There were not too many bolt sizes for me to choose from, I choose a larger size (most others were quite small and would likely not support my weight). They did not come with weight ratings, so just use common sense, and if in doubt, go bigger.
|Note the size of the drill bit vs bolt|
The packet suggested a 5mm drill bit to drill the pilot holes, however I only had 6mm or larger. Compare the size of the drill bit to the size of the central part of the bolt, not the thread of the screw. Ideally the drill bit should be no bigger than this central part of the bolt. Any larger and the thread may not have enough material to bite into when screwed in.
I placed the bolts 500mm apart as this is the standard distance between Olympic rings. I measured and marked the centre of the overhead rafters and drilled a pilot hole the same length as the bolt. I used a large screwdriver as leverage to screw the bolt in. If this is too difficult I am told using a small amount of soap on thread will make it easier to screw in. I screw the bolt in approximately 10mm deeper than the thread. This is just preference once the thread is screwed in.
These anchor points are excellent for hanging rings, and any number of grip training implements. They are cheap and easy to set up, and it helps to have something to hang from indoors when it’s raining.