These are diamond core drill bit barrels (also commonly referred to as core drill bits or hole saw barrels for concrete and masonry drilling). They feature a threaded nut on top for mounting onto a core drilling machine or heavy-duty power drill, and are designed for heavy construction tasks like cutting clean cylindrical holes through reinforced concrete, stone, brick, or block.
Key Features Visible:
Threaded Connection Hubs: Standard female thread connection on the top head for fast attachment to spindle arbors.
Mesh & Bubble Wrap Packaging: Protective plastic mesh sleeves and bubble wraps around the body/cutting edges to prevent diamond segment damage during transport.
Varying Diameters & Lengths: The image shows multiple sizes—thicker diameter bits wrapped in bubble wrap on the left/back, and slimmer, longer bar