BBT40 SLN/SLA Weldon End Mill Holders | Dual Contact | SLN16 SLN20 SLN25

Product Overview

When performing heavy roughing or machining hard materials like titanium and Inconel, standard collet chucks often struggle with tool slippage or pullout. The SLN/SLA Weldon Tool Holder solves this by using a solid set screw that locks directly into the flat on the shank of a Weldon end mill, providing a 100% positive, slip-free drive. By combining this ultra-secure clamping method with the BBT (Dual Contact) spindle interface, this holder delivers massive improvements in radial rigidity. The dual-contact design eliminates the "bell-mouthing" effect at high speeds and heavy loads, drastically reducing chatter, improving surface finish, and extending the life of your expensive cutting tools.

Key Features & Advantages

• BBT Dual-Contact Technology: Unlike standard BT shanks that only contact the spindle taper, the BBT shank contacts both the taper and the spindle face simultaneously. This significantly increases the rigidity of the tool assembly, especially during heavy side-milling operations.

• 100% Positive Drive (Weldon/Side-Lock): The SLN/SLA design utilizes high-strength set screws that tighten against the flat on the cutting tool's shank. This mechanically prevents the end mill from spinning or being pulled out of the holder during aggressive roughing cuts.

• High-Precision Bore: The internal bore (e.g., 16mm, 20mm, 25mm) is precision-honed to a tight H4 tolerance, ensuring excellent concentricity and minimal runout for accurate machining.

• Heavy-Duty Construction: Forged from premium 20CrMnTi alloy steel, case-hardened to HRC 56-58, and precision-ground. The thick-walled design of the holder body provides maximum mass to dampen vibrations.

• Coolant Options: Available in standard solid designs or with Coolant-Through (AD/B) capabilities, allowing high-pressure coolant to flow directly through the tool or along the tool shank for superior chip evacuation and cooling.

Why Partner with Pingyuan Zhenghao Machinery?

• Direct Manufacturer Savings: Source premium dual-contact heavy milling holders directly from our factory, bypassing trading companies for highly competitive wholesale pricing.

• Comprehensive Size Range: We offer a full range of SLN/SLA metric sizes (from SLN6 up to SLN40) and fractional (inch) sizes to accommodate any Weldon shank end mill.

• Dynamic Balancing: All BBT40 SLN holders are dynamically balanced to G2.5 @ 20,000 RPM (or custom specifications), ensuring smooth operation and protecting your machine's spindle bearings at high speeds.

• Strict Quality Control: Every holder undergoes rigorous 3D CMM inspection for taper accuracy (AT3), face squareness, and bore runout before shipment.

Frequently Asked Questions (FAQ) - Selection Guide

Q1: Can I use a BBT40 tool holder in a standard BT40 spindle?

A:Yes, but with a caveat. A BBT40 holder will fit into a standard BT40 spindle, but it will function just like a standard BT holder (only contacting the taper). To get the "Dual Contact" benefit (taper and face contact), your CNC machine must be equipped with a BBT (Dual Contact) spindle.

Q2: What is the difference between SLN and SLA?

A: Both refer to side-lock (Weldon) end mill holders. SLA typically refers to the standard side-lock holder design, while SLN often denotes a holder with internal coolant delivery (coolant-through) capabilities or a specific regional naming convention. Functionally, they both use set screws to lock onto the flat of the tool shank.

Q3: Can I hold a standard cylindrical shank (without a flat) in this holder?

A:No, it is highly discouraged. The set screw in an SLN/SLA holder is designed to seat perfectly flat against the Weldon flat on the tool shank. If you tighten the set screw against a round shank, it will score the tool, provide very poor clamping force, and the tool will likely slip or pull out during machining. For round shanks, use a high-precision collet chuck or a milling chuck.

Q4: Do these holders come with the locking screws?

A:Yes. All our SLN/SLA Weldon tool holders come complete with the appropriate high-strength, precision-ground set screws. We also offer replacement screws if needed.

Eliminate tool pullout and maximize your heavy milling performance with our BBT40 SLN/SLA Weldon End Mill Holders.

Contact our sales engineering team today for a complete catalog, balancing options, and bulk pricing.