It says heavy duty but it is not like my old Singer of 50 years ago. (Unfortunately, I gave it away a couple of years ago. Who would have thought I would want to start sewing face masks?). This one is all plastic. Even the bobbins are plastic. When I start sewing it does not feed well, especially on thick or doubled fabric. Hard to describe. Suffice it to say that this is a practical, useful machine, well worth the price. It's just not what I would call heavy duty.