Common Terms Used Around Precision Rolls
We provide the following definitions in the hope that they may be helpful in explaining words, terms, and processes used within the text of our web site. Please contact us if you need further clarification or require additional information about these particular words or about any aspect of Roll Technology services or procedures.
Chromium Plated and Belt Polished
Roll to be received ready to plate with a fine ground, defect free finish. Roll Technology would belt polish, hard chromium plate, and belt polish the roll face. No precision grinding is involved.
Cylindrical Roll Grinding
Cylindrical, precision roll grinding involves supporting the roll, shaft, or drum either between machined centers or directly on the roll's bearing surfaces. The outside diameter of the roll is then precision ground using appropriate grinding wheels. Critical to the roll grinding operation is basic knowledge such as the construction of the roll, wall thickness, deflection characteristics, and the base metal material.
Decorative Chrome Plating
Decorative chrome plating such as that used on furniture, motorcycles, hubcaps, etc. is a completely different process from hard chromium plating. It involves electroplating a thin layer of chromium onto a metal object. Roll Technology does not do decorative plating.
Fine Precision Ground and Belt Polished Finish
Roll to be precision ground after chromium plating to a fine ground finish and then belt polished smooth.
Fine Precision Ground Finish
Roll to be precision ground after chromium plating and shipped with a fine ground (not polished) finish. Typical of high precision coating rolls.
Finish Grinding in Precision Bearings
When it is necessary to produce an industrial roll that has the lowest possible operating T.I.R. (precision roll coating, precision calendering, etc.), it is possible to cylindrically grind the roll with its precision bearings in place on the journals.
When a roll is ground in its bearings, the resulting T.I.R. is typically lower than the specified accuracy of the bearings. Finishing in bearings also significantly simplifies the installation of the roll into a production line. The cost of finishing in bearings is usually offset by the savings in installation costs.
Finishing in bearings creates a dedicated assembly of the roll, bearings, seals, housing caps, locknuts, and other related hardware. All items mounted on the journals located between the bearings need to be supplied by the customer for mounting in place by Roll Technology technicians.
Hard chromium plating, as the name implies, is extremely hard (68-70 Rc as deposited) and, as such, is suitable for a wide variety of industrial applications that require resistance to wear. It is also the finest metal deposition to utilize when specifications call for very low smoothness characteristics on the roll face.
Hard chromium plated rolls must be precision ground after plating to obtain exacting tolerances for accuracy and surface finish.