The Milwaukee 48-28-4006 Bit Extension 12" is a drilling accessory made to give large-bore bits more reach. This is a bit extension designed for extending the reach of self-feed bits, auger bits, and hole saws during drilling. Model Number 48-28-4006. It is aimed at electricians, plumbers, remodelers, and anyone drilling larger holes where the tool body or work area keeps a standard bit from getting where it needs to go.

The main reason to buy this extension is simple: access. Milwaukee gives you a full 12 inches of added reach, which helps when boring through wall cavities, floor systems, and other spots where a drill cannot sit close to the cut. Instead of changing your whole setup, you keep using the larger drilling accessories you already trust and add the length you need.

This extension uses a 7/16 inch hex shank and accepts 7/16 inch hex accessories. In practical terms, that means it is built for heavier-duty drilling than a small quick-change extension. It is intended for self-feed bits, auger bits, and hole saws 1 inch in diameter and larger with a 7/16 inch shank, so it fits the kind of work where torque transfer and secure engagement matter.

Milwaukee also notes that the 7/16 inch hex fits both three-jaw chucks with 1/2 inch drill capacity and larger, as well as 7/16 inch quick-change chucks. That gives the accessory some flexibility across different drill setups. If you already run Hole Hawg, Super Hawg, or other larger drill products, this kind of interface is the right match for the job instead of trying to force a lighter-duty extension into heavier drilling work.

On the accessory side, the extension is designed to work with most 7/16 inch shanks, with or without a power groove, and Milwaukee states that hole saws and arbors are interchangeable with most other brands. That is useful if your accessory drawer is not all one brand. You can keep the drilling system you already use and add reach without rebuilding the whole setup.

The Milwaukee 48-28-4006 Bit Extension 12" is a smart buy for tradespeople drilling larger-diameter holes in wood and similar materials where clearance is tight and reach is the real problem. If you mostly run small twist bits, this is overkill. If you regularly use self-feed bits, auger bits, or larger hole saws and need to get deeper into the work, it is the right kind of extension to keep on hand.

Milwaukee 48-28-4006 Bit Extension 12" is the right fix when reach is the problem

This is a simple accessory, but for the right user it solves a very real jobsite headache without complicating the setup.

• Who it's for: Pros using self-feed bits, auger bits, and larger hole saws in tight framing, rough-in, and remodel work.
• Why it stands out: You get a true 12-inch extension, a 7/16 inch hex interface, and compatibility with the larger drilling accessories that actually put extensions to work.
• Worth knowing: This is not a general-purpose small-bit extender. It is meant for bigger drilling accessories and the drills that can run them properly.

• What type of accessory is this? This is a bit extension for extending the reach of 7/16 inch hex drilling accessories.
• What bits does it work with? It is designed for self-feed bits, auger bits, and hole saws 1 inch in diameter and larger with a 7/16 inch shank.
• What tools can drive it? The 7/16 inch hex fits three-jaw chucks with 1/2 inch drill capacity and larger, as well as 7/16 inch quick-change chucks.
• Does it work only with Milwaukee accessories? No. Milwaukee states it works with most 7/16 inch shanks, with or without a power groove, and that hole saws and arbors are interchangeable with most other brands.