The Anchor nut and washer inserts mounting system is the strongest in our industry. A single insert will stand a direct pull of over a ton without the support of the steel disc wheel.
The length of disc mounting screws is critical. The screws should project through the steel disc wheel more than 3/8" so that enough threads are engaged with the inserted nut. The screws should not project more than 7/16" as there is a possibility of bottoming in the insert.
Screws that are too short will not have the proper holding power. Screws that are too long will hit bottom and jackscrew the insert out of the abrasive, and/or crack the disc.