Vbelt Supply to start cracking from all the expans

Even the high-quality baked-on finish on modern iron hex dumbbells will eventually chip when the dumbbells are banged around a lot. Rubber dumbbells are made to be banged around. However, rubber exposed to the hot sun will expand as it heats, and repeated exposure can cause automotivedrivingbelt.com Vbelt Supply to start cracking from all the expansion and contraction, so if you're in a hot climate, it would be best to keep them out of the sun. Assuming you can manage that, rubber comes out ahead.

The plates on pro style dumbbells have a flatter finish that's more resistant to chipping than the finish on hex dumbbells. If you've ever dinged old hex dumbbells together at the top of a bench press rep and gotten paint flecks in your face, you know how significant this is. A rubber coating will of course prevent this, and non-rubber pro dumbbells can be assembled with rubber end caps.

Hex dumbbells are welded together, and while the welds are usually very good, the small risk of a bad weld here has to be acknowledged, particularly for dumbbells that don't go through the quality checking of one of the top US manufacturers. The way to break a dumbbell is to drop it from high up at an angle, so one head hits first and puts a lot of torque stress on the handle. When a weld fails the head won't usually come clear off, but it may become a little loose and wobble. The risk of this isn't really a safety issue, because it's pretty obvious when a head is just loose or if it has smashed around enough to actually fall off.

On pro-style dumbbells the plates are secured in place by an allen bolt that is quite tight from the factory. It's pretty obvious when it starts to come loose after a lot of usage, and it's a simple matter of tightening it.

#1: Rubber Pro Style

#3: Rubber Hex

#4: Pro Style

#5: Hex Automotive Belt Manufacturers