Setting Standards: Part 2

The year 2016 marks a special anniversary for our company: 100 years since the creation of the first ever safety code for abrasives. Throughout the year we will be featuring a series of articles to celebrate this pioneering achievement made possible only through the former Norton Company’s leadership in the field of abrasives safety.

PART TWO

Part One of this series traced the roots of the abrasives safety code back to its origin 100 years ago. The seeds of this groundbreaking work were sown by the former Norton Company, known today as Saint-Gobain Abrasives, whose technical innovations and staunch leadership brought it to reality. A century later, the three pillars of the original safety code—Guards, Flanges and Speeds—remain in place as fundamental elements of abrasive wheel safety. 

Having discussed Guards in the first article, including their introduction at a time when such protective devices were scarce, and their evolution over the last century, attention is now turned to the second pillar: Flanges.  

Flanges are the equipment used to attach (or “mount”) a grinding wheel to the rotating shaft of a grinding machine. Just as a car tire needs a wheel in order to be attached to the axle, so a grinding wheel needs a flange. But not just any will do; properly designed and maintained mounting flanges are essential to operator safety. 

The authors of the 1916 standard recognized the connection between flange problems and operator injuries, and they responded with the first published guidelines for design and maintenance of abrasive wheel mounting equipment. Their original guidelines were so effective that most are still followed a century later, as seen in the ‘then and now’ pictures on the right. 

Figure 1 is a mounting diagram reproduced from a 1909 Norton Company publication (seven years before the Safety Code was published) explaining several key points for safe mounting: 

• Both flanges must be of the same diameter.
• Flanges must have bearing surface near the outer edge and clearance at the center.
• Inner flanges must be locked (keyed) onto the spindle. 
• A blotter (washer) must be placed between flange and grinding wheel. 
• Spindles must be long enough to engage all threads of the end-nut. 

Remarkably, every one of these points is preserved in Figure 2, which is the mounting diagram from the 2010 safety standard. [1]  So, despite a century of progress in science and technology, most of the original Norton Company guidelines for flanges remain valid, standing as a testament to their effectiveness. 

While many original parameters have stood the test of time, others have not. One interesting example is the beveled flange design shown in Figure 3 that was once believed to offer greater protection in the event of wheel breakage. In theory, upon breaking, the wedge-shaped grinding wheel fragments would be held inside the flanges, whereas a straight-sided wheel could escape more easily. But this design was eventually abandoned partly because, in practice, some outer fragments not enclosed by the flanges were still able to escape and cause damage. 

As one would expect of a century-old industrial standard, not every branch of the original tree survives today. But as has been shown, an exceptional amount of the original abrasives safety code remains intact, especially in the area of mounting flanges. These lasting principles have helped the industry to reach new heights in abrasives technology while keeping roots safely planted in sure ground. 

[1] ANSI B7.1-2010, Safety Requirements for Use, Care and Protection of Abrasive Wheels

For additional information on this topic or if you need any other abrasives safety information, please review  ANSI, OSHA and all literature provided by the abrasive and machine manufacturer. You may contact the Saint-Gobain Abrasives Product Safety Department at (508) 795-2317, Fax (508) 795-5120 or contact your Saint-Gobain Abrasives representative.