PHASE 2, 12" 3-Jaw Chuck 4" Hole Self Centering Jaws

The PHASE II 12-Inch 3-Jaw Self-Centering Lathe Chuck with 4" Through-Hole is a high-quality, heavy-duty workholding solution designed for precision turning, facing, and machining operations. Built for professional machinists, production shops, and industrial environments, this chuck delivers reliable accuracy, strong clamping force, and efficient setup for repetitive and large-diameter workpieces.

Precision Self-Centering 3-Jaw Design

This chuck features self-centering jaws driven by a precision scroll mechanism, allowing all three jaws to move simultaneously. This design ensures fast, repeatable centering of round and hex stock, significantly reducing setup time compared to independent jaw chucks while maintaining excellent concentricity.

Large 12" Diameter with 4" Through-Hole

The 12-inch chuck diameter provides a wide gripping range for medium to large workpieces, while the 4-inch through-hole allows bar stock and long material to pass through the spindle—ideal for production turning and continuous machining operations.

Heavy-Duty Construction & Durability

Manufactured from high-quality cast iron or semi-steel (model dependent), this PHASE II chuck is precision-machined, hardened, and ground to withstand demanding workloads. The robust body and hardened jaws ensure long service life, consistent clamping force, and resistance to wear in industrial shop environments.

High Accuracy & Clamping Performance

Precision-machined scroll and jaw guides deliver smooth jaw movement, reliable gripping, and stable performance under load. The chuck is designed to maintain concentricity and minimize runout for improved surface finishes and machining accuracy.

Ideal Applications

• Engine lathes and CNC lathes
• Production machining and repetitive turning
• Holding round and hex stock
• General metalworking and fabrication
• Automotive, industrial, and manufacturing shops

Key Features & Benefits

• 12" Chuck Diameter – Supports larger workpieces
• 3-Jaw Self-Centering Design – Fast setup and repeatable accuracy
• 4" Through-Hole – Allows pass-through of long bar stock
• Precision Scroll Mechanism – Smooth, synchronized jaw movement
• Hardened Jaws – Long-lasting grip and durability
• Heavy-Duty Construction – Built for professional and industrial use
• PHASE II Quality – Trusted performance at excellent value

Specifications

• Brand: PHASE II
• Chuck Type: 3-Jaw Self-Centering Lathe Chuck
• Chuck Diameter: 12 inches
• Through-Hole Diameter: 4 inches
• Jaw Type: Self-centering, reversible (model dependent)
• Body Material: Cast iron / semi-steel
• Mounting: Requires compatible back plate (sold separately unless specified)
• Application: Engine and CNC lathes

Why Choose This PHASE II 12" 3-Jaw Chuck?

The PHASE II 12" 3-Jaw Self-Centering Chuck with 4" Hole offers an ideal balance of precision, durability, and value. Its large capacity, reliable self-centering action, and heavy-duty construction make it an excellent choice for shops that demand efficient setup, consistent accuracy, and dependable workholding for everyday machining tasks.

Whether you’re upgrading existing equipment or outfitting a new lathe, this chuck delivers professional-grade performance at a competitive price.

A PHASE 2,  12" 3-Jaw Chuck 4" Hole with Self Centering Jaws In good condition.