Working in a fabric shop I often get asked which needle to use in people's machines....that ....and which thread but that is a whole story! Many have never changed the needle in their machines and had no clue there were different types or sizes!
Most sewing machine needles will fit on almost all your standard sewing machines. I say most as some of the old machines need special needles and I'm sure someone out there has a machine that just doesn't fit in here. Most packages have both metric and American sizing on them and may appear as 80/12 or 110/18. The smaller number is the American sizing system and the other is the metric number related to the size of the shaft. The larger the number, the bigger the shaft diameter. You should use the proper size needle for the fabric you are sewing on and the weight of the the thread you are using.
Many packages sold will tell you what type of fabric they are made to sew on. Sewing experts differ on actually how often a needle should be changed. Many people don't change theirs unless it breaks! Recommendations range from every 8-10 hours of sewing time to changing with each new project. However often you decide if you experience any stitching problems, always check your needle. A dull or burred needle can cause fabric snags or puckers.
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