What do you use a 18 gauge brad nailer for?
Also question is, can you use 18 gauge nails for baseboards?
Both are commonly used for installing baseboard, chair rail, door and window casing, crown molding, and door frames. One advantage to 15-gauge nails is that they are collated at an angle, which allows the nose of the nailer to reach into tighter spaces. Brad nailers use smaller 18-gauge nails up to 2 inches long.
Also asked, should I get a 16 or 18 gauge nailer?
“16 gauge is the most versatile type of nail to use. It can penetrate and support thick boards and hold them in position permanently. You should only get a 18-gauge brad nailer, if you're willing to attach trim molding and other delicate trim pieces.” An 18-gauge fastener is smaller than 16-gauge fastener.
For trim purposes you should be looking at using 15-, 16-, 18-, or 23- gauge nails. Brad nails are thinner in cross section allowing them to leave a smaller, neater hole which can be filled up and smoothed down easily. This makes brad nails the perfect choice for all your trim applications.