Tru-Stone Technologies of Waite Park, Minnesota joined The L.S. Starrett family of companies in May of 2006. Tru-Stone is a leader in custom engineering and manufacturing of high-precision granite machine bases and accessories for major producers of semiconductor, flat panel display, advanced microelectronics, aerospace, automotive, medical, optical and general industrial products. Tru-Stone is highly valued by its customers for providing excellent service and technical engineering. 

"We're excited about the acquisition of Tru-Stone and the strategic fit that it provides our Company,” Starrett President and CEO Douglas A. Starrett commented. “Tru-Stone will dovetail nicely with our existing business and fits our reputation for providing the finest in precision measuring instruments that meet the industry's most stringent demands.

Tru-Stone brings to our Company 46 years of developing proprietary processing and finishing techniques, which has earned them recognition as the leading industry provider of high precision, custom requirements using granite as a primary material,” continued Mr. Starrett, “and we are proud to add Tru-Stone Technologies to the Starrett portfolio.”

Starrett's existing granite surface plate and accessories business has now been combined with Tru-Stone assets, with manufacturing and technical support located at the Waite Park, MN facility.

Unequaled Experience and Expertise
Starrett Tru-Stone offers unequaled experience and expertise in building special, extra-large granite surface plates and custom products from granite to meet specific requirements. Another specialty is the design, manufacture and assembly of very close tolerance work-holding and special gaging. Quoted on an individual basis, the form and usage of Starrett Tru-Stone special granite products is limited only by the imagination of the creative tool designer.

Tru-Vac Vacuum Chucking
One of Starrett Tru-Stone's core technologies is Tru-Vac Vacuum Chucking – standard and custom solutions for vacuum chucking, positioning or air-lift part transfer. Tru-Vac technology integrates the stability and precision flatness of granite with a porous medium, usually ceramic. By utilizing vacuum draw at specific locations or distributed over the entire surface of the workpiece, the need for mechanical clamping with its inherent part distortion and risk of damage can be eliminated.

Tru-Vac technology can be utilized in air chucks smaller than a hockey puck or larger than a conference room table. Vacuum zones can be of nearly any shape by virtue of Starrett Tru-Stone's CNC milling capabilities. Multiple zones can be utilized to accommodate a variety of part sizes or even to provide a combination of negative and positive pressure for controlled part movement.

A Broad Range of Custom Capabilities and Value-Added Assembly
Starrett Tru-Stone's wide variety of technical capabilities also include drilled and bored holes with precise size and location, inserts turned and inspected in-house for quality control and custom options, T-slots and inserts bonded using proprietary methods, CNC milling of slots and clearance areas, and unsurpassed dimensional control of flat, square, and parallel surfaces.
Starrett Tru-Stone technicians are also skilled at value-added assembly including the addition of bearing rails, encoder rails, screw drives, stages, or vibration damping devices.