DIN 6388B OZ Collets | EOC Heavy Duty Milling Collets

Product Overview

When it comes to heavy roughing, large diameter end milling, and aggressive feed rates, standard collet systems can sometimes struggle with tool slippage or pull-out. The DIN 6388B OZ Collet (EOC Collet) is engineered specifically for these demanding applications. Its defining feature is the shallow 1:10 (approximately 5.7 degrees) taper angle. This long, gradual taper creates a massive mechanical advantage, translating the tightening torque of the collet nut into an immense, 360-degree radial gripping force along the entire shank of the cutting tool. This makes the OZ collet system the preferred choice for heavy-duty CNC milling chucks.

Key Features & Advantages

• Massive Gripping Force: The 1:10 taper design provides superior clamping power compared to the 8-degree taper of ER collets, making it virtually impossible for tools to slip or pull out during heavy cuts.

• High Precision & Rigidity: The extended gripping length ensures excellent concentricity and rigidity. Standard precision is ≤ 0.015mm, with high-precision versions (≤ 0.008mm) available for demanding tolerances.

• Premium Spring Steel: Manufactured from high-quality SUJ2 or 65Mn spring steel, hardened to HRC 44-48, and cryogenically treated to maintain elasticity and resist wear over thousands of clamping cycles.

• Double-Slotted Design: The DIN 6388B standard features slots from both ends, allowing the collet to collapse uniformly parallel to the tool shank for maximum contact area.

• Broad Clamping Range: Each collet typically offers a collapse range of 0.5mm to 1.0mm, allowing it to clamp both metric and imperial tool shanks securely.

Why Partner with Pingyuan Zhenghao Machinery?

• Direct Manufacturer Savings: Bypass trading companies and source heavy-duty milling collets directly from our factory for highly competitive wholesale pricing.

• Comprehensive Size Range: We manufacture the full spectrum of OZ/EOC collets to fit your heavy-duty chucks:

• OZ16 (EOC16): Clamping range 2.0mm - 16.0mm

• OZ25 (EOC25): Clamping range 2.0mm - 25.0mm

• OZ32 (EOC32): Clamping range 3.0mm - 32.0mm

• Strict Quality Control: Every single collet is inspected using high-precision optical comparators and runout gauges before packaging to guarantee performance.

• Complete Tooling Solutions: We also manufacture the corresponding BT, SK, and NT Heavy Duty OZ Milling Chucks and specialized ball-bearing clamping nuts to provide a complete, guaranteed-accuracy system.

Frequently Asked Questions (FAQ) - Selection Guide

Q1: What is the difference between an OZ collet and an ER collet?

A: The main difference is the taper angle and application. ER collets have an 8-degree taper, offering a wider collapse range (up to 1mm or 2mm) and are great for general-purpose milling, drilling, and tapping. OZ collets (DIN 6388B) have a shallower 1:10 (approx. 5.7-degree) taper. This provides a much higher gripping force and rigidity, making them superior for heavy roughing and aggressive milling where tool pull-out is a concern.

Q2: Are OZ collets and EOC collets the same thing?

A:Yes. "OZ" and "EOC" are different naming conventions for the exact same DIN 6388 standard collet. For example, an OZ25 collet is dimensionally identical to an EOC25 collet.

Q3: Can I use an OZ collet in an ER collet chuck?

A:No. The taper angles and physical dimensions are completely different. An OZ collet must be used in a chuck specifically designed for OZ/EOC collets (which has a matching 1:10 internal taper).

Q4: What is the clamping range of an OZ collet?

A: While they have immense gripping force, OZ collets generally have a smaller collapse range than ER collets. Most OZ collets have a collapse range of 0.5mm (for smaller sizes) to 1.0mm (for larger sizes). For maximum gripping force and runout accuracy, it is always recommended to use the exact size collet for your cutting tool shank.

Eliminate tool pull-out and maximize your material removal rates with our Heavy-Duty DIN 6388B OZ / EOC Collets.

Contact our sales team today for a complete catalog, sizing assistance, and bulk pricing.