At just over 3 inches in length, the AT-650 square-sided mixing tip is less wasteful than traditional 6 inch tips, but still long enough for thorough mixing of the adhesive components — even the more critical AT-6030 10:1 mixing ratio adhesive.
Note — Once you start using (gunning) the adhesive, the mixed product inside the tip will set in about 4 minutes if not used.
For jobs with long periods of time between applying the adhesive, you will either have to replace the tip, or after 4 minutes have passed gun the adhesive in the tip onto a piece of cardboard, replacing it with new adhesive to gain an additional 4 minutes of time - thus saving a mixing tip. (You can feel the difference in resistance when you have expelled the thickened adhesive.)
By either method you sacrifice an amount of adhesive equivalent to the volume of the mixing tip, so try to plan your project so the work keeps moving along.
Compared to traditional 6" mixing tips used by other manufacturers, the 3-1/4" AT-650 will save some expense in lost materials. The AT-650 tip has internal baffles and square corners - both create the swirling effect that thoroughly mixes the two adhesive components. Experimentation by Weld Mount engineers resulted in the shortest possible length that would get the job done.