Roton builds hinges in three basic application ranges:

780 Series:
All 780 Series Roton hinges are manufactured with thrust bearings spaced along the hinge length on 5-1/8" centers. A typical 780 Series 83" Roton hinge carries the door weight on SIXTEEN bearings. The joining channel (which carries the lateral load), the bearing spacings and screw fastener locations are designed for much heavier loads than hinges in the 750 Series. 780 Series hinges are recommended for use with doors up to 200 lbs. For any hollow metal work, moderate frequency entrances or high frequency solid core or laminate doors, etc., use 780 Series hinges.

780HD Series:
All 780 "HD" Series Roton hinges are manufactured with thrust bearings spaced along the hinge length on 2-9/16" centers. A typical "HD" Series 83" Roton hinge carries the door weight on THIRTY-TWO bearings. These hinges are supplied with staggered screw holes to suit heavy-duty applications OR high cycling conditions such as high traffic entranceways, public lavatories, etc. Where other hinge hardware has repeatedly failed, the "HD" is the best possible choice at a modest premium over the standard 780 Series. These hinges are suffixed "HD" for Heavy Duty.

780LL Series:
All 780 "LL" Series Roton hinges are manufactured with thrust bearings spaced along the hinge length on 2-9/16" centers, as in the 750 "HD" Series, except that the screw holes are closely placed in a double row on each leaf for very heavy door aplications such as lead-lined X-ray doors, sound studio doors and heavy security doors. These hinges are listed with the suffix "LL" (Lead-Line), and have been used very successfully with door weights of over 1,000 lbs. For doors of lower weight where cycling conditions are very high, the HD Series is preferable to save the installation time of a few extra screws on each door.

Fire Rated Hinges:
780-112
780-112HD
780-112LL
780-224
780-224H
780-224LL have the Warnock Hersey listing for approved use in the following applications:
20 Minute Fire Rated Wood or Steel Doors and Steel Frame Mounted in Drywall.
And:
45 Minute Fire Rated Wood or Steel Doors and Steel Frame Mounted in Masonry Wall;
90 Minute Fire Rated Steel Doors and Steel Frame Mounted in Masonry Wall (Door hinge edge and frame must be minumum 16 guage steel.)

Maximum Size of Openings:
Single doors 4'0 X 9'0
Double Doors 8'0 X 9'0