To choose the right FAMAG 1639 Forstner Bit Extension, start by checking the shank diameter of your current cylinder boring bit or forstner bit—it needs to be between 8 and 13mm. The extension comes in four sizes: 8mm, 10mm, 12mm, or 13mm inner diameter, so you'll want to match your bit’s shank size exactly to the extension size for a secure fit. If you’re using Famag Bormax forstner bits, just find the corresponding extension size from our list. The four clamp screws and three machined flats ensure your bit is held securely and runs true, virtually eliminating wobble even with longer extensions. If you’re not sure about your bit’s size, measure the shank with calipers or consult your bit’s specifications. Feel free to reach out to our support for help in selecting the perfect fit.

To pick the right FAMAG 1639 Forstner Bit Extension, first measure the shank diameter of your drill bit or Forstner bit—these extensions fit shank sizes of 8mm, 10mm, 12mm, or 13mm. Match your bit’s shank size to the extension’s specified inner diameter. For example, use the 8mm version for a bit with an 8mm shank. Also, consider the drilling depth you need: the Famag 1639 comes in 80mm, 125mm, 250mm, and 400mm lengths. These extensions are perfect for deep hole drilling and are specifically compatible with Famag Bormax Forstner bits. Double-check both the diameter and length before ordering for a perfect fit!

Installing the FAMAG 1639 Forstner Bit Extension is quick and hassle-free. First, loosen the four clamp screws on the extension, then insert your bit’s shank so its machined flats align with the clamps. Tighten the screws evenly to secure the bit — the precision-ground interior and three flats guarantee a stable, centered hold with minimal run-out. When drilling deep holes, run your drill at a moderate speed, and pause periodically to clear wood chips for optimal performance and bit longevity. Always check that the bit and extension are tightly fastened before use. These extensions are made from hardened tool steel, offering exceptional stability, accuracy, and durability.

Absolutely! The FAMAG 1639 Forstner Bit Extensions are built with durability in mind, constructed from hardened tool steel for reliable strength even under demanding tasks. The four robust clamp screws hold your drill bit tight, and the three machined flats prevent slipping or misalignment during operation. To maintain lasting performance, periodically inspect and tighten the screws, clean out wood chips, and check for wear. With proper installation and care, you’ll enjoy precise, wobble-free deep hole drilling time after time. These extensions are trusted for both professional woodworking and serious DIY projects.