Choosing the Right Needle

Choosing the Right Needle

Needle Basics: Domestic sewing machines today basically use the one needle system (705/130H, HAX1, 15X1) but they are available in a large variety of sizes and point styles. Selecting the right needle and thread for the fabric you plan to sew is one of the most fundamental steps to achieving a successful stitching result.
Machine Needles come in sizes ranging from sizes Metric Size 60 to 120 (Imperial Sizes 8 to 20). This size essentially represents the thickness of the needle. The lower the number, the finer the needle. Thread, however, is the opposite, the finer the thread, the higher the number.
When sewing, the thread lies in the needle groove, if the needle is too fine for the thread, the thread will not fit into this groove causing faulty stitching.
The needle must also be in perfect condition. Stitching problems occur from using a needle that is either blunt, bent or if the tip has been damaged.
 
Size is Important: In general the sewing thread diameter should be about 40% of the needle size (Nm). The reason for this is the ratio of the needle size to the cross-section of the long groove.
The long groove down the front of the needle plays a critical role in the formation of each stitch. The width of this groove is 40% of the needle diameter, i.e. in a size 100/16 needle ( which is 1.00mm thick ) the groove size is 0.40mm. The thread must fit nicely into this groove, and if the thread is too thick as shown in this first drawing, the thread can jam and all types of stitching problems will occur: such as thread stripping, thread breaking, missed stitches ,uneven tension etc.
When the thread size fits neatly into the long groove, this creates the optimum conditions for the best stitch, the best tension and hassle free stitching.
When the thread is much thinner than the groove, this creates a situation where an excessive amount of thread can form in the groove, which in turn may reduce the size of the loop and skipped stitches, uneven tensioning etc can result.

Why Needles Break: The reason needles break is that the needle is operating within very fine clearance of the sewing machine hook mechanism, and this expensive and critical part of the sewing machine must be protected from damage. If the Hook (which catches the needle thread and carries it around the bobbin to form the lock stitch) is scratched or damaged by the needle, this could result in stitching and tension problems and ultimately an expensive repair bill for your machine. If during the stitching process, the needle is deflected more than 15 degrees, or if it is bent and remains bent it is likely that damage to important parts of the sewing machine will result.
So good quality sewing machine needles are designed to break when something is wrong, so as to protect the expensive mechanism of the machine. When a needle breaks regularly, look for the cause - don’t blame the needle Reasons that sewing machine needles break:
- Needle is too fine for fabric.
- Stitching over pins or zippers.
- Wrong needle system for machine model.
- Upper tension is too tight.
- Bobbin case or bobbin incorrectly fitted.
- Presser foot is loose and not properly fitted.
- Needle not properly set or is loose.
- Fabric is too thick and does not match needle in use.
- Pulling fabric without raising the presser foot after sewing.


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