You can try a heavy duty needle, but there's a pretty good chance a domestic sewing machine just won't work with seatbelt webbing. I'd recommend caution
Sewing, Repairing and Reducing Waste
A place to share ideas, knowledge and creations with textiles. The focus is on reducing waste, whether that be sewing from the scraps left from other projects, using the end of rolls and remnants, or repairing and remaking finished pieces.
Thanks! Serious question: what's the worst that could happen?
Wear glasses/eye protection.
I have pushed past the point of common sense with my machine before and snapped needles. They go flying.
Snapped needles are the most likely thing that could happen.
Sometimes people assist the motor by turning the hand wheel, and I've heard that can bend the frame of the sewing machine in some cases. That'd be the most catastrophic failure potential I think
Likely not much, really. Try going slowly at first, and speed up if it goes well.
I’ve used a regular machine with a denim needle to sew a couple nylon webbing layers together. I don’t know how sturdy you need the thread to be but general utility thread should work for a basic bag, or you could get a spool of Gudermann(?) thread for a step up.
It should be fine, seat-belts aren't that thick. I'd use size 69 bonded nylon or polyester thread.
Okay :) what type of needle would you recommend? Someone else recommended a denim needle