| 1/00 | Grates with solid bars (double grates F23H 5/00) |
| 1/02 | Grates with solid bars (double grates F23H 5/00) having provision for air supply or air preheating, e.g. air-supply or blast fittings which form part of the grate structure or serve as supports |
| 1/04 | Grates with solid bars (double grates F23H 5/00) having a variable burning surface |
| 1/06 | Grates with solid bars (double grates F23H 5/00) having bars at different levels |
| 1/08 | Grates with solid bars (double grates F23H 5/00) Vertical grates |
| 3/00 | Grates with hollow bars |
| 3/02 | Grates with hollow bars internally cooled |
| 3/04 | Grates with hollow bars externally cooled, e.g. with water, steam, or air |
| 5/00 | Double grates |
| 7/00 | Inclined grates (inclined travelling grates F23H 11/12) |
| 7/02 | Inclined grates (inclined travelling grates F23H 11/12) with fixed bars |
| 7/04 | Inclined grates (inclined travelling grates F23H 11/12) with fixed bars in parallel disposition |
| 7/06 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed parallel to direction of fuel feeding |
| 7/08 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed parallel to direction of fuel feeding reciprocating along their axes |
| 7/10 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed parallel to direction of fuel feeding rocking about their axes |
| 7/12 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed transversely to direction of fuel feeding |
| 7/14 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed transversely to direction of fuel feeding reciprocating along their axes |
| 7/16 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed transversely to direction of fuel feeding rocking about their axes |
| 7/18 | Inclined grates (inclined travelling grates F23H 11/12) with movable bars disposed transversely to direction of fuel feeding reciprocating in an upward direction |
| 9/00 | Revolving grates; Rocking grates (F23H 7/00 takes precedence) |