1. (a) Except as otherwise provided in this chapter, steps may be either rungs, treads or cleats, and shall have the dimensions specified in this section or be of equivalent strength.

2. (b) Wood rungs shall have the following minimum dimensions, length of rung to be measured between supports:

   Length of Rung (between side rails) (inches)	Center Diameter (inches)	Tenon Diameter (inches)	Tenon Length (inches)
   Up to and including 24	1-1/8	7/8	13/16
   Over 24, up to and including 32	1-3/16	7/8	13/16

3. (c) Oval wood rungs shall have at least the same strength and bearing as round rungs of the same length.
4. (d) Metal rungs of solid round steel stock shall have a minimum center diameter of 5/8 inch and tenon diameter of 1/2 inch.
5. (e) Metal rungs when made of pipe shall not be smaller than 1 inch standard steel pipe.
6. (f) Metal rungs when made of angle section shall have minimum dimensions of 3/4 by 3/4 by 1/8 inches.
7. (g) ‘‘U’’ sections shall, in general, be considered as the equivalent of a rung and shall meet all of the requirements of this chapter relating to rungs.

8. (h) Wood treads shall have the following minimum dimensions:

   Length of Treads (between side rails) (inches)	Thickness (inches)	Width (inches)
   Up to and including 16	25/32	3
   Over 16, up to and including 20	25/32	3-1/4
   Over 20, up to and including 24	25/32	3-1/2
   Over 24, up to and including 28	25/32	4
   Over 28, up to and including 32	1	4-1/2

9. (i) Metal treads shall have a width as specified for wood treads. In cross section metal treads shall be a channel or equivalent section equal in strength to the specifications for wood treads.

10. (j) Wood cleats shall have the following minimum dimensions:

    Length of Cleat (between side rails) (inches)	Thickness (inches)	Width (inches)
    Up to and including 20	25/32	3
    Over 20, up to and including 30	25/32	3-3/4

Cross References

This section cited in 34 Pa. Code § 21.23 (relating to wood steps); 34 Pa. Code § 21.34 (relating to fixed ladders); 34 Pa. Code § 21.35 (relating to single or straight ladders); 34 Pa. Code § 21.36 (relating to extension ladders); 34 Pa. Code § 21.38 (relating to trestle and extension trestle ladders); and 34 Pa. Code § 21.40 (relating to stepladders).