The graphic below illustrates the most desirable design for fabrications of handrail for galvanizing. It shows internal venting as well as the minimum amount of external vent holes.

1. External vent holes must be at least 3/8" (9.5 mm) in diameter and as close to the weld as possible.
2. For the best quality galvanizing and lowest cost, internal holes should be the full internal diameter (ID) of the pipe.
3. Vent holes must be 1/2" (13 mm) in diameter in end sections or in similar sections.
4. Ends should be left completely open. Any device used in the field that prevents full openings on ends of horizontal rails and vertical legs should be galvanized separately and attached after galvanizing.

This second graphic illustrates an acceptable alternative if full internal holes ( full ID of the pipe) are not incorporated into the design of the handrail.

1. Each external vent hole must be 25% of the pipe ID, but not less than 3/8" (10 mm) in diameter and as close to the welds as possible. The two holes at each end and at each intersection must be 180° apart and in the proper location as shown.
2. Vent holes must be 1/2" (13 mm) in diameter in end sections or in similar sections.
3. Ends should be left completely open. Any device used in the field that prevents full openings on ends of horizontal rails and vertical legs should be galvanized separately and attached after galvanizing.