I have noticed that the dumbbells i use at home make my joints pop even though they have the same weight as the dumbbell i use at gym but different shape,the dumbbells i use at gym have the same weight none of them make my joints pop, what causes this?
This is kind of vague, but my first thought would be that even if they show the same weight, they are not the same weight.
When weights are made they are made with a tolerance, usually the more expensive brands are +- 1% whereas the cheaper ones can go up to +- 10%> this may not seem like a lot but dumbbells have weights on both sides.. picture a 100 lb dumbbell. 50 lb on each side, one side could have -10% while the other has +10% making one side 45 and the other 55 and it could seem off balanced. Or each side could have a +10% making it 110 lb dumbbell in one hand and 100 in the other.
I would assume your gym, whether they are expensive or not, has dumbbells you use more often and are used to. Then when you're home and use yours which could weigh more, or even not weigh correctly. CAP is known for having big weight tolerances. Even if your weights are a pounds heavier at home it's still more than your used to.
Some dumbbells also have wider grips. This could be the issue too.
Otherwise if it's not this, then it could be something else as this really isn't a common problem. Your joints should never pop, so either the weights too heavy or you need to go to a physical therapist to get evaluated.