Carbatec 150mm Tri-Grind Forstner Bit Extension

Carbatec 150mm "Tri-Grind" Forstner Bit Extension — One Shank That Does It All

Tackling deep recess drilling? This 150mm "Tri-Grind" Forstner Bit Extension gives you the reach you need, with a clever shank design that performs brilliantly no matter how you mount it. It's a true best-of-both-worlds solution, engineered to grip securely whether you're working in a chuck, a collet, or a grub screw mount.

The magic is in the "Tri-Grind" shank itself. Three flat facets deliver superb non-slip, torquey grip in a standard 3-jaw drill chuck. The three rounded faces between them self-centre beautifully in a collet-style chuck, while in a 10mm bore grub screw mount, the flat face gives the grub screws something solid to bite, and the opposing rounded face sits flush against the bore for true-centre every time.

Key Benefits

• Versatile "Tri-Grind" shank — grips securely in a 3-jaw chuck, self-centres in a collet chuck, and seats true in a grub screw mount, so it performs no matter your setup.
• 150mm drilling extension capacity for sinking Forstner bits deep into your turning and boring projects (overall length is longer).
• 10mm bore with twin large grub screws for a firm, confident hold on your bits.
• 8mm sleeve with twin grub screw holes to suit smaller shank bits with ease.
• Broad compatibility with 10mm or 8mm shank Forstner bits, standard round shank or "Tri-Grind", as found on our Tungsten Carbide Tipped Forstner bits.
• Stackable design — use it on its own, or stack it inside another extension for extra-long drilling reach.

Main Applications

• Deep recess and hollow form drilling on the lathe
• Salt and pepper grinder bodies, vases and vessels
• Boring with 10mm or 8mm shank Forstner bits in a drill chuck, collet chuck, or grub screw mount
• Extra-long drilling when stacked with a second extension

Whatever your chuck or mount, this extension grips properly and bores true — so you can focus on the work, not the setup. Reach deeper into your most ambitious projects and add the "Tri-Grind" Extension to your kit today.

NB: For use with a minimum 22mm diameter bit, to clear the head. These extensions are not designed for 3/8" (9.5mm) shank bits — if that's what your Forstner bits require, take a look at our ER-16 Series Extensions instead.