New chip-breaker offers more choice and accuracy

Pramet aims to increase the accuracy of indexable hole-making with the launch of a versatile new chip-breaker.

Suitable for machining low carbon and soft stainless steels, the SD geometry supports both Pramet’s SCET and XPET ranges.

The SD (soft drilling) chip breaker has been specifically designed to provide improved stability and productivity when drilling low strength soft and long-chipping material, where the balance of forces between the inserts becomes more difficult to maintain.

Part of a wider launch of new products announced by Dormer Pramet in November 2015, the chip-breaker’s positive geometry with stabilizer provides reliable chip evacuation, minimal vibration and low cutting forces. This results in a quieter and more stable machining process.

The addition means Pramet can offer a greater choice of grades, geometries and designs of inserts for indexable hole-making.

Its existing UD (universal drilling) geometry is suitable for machining most medium and high strength steels, while grades D8345, D8330 and D9335 provide a number of options for Pramet’s 800D line of 2D-5D indexable drills.

Marcel Nunes, product manager for indexable hole-making at Dormer Pramet, said: “A key requirement for any indexable drilling task is accurate hole-tolerance and straightness. This is best achieved when the cutting forces on the inner and outer inserts are balanced.

“However, the cutting conditions for both inserts are typically very different. The outer insert cuts smoothly at maximum speed, while the inner insert has to work closer to zero cutting speed, shearing rather than cutting and enduring higher impact forces.

“When this in-balance gets too large the drill starts to move, deflecting it off course. This results in greater vibration and poor-hole quality, unreliable chip evacuation and reduced tool life.

“When machining low strength soft and long-chipping steel and stainless steel the balance of forces becomes even more difficult to maintain. Our new SD chip breaker has been specifically designed to provide better stability and productivity when drilling these materials.””

An overview of all the new indexable ranges launched by Dormer Pramet in November 2015 is available in its latest product brochure. To order a printed copy or for more information contact your local Dormer Pramet sales office.

Watch a video of the new range on our YouTube channel, www.youtube.com/dormerpramet.