The End of the Weldon Holder Era

HAIMER’s Safe-Lock is an innovative tool holding system for high-performance machining. The product was developed to meet the rising demands of heavy duty machining, common in the aerospace and mold & die industries. Advanced materials, such as various titanium alloys, are not only lightweight, but also high-strength, corrosion-resistant, and difficult to machine.

Machining these materials is possible by means of high performance cutting (HPC), which generates high cutting forces. These forces often cause the cutting tool to rotate in the tool holder, which can slowly pull the cutting tool out of the chuck. Micro-creep especially applies to tool holders offering precise clamping and good runout accuracy, such as shrink-fit, hydraulic or milling chucks.

Addressing Rotational Forces

A customer will often get a false sense of security when higher holding torques in Nm are cited. Franz Ziegltrum, engineer and Quality Manager at HAIMER, warns: “Unfortunately, the problem is more complicated than that. Pull-out of the cutter cannot be prevented through clamping force alone. The axial and rotational forces combined are too great for frictional clamping alone to overcome. Additional solutions must be put in place to address these rotational forces.”

Known Disadvantages of Weldon Holders

Up to now, with a lack of alternatives, many users have had to resort to conventional Weldon holders, whose clamping screw creates a positive locking mechanism. However, these Weldon tool holders also bring the following known disadvantages: radial runout causing vibration, poor clamping accuracy and balance properties due to the one-sided clamping surface, and a shortened tool life for higher performance cutting tools.

A Better Alternative

The Safe-Lock system combats micro-creep with its patented design, creating an alternative to the negative side effects of machining with a side lock holder. The Safe-Lock principle works like this: spiral-shaped grooves integrate into mating carbide drive pins in the tool holder, combining frictional clamping force and positive locking, and effectively eliminating micro-creep. This allows for increased cutting depths and feed rates and doubles metal removal rates by allowing cutting at higher RPM. Additionally, this unique system provides the best runout accuracy via a naturally concentric design, decreasing tool wear significantly.

On the Safe Side with Safe-Lock

As a member of Partners in THINC, HAIMER provides the Safe-Lock system for use with Okuma machine tools in high performance cutting conditions. It provides pull out protection for shank tools plus the following advantages:

• Highly accurate clamping due to shrink fit technology
• High torque due to form closed clamping
• No loss of accuracy
• No pull out of the tool
• No spinning of the tool
• No damages on workpiece or machine
• Groove on tool shank is directed so that tool will be pulled into the chuck (depending on direction of rotation)
• Patent granted: licensing for cutting tool manufacturers possible
• New: Safe-Lock™ available for shank diameter 6mm, 8mm, 10mm

The New Standard for Roughing Applications

Andreas Haimer, president of the HAIMER Group, provides a succinct summary of this product’s impact on the marketplace: “With the Safe-Lock system, we have established integrated pull out protection for round tools that unites frictional clamping force and positive locking. With regard to process reliability and high material removal rates (MRR), attainable results are much better than when using conventional tool holders. This has been proven by a number of tool manufacturers and end users in practical applications, such that we are convinced that Safe-Lock is on its way to becoming the standard for roughing.”

More: HAIMER provides a Frequently Asked Questions page on their website that offers further insights. You can also see how Safe-Lock addresses challenges in today’s machining in this excellent demonstration video.

Visit HAIMER at IMTS 2016, Booth W-1452.