The material your needle is made from matters. While the vast majority of hand sewing needles are made from nickel plated steel, there are other options. Here are the pro and cons.
Steel wire is cut to length and the eye is stamped into it. Because steel will rust, they plate the needle with another smooth shiny metal, most often Nickel. This works fine unless you have an allergy to nickel. Sometimes they plate it with titanium or gold.
SENCH needles have the eyes plated with gold to help identify which end has the point and which end has the eye. Gold plating on the eye also makes the hole more slippery to aid in inserting the thread.
No matter what, the plating will wear off and the exposed steel will rust. This will leave marks on your material. And makes the needle more likely to snap and break. If you tend to lose your needles and buy them every time you have a project to do, this is not important to you. If you are someone who just want to fix a hem or sew on a button, it is also probably not a problem
NOTE: In the olden days people would use the little strawberry thing hanging on the side of the tomato pincushion to knock the rust off and to sharpen the point. You cannot sharpen plated needles but you can sharpen stainless steel needles. Learn more about sharpening needles and the Tomato Pin cushion.
Stainless steel needles are hypoallergenic and will never rust. Because the stainless steel is the only metal, they can be sharpened without exposing them to potential rusting. They also tend to be stronger and not as brittle so they do not snap and break like nickel plated steel needles.
Spiral Eye Needles are made from Surgical Grade Stainless Steel.
more info needed here
Curved ones work well for apholtery projects. Leather needles have a tri-point designed to cut through leather.
details to add
They go by all sorts of names. Self threading, easy threading, side threading, Calyx eye, French spring eye, double eye, Spiral Eye, SENCH, and the One Second Needle. What is the difference?
The original side threading needle.
100% surgical stainless steel
Made in USA
Made in very small batches
in a wide variety of types of needles.
PONY Spiral Eye Needle on top
Pam's Original Spiral Eye Needle below.
Made in India
on dedicated equipment.
PONY is a leader in the world side needle industry.
Stamped eye is then cut to make the slot.
Limited sizes at this time.
(Spiral Eye Needles made in CHina)
Made in China
Mass produced on dedicatedequipment.
Limited sizes and types.
Does not have the "stop bump" inside fo the eye to save manufacturing costs.
It still stays threaded when you stitch. It just does not lock the thread inside.
Traditional eyes do not have an opening into the eye on the top or side. The eye gets smaller or larger with the gauge of the wire the needle is made from. The higher the number of wire the smaller the needle and the eye.
Needles used for embroidery have elongated eyes to make it easier to thread embroidery floss or other larger threads inside. The difference in the point is what changes the name of the needle. Tapestry means it has an embroidery eye and a blunt point. Chenille means it has the embroidery eye with a sharp point.
The top needle has a sharp point.
The bottom needle has a Blunt (or Tapestry) point.
Sharp points are use to pierce into the material and it may or may not pierce through a singe thread in the cloth.
Tapestry needle points are made to NOT pierce the threads of the material. For instance in cross stitch, the material, called Aida, has very defined squares you want to get the point through.