Guyson Corp.
Guyson Corp. surface roughness gauge, based on a third party-certified “Master Specimen” of non-periodic Ra standard.

Gauge Defines Ra Value for Non-Periodic Finishes in Blasting

March 28, 2023
A specific surface-roughness gauge for determining an exact Ra value based on a non-periodic value. is produced using a one-pass blasting method and quantified as per ASTM D7127.

GUYSON CORPORATION introduced a patent-pending surface roughness gauge, based on a third-party certified “Master Specimen” of non-periodic Ra standard. These specimens are produced using a one pass blasting method and are quantified as per ASTM D7127.

The “Guyson Institute of Standards” (GIS) was created to define the Ra finishing standards for non-periodic finishes for the blast finishing industry. Until now most roughness certified coupons were made to reference a periodic machine surface. A periodic surface is one that has a repeated pattern created by a machine cutting blade moving back and forth. Blast finishing is a nonperiodic process and its Ra value should not be determined with a periodic specimen which will give an inaccurate result.

Previously, a nonperiodic blast specimen did not exist, creating a problem when determining a precise roughness value on a profilometer. This added to the inconsistencies in results. The new GIS blast specimen determines a specific Ra value on a calibrated profilometer that will enable the user to correctly match that Ra Value on a product finish. All previous Ra measurements up to this point, are inconsistent because there was no scientifically certified specimen to determine the gloss value of a non-periodic finish.

Learn more at www.Guyson.com