ASTM F735 - Abrading Medium
In June 2017, ASTM's Committee F07 on Aerospace and Aircraft approved the recommendation of updating the abrading medium referenced in ASTM F735 to a quartz silica sand, graded 6/9. The current version of this test method, ASTM F735-17 reflects this change.
December 2011, Taber Industries learned that the sole source provider of the 4/10 abradant described in section 6.1 of ASTM F735 was sold and the new company discontinued the product. The ASTM subcommittee responsible for this test method is working on initiating a round robin study to characterize / qualify a potential replacement material. The recommended material is a 6/9 Silica Abrasive Media which is available from Taber Industries. If you would like more information, please contact us.
The original abradant specified in ASTM F735 was Texan 6/12. Unfortunately, this product was obsoleted and not readily available to most test houses. Based on a grain analysis, replacement sand (Ogleby Norton 4/10) was identified and the method was updated. However in 2011, the sole source provider of the 4/10 abradant (Ogleby Norton) was sold and the new company (Carmeuse) discontinued the product. Because the sand was no longer available, a replacement abradant graded 6/9 was suggested.
A single lab study was performed in 2013 by Taber Industries to quantify results with the different sands. At the conclusion of this study, it was determined the cleaning method specified in the original F735 test method was insufficient and did not remove all sand residues. This was confirmed by another laboratory and in 2014, an improved cleaning method was established. An interlab study was conducted in 2015 with the objective of (1) quantifying the abrasion characteristics caused by four potential replacement sands on three different materials and (2) confirming the effectiveness of the proposed cleaning method. Measurements were collected for each of the four specimens. The averaged percentage of the transmitted light and percent haze for each specimen, both before and after exposure to abrasion of 100, 200, 300 and 600 strokes were reported. Using Minitab, a statistical analysis of the test results was performed along with a fully nested ANOVA analysis. This was to determine the significance factor of material substrate; test machine/location; and sand. Based on the results, the Carmeuse 6/9 was selected to be the replacement sand for the following reasons:
- Best consistency within test labs
- Values within acceptability to existing material
- Utilized the same mine as original sand
- Available off the shelf vs. custom blend