New Hudson Corporation introduced the Metal Donut™ Roller in 1986 in response to the industry’s interest in having only metal rollers in the annealing lehr. Many hundreds of Metal Donut™ Rollers are now operating successfully in float glass lines worldwide.

Metal Donut™ rollers are typically installed in the C and cooler zones of the lehr - Cnud: C, D, RET and E zones and Stein Heurtey: C and D zones.

In the rapid cooling zones of the lehr, the ambient temperature of the lehr and roller is significantly less than the glass ribbon. Hot glass touching a cool roller can develop transient temperature variation in the roller. Temperature variations within the steel roller will cause roller eccentricity, which in turn can cause marks on the glass ribbon. The Metal Donut™ Roller solves this problem and provides a dimensionally stable stainless steel roller for the cold end of the lehr.