If your arms are slow to grow, try these routines that incorporate a couple of techniques normally reserved for larger muscle groups: lockouts and pre-exhaust training.
With lockouts, you work over only the top third of the range of motion (ROM). After you complete three sets of full-range close-grip bench presses (hands shoulder-width apart), do partial reps with a weight that’s 10%-20% more than your one-rep max. Use a power rack with the safeties set about 4 inches below the point at which your arms are fully extended, or you may be able to use a Smith machine with the stops similarly set. Do one last back-off set in which you remove the extra 10%-20% and do as many reps as you can.
The pre-exhaust routine flip-flops the single-joint and multijoint exercises: Whereas you typically might do a triceps movement in which you’re strongest and can lift the most weight first in your workout, now you’ll do it last. Multijoint exercises allow secondary muscle groups to kick in; in this case, the pecs and front delts help you push out more reps as your tri’s get toasted.
For both workouts, choose your weights to approach muscle faulure by the rep listed.
