Spring needles: This needle has a wire spring above the point to prevent fabrics from riding up onto the needle when the presser foot is removed and the feed dogs are dropped for free-motion stitching. Spring needles can be purchased in universal, stretch, denim, embroidery and quilting types.
Twin and Triple Needles: Two or three needles are put on a single crossbar. They can be found in denim, stretch or embroidery type needles. Their purpose is to create perfectly parallel, multiple rows of stitching in one pass using a single bobbin thread.
Spacing between the needles varies from 1.6mm to 8mm wide. They are numbered first by the distance in millimeters between the needles and second by the size of the needle. Generally the finer the fabric the more closely spaced the needles should be.
Use these needles with an oblong throat-plate opening such as those found on every zig-zag machine.
Wing Needles: Fins on the sides of the shank create large holes in tightly woven fabrics such as linen and batiste. Hemstitch is another name used for this needle. It is used for hemstitching, heirloom embroidery and other decorative techniques.
Wing needles are available as singles or as twins that have a wing needle and a standard needle on a single crossbar.