Age
Occasionally, a needle will break because the needle is old or defective. With regular use, the tip of the needle becomes dull and in some cases, the tip will break off completely. Needles also bend after some time. Change your needles on a regular basis according to the directions in your sewing machine manual.
Pins
Sewing over pins increases the risk of the needle breaking. It is best to avoid sewing over pins completely; however, if you are used to sewing this way, keep the pins perpendicular to the seam and keep heads of the pins far from the stitching line. Always be as careful as possible when sewing over pins.
Type of Needle
Some needles break because the needle you are using is not appropriate for the density and thickness of the fabric you are sewing. There are many needles available to fit the variety of materials used in sewing projects. Check your sewing machine manual for an indication of what types of needles work best with certain fabrics.
Needle Installation
Incorrect installation of the needle in the machine can result in a broken needle. Refer to your sewing machine manual and make sure the needle is in the proper position. Also, check your machine's presser foot, which is the part of the machine that holds the fabric during sewing. If the presser foot does not fit the machine or is incorrectly installed, this will also cause a broken needle.
Tension
Avoid pulling on the fabric while sewing. When you pull on the fabric, the tension causes the fabric to tighten under the needle, which often results in the needle bending and breaking. Gently feed the fabric under the machine's presser foot.
Thread Problems
Thread problems, such as too much tension on the thread or an incorrectly installed bobbin, can also cause needles to break. Check your tension settings and bobbin to troubleshoot a broken needle.