Flagpoles are metal piping with thick enough walls (generally 1/4 inch thick or more) designed to withstand the wind load a flag exerts on the pole during high-wind weather conditions. Galvanised pipe is well-suited to such an application due to its resistance to the formation of rust, which could weaken the metal. Due to this resistance to rust, such pipe can be used as a permanent mast for flying a flag, where untreated steel pipe must be removed periodically and replaced with new pipe to replace a rusty, corroded section.
Lay the galvanised pipe on the ground. Measure 1 foot from one end of the pipe (the top) and mark where the hole is to be drilled to secure the top bolt-on pulley assembly. In like manner, measure 5 feet from the other end and mark where the hole is to be drilled to secure the bottom bolt-on pulley assembly. Make sure the bolt-hole markings on the top and the bottom are lined up as perfectly as possible.
Select a suitable drill bit for the size of bolts which came with the pulley assemblies and drill the top and bottom holes in the pipe. Drill through one side of the pipe wall and continue drilling until the bit exits through the outside of the other wall of the pipe.
Bolt the pulleys onto the pipe with an appropriate wrench set, placing a lock washer and nut on each. Tighten until hand-tight, then tighten further until the nuts cannot be turned any more. Use caution so the bolts aren't stripped while tightening.
Thread rope through the pulleys and tie a knot in the rope just above the lower pulley. Connect a flag clip to the rope at this knot, then measure the correct distance to the position of the other flag clip hole on the flag and install another into position on the rope (measure the distance of the holes in the flag itself for accurate positioning of the clips for your particular flag).
Dig a square hole where the mast is to be set, 4 feet deep and 2 feet wide. Set 4 feet of the 5-foot end into the hole and have a partner assist by holding the pipe in place, as straight as possible.
Drive four 4-foot sections of copper grounding rod into the ground about 1 foot out from each corner of the square hole, driving them at a 45-degree angle so the rods are aiming away from the pipe.
Tie pieces of rope to each of the rods and also to the galvanised pipe so the ropes are holding the pipe vertically into place. This will prevent the pipe from leaning while the concrete slab dries after pouring. Check the pipe with a carpenter's level by pressing the edge against the side of the pipe on all sides. Adjust the pipe until the bubble in the level is between the centre marks on the observation glass cylinder, then tighten the ropes to hold the pipe to prevent movement.
Fill the hole with concrete until level with the ground. Smooth the top and allow to cure for several days to a week before removing the securing ropes and rods.
Never install a metal flag pole near power lines or in an area where it may be struck by vehicles. Severe injury or fatality may result if adequate clearance isn't provided.