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October 19, 2018

Achieving perfect concentricity with the SRT Reamer

SRT Reamer

The SRT, or Super Round Tool, is a patented reamer designed by the Northern Tool division of Star Cutter Company to create the best quality reamed hole across a spectrum of applications.  Its combination of straight and helical flutes drives the tool to center and keeps it there for the duration of the cut.

The SRT’s abilities include:

  • Superior surface finish (Ra, Rz, and Rmax)
  • Near perfect concentricity
  • Roundness deviations less than 2 µm

Originally designed as a powdered metal valve guide reamer it now services countless applications where finish and position are critical. The SRT is available in right hand spiral – right hand cut for blind hole applications and left hand spiral – right hand cut for chip forward flushing in open holes. Through manipulation of the straight flute position relative to C/L, helix, and rake angles it is possible to adjust the shear forces created.  This enables the SRT to finish a diverse group of materials.

Another benefit of the SRT is the innate ability to create its own path, straightening an often inferior pre-existing or rough drilled hole. The combination of flute style and position also allows it to correct roundness issues that may be present as a result of sintering, casting, or pre-machined bores. The flute density (3 X 3 or 5 X 5) improves cycle time dramatically and can eliminate the need for post ream operations such as honing, lapping, or roller burnishing.

Some successful applications include:

  • Compacted Graphite Iron (CGI)
  • Austempered Grey Iron (AGI)
  • Ductile Iron
  • Powdered metal (resin and oil impregnated)
  • Alloyed Steels
  • Titanium
  • High temperature Nickel alloys
  • Aluminum
  • Brass
  • Industrial plastics

If finish hole quality and speed of operation are required, consider the patented SRT for all your reaming needs.


Gary McCarel, Application Engineer

Click here for more information on the SRT Reamer


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