The FAMAG 1639 Extension Set lets you transform standard cylinder boring bits and any tool with an 8 or 10 mm shank into deep-hole drilling powerhouses. Crafted from hardened tool steel with precision-ground run-out, each rod secures your bit via four 120°-spaced clamp screws and three machined flats for perfect concentricity. Housed in a wooden storage case, these extensions simplify long-reach tasks in cabinetry, turnery, and general woodworking.

📏 Technical Specifications

• Inner Diameter (ID): 8 mm set or 10 mm set

• Overall Lengths (GL): 80 mm, 125 mm, 250 mm (three-piece set)

• Usable Length (NL): GL minus clamp-block height (~NL = GL–40 mm)

• Clamp System: Four hardened-steel screws at 120° intervals

• Shaft Flats: Three milled surfaces for zero-slip run-out

• Material: Hardened, corrosion-resistant tool steel

• Storage: Custom wooden case with foam inlay

🎯 Key Benefits

• Extended Reach: Drill beyond standard bit length for deep mortises, dowel holes, and lathe hollowing.

• Precision Alignment: Clamp screws and shaft flats eliminate wobble, ensuring clean, tear-free holes.

• Versatile Compatibility: Works with all cylinder boring bits and accessories sporting an 8–13 mm shank.

• Durable Construction: Hardened tool steel resists bending and wear, even under heavy loads.

• Organized Storage: Wooden case protects components and keeps your workshop tidy.

⚙️ Application Tips

1. Select the Correct Extension: Match ID to your bit’s shank diameter before mounting.

2. Secure the Bit: Insert the bit fully, then tighten all four clamp screws in alternating sequence.

3. Balance Speed & Feed: Reduce RPM slightly when using longer extensions to maintain stability.

4. Clear Chips Regularly: Periodically retract and clear swarf to prevent binding in deep holes.

5. Inspect & Maintain: Check run-out on a dial gauge and re-tighten screws before each use.