These 3/8" drop in Sanko anchors are great for heavy materials like concrete. Box of 50 concrete anchors.

The most trusted name in core drilling anchors. A recent study shows that Sanko anchors are 15% stronger than the competition Versatile - will work with bolts and threaded rod in any length Recessed - drill the hole the same length as the anchor for a flush finish. Drill deeper for more embedment into masonry projects If anchor is no longer needed, simply plug or fill with cement to make the surface smooth again For proper installation, we recommend the use of our setting tool Values shown on the chart are average ultimate values and are offered only as a guide and are not guaranteed. A safety factor of 4:1, or 25%, is generally accepted as a safe working load. The concrete compressive strength should be 2,987 psi Inside threads are machine rolled rather than cut for superior holding strength Landed Price: $0.2 / anchor

CT-3040U | Drop-in anchors are internally threaded controlled expansion fasteners with an expansion plug.  They are suitable for flush mounting applications in solid base materials like concrete.  The anchor is set by driving the expansion plug towards the bottom of the anchor using a setting tool

Specifications
Inside Thread 3/8"
Thread Length 5/8"
Outside Diameter x Length 1/2" x 1-9/16"
Drill Bit Diameter 1/2"
Embedment Depth 1-9/16"
Tension Load 3,307 (lbs)
Setting Tool Required HT-3040 (Free w/ Carton Purchase)
Box Quantity 50
Carton Quantity 1,000