I have a moderate woodworking background and get pretty moody about this topic so I will only list information.
There are 2 main types of inserts used in our application:
Soft wood inserts
Hard wood inserts
Our decks flex and move. No mater what material they are made of. For this reason, I recommend soft wood. Trampa/composite decks might be the only exception but I have yet to test one of those decks. The loose teeth grab more without stripping.
Hard wood inserts are for hard stationary wood like cabinets or other furniture.
To further confuse things, most of the hardwood inserts have slots in them. There is constant debate whether this is:
- for installation with a tool and the slots should be surface side
-Or-
- for cutting a thread (self tapping) and slots would be wood side
Both are correct! You need to know which one is which though.
You can differentiate these 2 by the depth of the slot and whether the slotted end is tapered like its meant to go in a hole.
Deeper slot and tapered edge = self tapping.
Shallow slot and square edge = insert with tool.
Some hard wood threaded inserts have self tapping barbs that will go on the bottom so I think that’s where a lot of confusion comes from (like drywall anchors). The slot on the thread is meant to be used with a specific manufacturer drill bit that will drive the insert without marring any surrounding wood. Most people just use a flathead screwdriver but make sure the head is NO WIDER than the insert itself. You can also use a hex head bolt that is meant to fit that specific thread pattern, tighten it into the insert, and then insert the insert/bolt combo into your hole and ratchet it tight.
Just a tip of general info that will serve anybody well: when picking a drill bit to fit a screw, the diameter of the drill bit should be equal to or barely smaller than the diameter of the screw’s shaft (if you stripped all the threads off)
As @Sender mentioned, epoxy the inserts in without getting any inside the insert