Drop In Anchor / Concrete Expansion Anchor (Анкер забивной) – Knurled & Smooth

Product Overview: The Flush-Mount Concrete Solution

Our Drop In Anchors (also known as Female Concrete Anchors, Bullet Anchors, or Multi-Set Anchors) are deformation-controlled expansion fasteners designed for use in solid concrete. Unlike protruding wedge anchors, the Drop In Anchor sits completely flush with the concrete surface, allowing for the insertion and removal of a threaded bolt or rod at any time.

This feature makes it the industry standard for suspending overhead electrical cable trays, HVAC ductwork, and fire sprinkler pipes. The anchor consists of a zinc-plated steel body with internal metric threads and a pre-assembled internal expansion plug (cone).

Russian Name: Анкер забивной (латунный / стальной) / Цанга

Body Style: Knurled (for better grip) or Smooth

Setting Tool: Required for proper installation

Engineering Mechanics & Design

1. Internal Expansion Principle

The magic of a Concrete Anchor lies in its grip. The Drop In Anchor features a split skirt at the bottom.

• The Process: When the internal steel plug is driven down using a specialized “Setting Tool” (punch), it forces the split skirt to expand outwards.

• The Result: This expansion creates immense friction against the walls of the drilled hole, locking the anchor permanently into the concrete base material.

2. Knurled vs. Smooth Body

We offer two distinct body designs to suit different market preferences:

• Knurled Body: Features a diamond-patterned rough surface. This increases the friction between the anchor and the concrete hole during the initial installation, preventing the anchor from spinning (anti-rotation) when you tighten the bolt.

• Smooth Body: Preferred in some markets for its ease of insertion into tight holes.

3. Shallow Embedment Depth

Drop In Anchors are designed for relatively shallow embedment compared to other heavy-duty anchors. This minimizes the risk of hitting reinforcing bars (rebar) buried deep in the concrete, making drilling safer and faster.

Step-by-Step Installation Guide

Correct installation is critical for safety.

1. Drill: Drill a hole into the concrete using a hammer drill and a carbide-tipped masonry bit. The hole diameter must match the anchor’s outer diameter.

2. Clean: Blow out the dust from the hole. Dust acts as a lubricant and can significantly reduce holding power.

3. Insert: Tap the anchor into the hole with a hammer until it is flush with the surface.

4. Set: Insert the Setting Tool into the anchor. Strike the tool with a hammer until the shoulder of the tool meets the top of the anchor. This confirms the plug is fully driven.

5. Fasten: Insert your threaded rod or bolt and tighten to the specified torque.

Technical Specifications

Property	Specification Details
Product Name	Drop In Anchor, Concrete Insert, Bullet Anchor
Russian Name	Анкер забивной стальной (M6-M20)
Material	Carbon Steel (Q235), Stainless Steel (SS304/316)
Internal Thread	M6, M8, M10, M12, M16, M20
Body Length	25mm, 30mm, 40mm, 50mm, 65mm, 80mm
Finish	Yellow Zinc Plated (YZP), White Zinc Plated (Blue)
Lip Type	With Lip (Flanged) or Without Lip (Flush)
Minimum Concrete Grade	C20/25
Standard	Metric / Inch (1/4″, 3/8″, 1/2″)

Application Scenarios

• M&E Services: Suspending threaded rods from ceilings to support air conditioning units.

• Stadium Seating: Fixing removable seats where a flat surface is needed when seats are removed.

• Handrails: Anchoring temporary guard rails that need to be dismantled later.

• Industrial: Securing heavy machinery to factory floors.

Quality Assurance

At HDBolt, we ensure safety through rigorous testing.

• Plug Hardness: The internal expansion cone is heat-treated to be harder than the anchor body. This ensures it expands the body rather than deforming itself during hammering.

• Plating Thickness: Our Zinc plating exceeds 5 microns to prevent rust in damp ceiling voids.

Get a Quote for Wholesale

We export full containers of knurled drop-in anchors to Russia, the Middle East, and South America.

We can package them in small color boxes (100 pcs) or bulk gunny bags. Please Contact Us for a price list including the matching Setting Tools.