A Really, Really Big Boring Bar

The developers are calling it the world’s largest anti-vibration boring bar—one that is capable of machining a bore 12 inches in diameter and as long as 165 inches. The bar itself is 240 inches long and is designed for a lathe that is 66 feet long. Sandvik Coromant designed and manufactured this record-breaking boring bar in cooperation with lathe builder Gurutzpe Turning Solutions.

Gurutzpe, headquartered in Itziar-Deba in the Basque region of northern Spain, is one of the largest manufacturers of heavy horizontal lathes in Europe. When a customer ordered the 66-foot lathe, specifications called for an integrated boring capacity of unprecedented dimensions. To meet this requirement, the lathe builder turned to Sandvik Coromant Ibérica, the division of Sandvik Coromant serving that territory.

These two entities entered into an agreement guaranteeing the customer technical support for the lathe and the operation of the boring bar as a comprehensive solution. Another unit of Sandvik Coromant in Teeness, Norway, handled the final design and construction of the anti-vibration boring bar. Cooperation between Teeness and Gurutzpe also encompassed the design of the clamp for the machine.

Production time for the bar was four months; total project time from order to delivery was eight months.

Here are the facts and figures about the anti-vibration boring bar:

• Length: 240 inches
• Capacity of the bore: 165 inches
• Overhang: 14 times the diameter
• Biggest challenge: Being able to machine lengths of up to four meters without having problems with vibrations and maintaining good surface quality
• Diameter: 12 inches

For a more detailed account of this remarkable boring bar, click here.