The needle size used by Jeans Sewing Machine is usually determined according to the thickness of the fabric and the size of the needle eye. Different needle sizes are suitable for denim fabrics of different thicknesses.
Under normal circumstances, the needle size used by the jeans sewing machine is 14-18. Among them, the 14-gauge needle is suitable for lighter denim fabrics, while the 18-gauge needle is suitable for heavier denim fabrics.

It should be noted that the needle size is only a standard size of the needle, and the appropriate needle type should be selected according to the characteristics, thickness, texture and other factors of the fabric. Also, different brands of sewing machine needles may have different standard sizes, so it is advisable to test a new needle before using it.
When sewing jeans, it is recommended to use special denim needles because their eyelets are larger than normal needles, making it easier to get through the thick fibers of denim. Also, denim needles have a sharper tip than regular needles, making it easier to pierce denim.
In short, choosing the appropriate needle size is the key to sewing jeans. Factors such as fabric thickness and texture should be considered when choosing a needle size to ensure the quality and aesthetics of your sewn jeans.
Also, in addition to needle size, there are a few things to keep in mind when sewing jeans:
Use the right thread: Denim is heavy and heavy and requires a stronger thread,