Teledyne Firth Sterling SI-MCLNL-254F Indexable Boring Bar – Used in Great Condition

Professional-grade indexable boring bar / lathe tool holder manufactured by Teledyne Firth Sterling (visible original sticker on the head). This is a high-quality American-made metalworking tool designed for precision internal boring, turning, and facing operations on manual or CNC lathes.

Key Markings & Identification

• Engraved model: SI MCLNL 254F
• Teledyne Firth Sterling logo sticker clearly visible
• Part of the well-regarded SI-MCLNL series of indexable holders (comparable to TMX / Toolmex versions of the same family)

Specifications & Features (based on visual inspection of the tool and extensive research of the MCLNL series)

• Style: MCLNL – Indexable holder for negative-rake 80° diamond CNMG-series carbide inserts (commonly CNMG-432, CNMG-543, and similar sizes depending on exact pocket geometry)
• Configuration: Left-hand / negative lead angle style (typical for MCLNL designation; often -5° lead)
• Shank: Round steel shank suitable for boring heads, tailstocks, or tool posts (approximate diameter 1-1/4" / 32 mm based on visual scale with hand and comparable tools in photos)
• Overall Length: Approximately 8.5–9.5 inches (exact measurement should be confirmed by buyer; consistent with mid-size SI-MCLNL boring bars)
• Insert Holding: Precision-machined pocket with lever/pin-style top clamp secured by screw for secure, rigid insert retention during heavy cuts
• Mounting Features: Multiple threaded holes and through-hole at the head for set screws, mounting, or coolant delivery (where applicable)
• Rake: Negative rake design for strength and versatility across a wide range of materials (steel, stainless, cast iron, aluminum, etc. – insert grade determines suitability)
• Condition Details: Excellent working condition. Minor surface scratches, light shop grime in recesses (easily cleaned), and normal wear marks on the shank. No broken components, stripped threads, or damaged pocket. Clamp mechanism operates smoothly.

What’s Included

• 1 × Teledyne Firth Sterling SI-MCLNL-254F indexable boring bar (as shown in photos)
• No insert included
• No original packaging or documentation

Applications Ideal for machinists, tool & die shops, maintenance departments, CNC lathe operators, or serious hobbyists. Excellent replacement or backup tool for production or prototype work. The robust steel construction and quality clamp design provide reliable performance even in demanding environments.