Alliant Metals Inc. Centerless Grinding Services for Achieving Fine Finish

Centerless grinding is an effective method of precision grinding the outside diameter of any cylindrical shape such as round bar, tube, pipe, pins, mixer shafts and pump shafts. We can grind stainless steel, nickel alloy, tool steel, carbon, alloy steels, aluminum, brass, bronze, high temp metals, etc.

Alliant Metals Inc. has the ability to centerless grind round bar stock up to 6 inches in diameter and 14 feet long on our Cincinnati Twin Grip through-feed grinder. Centerless grinding is the process that feeds a bar into the grinding machine between the grinding wheel and regulating wheel. The work blade which is a carbide-tipped strip of steel holds the bar at the correct height. This allows for roundness and diameter tolerances of the bar. As both wheels rotate, it pulls the bar past the grinding wheel without any external feeding mechanism. To produce straightened ground bar, Alliant passes its round bar through a straightening machine. Using dial indicators to find where the bar is curved or bent a hydraulic ram forces it in line. Straightness is measured in deviation over a certain length which may require a series of pass-thrus on the centerless grinder.

Machine shops may require straighter bars because it prevents vibrations on CNC Machines therefore allowing jobs to complete faster. Precise diameters of very round stock can eliminate tool breakage allowing for tighter machining tolerances. Also, buying centerless ground bars is much more cost effective for some shops since they are buying it ground to the finished part sizes. It is less expensive to centerless grind then it is buying a larger diameter and turning it down on a lathe or processing via other machines. It virtually eliminates outer diameter work and produces a finished part instead. In addition there is less variances than buying mill-run stock which typically holds tolerances of 2-3 thousandths on the ODs and less than that on roundness. With centerless grinding services, Alliant can hold tolerances of ten-thousandths of an inch on diameter. These tolerances produce bars with smooth, fine surface finishes.

Finally due to the critical condition of the surface finish and straightness Alliant packs and ships all centerless ground bars in special shipping materials to protect the surface during shipping. Bars are boxed or placed in cardboard tubes and covered in plastic mesh depending upon size and quantities.

We can provide bar to your exact specification from our extensive inventory. If your item is not in stock, let our sales staff source and provide the final product to your specification.