Sawbacks go back even further. Germany isued a sawbacked bayonet in WW1. To expand on crosscut saws, they actually have cutting teeth and rakers. the teeth cut the wood fiber much as a knife. The rakers then actually chisel and remove wood shavings. A close examination of SAK,Opinel and similar accessory saws will show an ingenious tooth that combines both in one direction. My old AF Camillus worked well on rendering aluminum also.