Although tin snips and aviation snips are alike and often used for the same jobs, there are some key differences between them.
Levers
Standard tin snips work like levers, with one blade pivoting against the other, in much the same way as scissors. When the handles are opened and closed, the blades cut through the material.For more information see: How do tin snips work?
Aviation snips have a compound action which gives them a mechanical advantage over standard tin snips. This is due to the double pivot and extra linkage in their design. This mechanical advantage means they should be more comfortable to use for longer periods than tin snips.For more information see: How do aviation snips work?
Price
Because standard tin snips are simple in design, they are usually cheaper, but are likely to last longer than most aviation snips. They are easy to use, but may be heavy, and will need to be large to match the force that aviation snips can produce.For more information see: How to use tin snips?
Applications
Aviation snips are more versatile and can be used for cutting more complex shapes, and thicker materials compared with tin snips of the same size.
Sizes
Aviation snips use their extra lever to exert more force, but tin snips rely more on the length of the tool and power of the user. Because of this, there is more variation in the size of tin snips, compared with aviation snips.