I want to add some lean muscle mass to my build, so im lifting heavy and for some reason when i do the bench press my muscles seem to give out to soon. This has always been my problem and its hard to increase my bench alot. For example ill do 10 reps with weight that just warms me up, and then do another 10 a little bit heavier. Then i'll do one or two sets of slightly higher weight about 3 or 4 times each. Then i finally add heavy weight and target at least 6 reps but many times i cannot get there.

Ive also tried doin 3 sets and i can do ten reps the first time and then the second time i will only make it to six with the same amount of weight. Its like ill lift it and i just cant seem to push it up any more. Does this sound like muscle failure or could it be that i have long arms and need to lower the weight? Any suggestions on a routine to increase my bench press? Thanks

That's totally normal and it's a good sign that you're using the right weight. If you can blow through ten reps in all three sets, then you're obviously not fatiguing the muscle which is the whole point. You'll know muscle failure when you feel it. When you're using every ounce of force to push the bar up and it's still coming back down, you've hit failure. You may be at or very close to actual muscle failure, but that really isn't especially relevant. As long as you're really pushing and really struggling, you're doing well.
One tip, you might start with the heaviest weights first after your warmup set. You should be able to get more overall reps out if you start heavier and work down to lighter as the muscle fatigues.