: Specified drill bit, depth stop, extraction and approved cleaning tools.
Size & quantity checkSize / count: Pilot diameter and hole depth are exact product requirements; do not estimate them from screw diameter.

Count the fixing holes, not just the straps

Drawing explanation & numbered notes

One-hole and two-hole straps are shown functionally; select the listed strap that matches the raceway, environment and support design.

One-hole strap. One required fixing hole gives one anchor position per strap.
Two-hole strap. Two required fixing holes give two anchor positions; do not leave the second empty.
Support locations. Set locations from the actual raceway requirements, including near boxes and changes of direction where required.

Step 5: Seat the fixture without overtightening.

Place the fixture and drive with the specified tool and matching bit/socket. An 8 mm nut setter is suitable only if the selected head measures 8 mm across flats. Stop at the required seated condition without stripping the hole or distorting the fixture.

Tools for this stepTools: Driver and exact-size bit or socket.
Size & quantity checkSize / count: Install one anchor at each scheduled position; use all required holes in the approved detail.

Useful accessory8 mm Magnetic Nut SetterView sizes & details

Step 6: Inspect the fixing and round the order.

Check head seating, fixture contact, alignment and the complete support pattern. Resolve cracked masonry or loose anchors before loading. Use the calculator below for an approved point count; calculate unlike anchor sizes as separate lines.

Tools for this stepTools: Checklist, light, level and quantity calculator.
Size & quantity checkSize / count: Example total with 10% extra: 27 anchors for 24 specified holes.

Work through the numbers

Inches for connection dimensions. Feet only where shown. Round piece and pack counts up; never round required engagement down.

Compare anchor counts

12 one-hole straps × 1 = 12 anchors
12 two-hole straps × 2 = 24 anchors

Assumptions & calculation notes

The strap’s actual listing and support design determine which configuration is suitable; hole count is not a load rating.

Choose the strap before counting the anchors

Apply the purchasing allowance

12 two-hole straps × 2 anchors = 24
ceil(24 × 1.10) = 27

Assumptions & calculation notes

The example assumes every required hole has a suitable anchor. Different substrates and anchor sizes need separate material-list lines.

27 anchors including 10% extra

Inspect before you cover or load it

Acceptance conditions and corrective actions
Check	Accept when	If it fails
Raceway/strap fit	Listed strap fits without crushing or distorting the raceway.	Use the correct strap rather than forcing a small one.
Support layout	Locations follow the applicable raceway requirements and project support design.	Revise the support layout before pulling conductors.
Anchor installation	Approved substrate, hole preparation and head seating verified.	Stop on spinning, cracked masonry or incomplete seating.

Know how much to order.

Takeoff example after the support layout is approved: 12 two-hole straps × 2 anchors = 24 anchors; 10% extra rounds up to 27. Required strap spacing depends on the conduit type, size, route and applicable electrical requirements.

Not sure how the numbers work? Use this quantity calculator, or open the full size & selection calculator.

Open size & selection calculator

Installation references & project-specific requirements

These resources explain general installation principles. Use the current instructions for your exact material, fastener and assembly. Referencing another manufacturer does not imply VERTEXA product approval or compatibility.

Atkore Allied Tube & Conduit — one-hole and two-hole EMT straps; not AnchorMax test data

VERTEXA product listing — concretepro

Catalog options checked 2 November 2026. Worked examples are original arithmetic with stated assumptions. Material references apply to their named systems; they do not certify VERTEXA compatibility or capacity. Use the current issue for the exact assembly and local requirements.

Project questions

Can I choose by screw length alone?

No. Confirm the wall material, strap fixing hole, head fit and required anchor engagement as well as the length.

Where do support positions come from?

Use the conduit system's installation requirements and the applicable project detail. The application photograph is an illustration, not a support-spacing drawing.

Find your fastener

Start with your materials and the connection you need to make.