There are two primary reasons and a few secondary reasons why folks choose 23 gauge pins for an application.

1. Quality of Finished Product

The 23 gauge pin leaves a considerably smaller hole than an 18 gauge brad, making its entry point much less noticeable. This is due to the smaller diameter of 23 gauge ( .025") vs about .080" for the head of a typical 18 gauge brad, while having sufficient strength for many of the jobs historically done with brads. Because the hole is so much smaller, it can be filled by sanding with 200 grit paper and pushing the sanding dust into the hole. The dust is exactly the same color as the surrounding wood and will be after years of UV exposure. When you fill an 18 gauge brad hole with filler, the glue in the filler will change color differently than the surrounding wood and will become increasingly noticeable with time. And, while the filler used in an 18 gauge brad hole will continue to shrink over years, leaving dimples in your finished work, the dry sanding dust you pushed into the 23 gauge hole will not. If it is true that the better your work, the closer others will want to inspect it, then 23 gauge is the hands-down winner.

2. Time Spent

Because the 23 gauge hole is much smaller than that left by an 18 gauge brad, it does not have to be filled if the workpiece is going to be painted. The paint solids will fill the very small hole. If a transparent finish will be applied, there is no need for putty and sanding. Simply sand and fill the hole with sanding dust. On much prefinished work such as trim, no filling is necessary as the small hole disappears in the grain of the wood. While an 18 gauge brad is no substitute for clamps when doing light assembly, the 23 gauge pin is the perfect solution.

3. No Edge Splitting

Due to the small diameter of a 23 gauge pin, it displaces very little material when it enters a workpiece. Therefore, it can be used in materials like MDF and very close to the end or side grain of hardwoods without causing blowout or spitting. With a little experience, you can place a 23 gauge pin as close as 1/32" from the edge of an oak workpiece without edge splitting.

4. Amazing Strength

Two pieces of 3/4" x 1 1/2" oak, about 5" long cannot be pulled apart when held together by 2 2" long 23 Gauge pins. The holding power of the 23 gauge pin does not come from having a head but rather from angling or toeing alternating shots towards one another. The result is that, when one attempts to pull fastened wood apart, the pieces want to slide in 2 directions at the same time.

5. Cut-ability

The fine 23 gauge pin will be easily cut on the table saw or compound miter saw with no damage to the blade.

6. Less Blow-out in Hardwoods than with 18 Gauge

No-one likes it when during final assembly, a brad follows the grain in a piece of oak and blows out the side. It takes time and fiddling to deal with that and one seldom gets a satisfactory result. The 23 gauge pin has a smaller diameter than the 18 gauge brad and is more likely to break through the grain rather than following it. As well, it is possible on best 23 gauge pinners (like Grex) to raise the operating pressure to 140psi or so to achieve faster muzzle velocities and an improved likelyhood of breaking through the grain. Lastly, high tensile strength pins (Grex are the hardest) are stiffer and less likely to bend with the grain. Of course, if you still get blowout, it is a simple and easy thing to wiggle the pin, the result of which is that it will usually break off... below the surface.

7. Range of Applications

The 23 gauge pin can be used in many applications where a brad nail is not suitable such as:

Blind Nailing A flap is cut in the surface of hardwood with a fine gouge. The workpiece is pinned under the flap which is then glued back into place making the fastener impossible to find

Cross-Pinning box joints, dowels, locked miter joints is fast and almost imperceptible. A belt and braces approach.