They’re actually one of your best defenses against ingrown hairs, apart from properly using pre-shave oil and beard growth oil, that is. Because these aren’t designed to get as close a shave as a safety razor paired with a shaving bowl and shaving soap, it leaves a little bit (sometimes 0.1mm to 0.5mm) of hair above the surface of your skin. Your hair can’t become ingrown if it’s already grown in.\r