Jean needle and thread and my 1950's Pinnock....big solid, heavy machine, will even sew leather and shadecloth. Not familiar with newer machines, but from the earlier replies, looks like they will handle the tough stuff too.

I will forward this information. Thanks for all your input.

I have a Singer 99k. I haven't tried it out yet but apparently it goes through leather with no issues. Singer also has an industrial machine you can get very cheap off Amazon.

I use an old Singer 201. It sews through anything and you can find them cheap.