5/16 in-18 Stainless Steel Drop In Anchors (100 pcs) - Durable

In this review the reviewer looks at a bulk pack of 100 knurled drop in anchors intended for solid concrete. The bottom line is simple: this set is for installers, contractors and DIYers who need a reliable, corrosion resistant anchor in quantity and value the long term hold of stainless steel. The single biggest reason to buy is durability - these anchors are made from premium stainless steel and are designed to grip solid concrete when expanded with the proper set tool.

Key Features

• Package include: One package contains 100 pieces, providing enough anchors for multiple projects or for keeping spares on hand for repairs.
• Material quality: Made from stainless steel that resists corrosion and rust, which helps anchors remain secure in concrete over time.
• Designed dimensions: Each anchor is sized for a 1-1/4 in hole depth with a 3/8 in hole diameter and works with 5/16-18 bolts, ensuring compatibility with common fasteners.
• Function: The knurled body and internal forced expansion design let the insert expand and embed into solid concrete for a tight mechanical hold.
• Common use: Intended for solid concrete and suitable for use with machine screws, bolts and threaded rod to anchor fixtures reliably.
• Installation steps: Simple three-step process of pre-drilling, inserting knurled side down and using a set tool to expand the anchor for a secure fit.

Who It's For

This pack suits builders, maintenance teams and homeowners who regularly anchor fixtures to solid concrete and want a corrosion resistant option that comes in bulk. It is particularly useful where a consistent, mechanical expansion anchor is required for medium duty loads and when a quantity of identical anchors is needed to complete several mounting points.

Those who should look elsewhere include users anchoring into hollow block or drywall, since these drop in anchors are designed for solid concrete only, and anyone who cannot access or afford a simple set tool, which is recommended to seat the anchor correctly.

Pros & Cons

Pros

• Good value for quantity, supplying 100 anchors to cover large jobs or spare needs.
• Stainless steel construction offers corrosion resistance for longer life in concrete.
• Knurled, forced expansion design produces a firm mechanical hold when installed correctly.

Cons

• Installation requires the correct set tool; some users may find this an extra purchase or step.
• Not suitable for hollow or nonconcrete substrates, limiting versatility.

Specifications

Our Verdict

These 5/16 in-18 stainless steel knurled drop in anchors are a sensible purchase for anyone installing fixtures into solid concrete who needs corrosion resistant anchors in bulk. They offer dependable expansion holding and strong stainless steel construction, making them good value for contractors and serious DIYers, provided the installer has or can obtain the correct set tool.

Frequently Asked Questions

Do these anchors work in hollow block?
No. These knurled drop in anchors are designed for solid concrete and will not expand properly in hollow substrates.

What bolt size is used with these anchors?
They are intended for use with 5/16 in-18 bolts or compatible machine screws and threaded rod.

Is a special tool required to install them?
A set tool is recommended to drive the thinner part into the anchor and hammer the back so it expands and embeds securely in the concrete.