Pagnoni OZ Collet Chucks with SK Taper

Available Sizes and Part Numbers

Purpose and Application

Pagnoni OZ (EOC) SK series collet chucks are designed by the Italian company Pagnoni Tools SRL for installation on CNC milling machines and machining centers with SK spindles according to the ISO 7388-1 (DIN 69871) standard. The primary purpose of the OZ system (DIN 6388 / ISO 10897) is performing roughing, semi-finishing, and heavy-duty milling operations with high stock removal rates, where increased clamping rigidity and reliable retention of large diameter tools are required.

Design and Features

The clamping taper conforming to the DIN 6388 standard (collet taper angle 1:10 / 2°52') features a longer contact length compared to standard ER chucks, providing increased clamping force and high resistance against tool pull-out under load. The chucks are manufactured from alloyed case-hardened steel with HRC 58±2 hardening (case depth 0.4–0.5 mm). Threads and chamfers are executed after heat treatment. The body surface undergoes bluing, and the mounting taper is precision ground to accuracy < AT3 (DIN 7187 / DIN 2080). All chucks undergo 100% outgoing quality control and are hardened for stable operation with balancing class G 6.3 at 12,000 rpm. They are supplied with GHROS clamping nuts and an internal clamping screw.

Compatibility

Tooling is designed for machine spindles with SK 40 and SK 50 tapers (ISO 7388-1 / DIN 69871). Compatible with standard OZ (EOC) system clamping collets according to DIN 6388 B / ISO 10897 B standards in sizes EOC 16 (OZ 16), EOC 25 (OZ 25), and EOC 32 (OZ 32). Spindle retention is achieved via pull studs conforming to DIN 69872 (e.g., Pagnoni 940TIR01, 950TIR01).

Selection Parameters

Model selection is based on spindle taper size (SK 40, SK 50) and OZ (EOC) collet size:

• EOC 16 / OZ 16: shank clamping 2–16 mm, nut outer diameter D = 43 mm;
• EOC 25 / OZ 25: shank clamping 2–25 mm, nut outer diameter D = 60 mm;
• EOC 32 / OZ 32: shank clamping 3–32 mm, nut outer diameter D = 72 mm.

Regarding projection length H (LPR), standard versions (70 mm for OZ 16/25, 80 mm for OZ 32) and extended modifications (100 mm and 130 mm) are available. Coolant supply is implemented in Form AD/B execution (universal supply through center or flange).

Key Advantages

• Increased Clamping Force: DIN 6388 collet taper (1:10) ensures high clamping rigidity during heavy-duty milling operations.
• Taper Accuracy < AT3: precision ground taper surface guarantees tight spindle contact and protection against wear.
• Material Wear Resistance: alloyed case-hardened steel with HRC 58±2 hardness ensures long service life.
• 100% Quality Control: complete individual inspection of each production unit at the Pagnoni factory in Italy.
• Extended Projection Options: availability of modifications with projection H up to 130 mm allows machining of deep workpiece features.