Machine-Needle Know-How - Threads


Get Threads magazine!

Subscribe Renew Give a Gift

Machine-Needle Know-How

Key features of a standard needle
Forming a stitch
Key features of a standard needle

Key features of a standard needle

by Lydia Morgan
from Threads #94, pp. 59-61
 
Lay out an assortment of sewing-machine needles in various types and sizes on a table, and most of us can't tell the difference among them. But put the wrong needle in your machine, or use the wrong needle for your fabric and/or thread, and all heck breaks loose. You can damage your bobbin hook, throw off the machine's timing, get puckered seams, break or shred thread, punch holes in your fabric, and, at the very least, produce an inferior stitch. Whatever your machine, even the latest computerized model, needle selection can make or break your stitch.

At one time, only one type of machine needle was available to home sewers, and the sole choice involved was size. But today, home sewers can choose from a wide variety of needle types in their quest for trouble-free sewing.

Several things can determine the type of needle to pick: the fabric you're using; the thread you've chosen (for example, metallic or embroidery); or the type of stitch you plan (for instance, topstitching or hemstitching). When you're doing regular, not decorative, sewing, the type of fabric determines the shape of the needle's point, and the fabric's weight determines the needles' size.
 
But before deciding on a needle, you first need to know the needle system your machine uses. Unlike commercial machines, which use a variety of needle systems, almost all home-sewing machines use a 130/705H needle system -- designated on the needle case between the needle's name and size (other letters indicate needle type, such as M for Microtex or Q for quilting). Your machine's needle system never changes, regardless of the size or type of needle you use.

Tension control, stitch length, foot pressure, and other invisible settings on automatic machines are set for medium-weight fabrics, threads, and needles. If you're a middle-of-the-road sewer, using midweight, woven fabrics, you could be happy using a size 12 universal needle for the rest of your life. But when you want improved stitch quality, learn which specific needles to use for various jobs. See the box below to understand the build of this tiny, but important tool.
  
Anatomy of a needle

The key features of a standard machine needle are called out below. Their configuration varies from needle type to type.

Shank
Top of needle that inserts into machine; most often has round front and flat back, which seats needle in right position.

Shaft
Body of needle below shank. Shaft thickness determines needle size.

Front groove
Slit above needle eye, should be large enough to "cradle" thread for smooth stitches.

Point
Needle tip that penetrates fabric to pass thread to bobbin-hook and form stitch. Shape of point varies among needle types.

Scarf
Indentation at back of needle. A long scarf helps eliminate skipped stitches by allowing bobbin hook to loop thread more easily. A shorter scarf requires a more perfectly timed machine.

Eye
Hole in end of needle through which thread passes. Needle size and type determine size and shape of eye.
Anatomy of a needle

 
Select needle type by the task at hand
Sewing-machine manufacturers want their machines to consistently produce a perfect stitch. So the needle's configuration is engineered to manage thread and fabric to reduce the likelihood of skipped or flawed stitches. Each needle type produces a stitch by using a uniquely designed groove, scarf, eye, and/or point to enable the needle and bobbin hook to meet perfectly (see the box below). For a description of their uses, configuration, and how to troubleshoot them, see Sewing-Machine Needles: An Overview.

How a stitch is formed

The formation of a stitch begins when the needle penetrates the fabric and descends to its lowest point.

The bobbin hook then slides by the needle's scarf, catching the upper thread, and carries it around the bobbin and bobbin thread.

The thread is then pulled up into the fabric, completing the stitch.

How a stitch is formed



Choose regular needle size by fabric weight
When selecting a needle for regular sewing, start with needle size. European needles range in size from 60 to 120, which refers to the diameter taken on the shaft right above the eye. American needles are sized from 8 to 19 in an arbitrary numbering system, and paired with corresponding European sizes: for example, 60/8 or 70/10; the larger the number, the larger the needle.

Determine needle size by fabric weight. Choose a size 60/8 needle for lightweight fabrics similar to georgette or organdy; a 70/10 or 80/12 needle for medium-weight jersey, Lycra, linen, or calf leather; a 90/14 and 100/16 for heavy fabrics like jeans, vinyl, upholstery or canvas; and 110/18 or 120/19 for very heavy fabrics. After choosing needle size, match the needle point to your fabric. The needle type and name is usually determined by the characteristics of the needle's point.

Thread should pass easily through eye of needle
How smoothly the thread pulls though the needle's eye is also a factor in producing even, regular stitches. So if you have trouble threading the needle and problems with the stitches, the thread and needle aren't matched correctly. Lay your thread in the needle’s front groove; it should “snuggle” in.

In the end, most sewers just want to get professional-looking results. Knowing more about needles brings you closer to that goal, since needle choice greatly affects your outcome. For every correctly chosen, new needle you put into your machine, you should have eight to 12 continuous hours of trouble-free sewing.

Related article:
Sewing-Machine Needles: An Overview

Lydia Morgan owns a sewing business and Beacon’s Fabric and Notions (mail order), in South Pasadena, Florida.

Photos: Sloan Howard; drawings: Karen Meyer

Comments (5)

mbzaj mbzaj writes: Now I understand how the thread twists together inside. Finally! Thank you so much! (I was feeling like an idiot until now.)
Posted: 1:35 pm on February 6th

ExeterPops ExeterPops writes: Too wide printing problem is very common on dot com sites.

Problem is USA standard paper size larger than A4 which is commonly in use outside the USA.

To get to print correctly after click on 'print' look for 'properties' button and click on this. you will probably get a number of tabbed pages. On one of these pages you will find that there is a check mark against 'Print actual size'. Click on the check mark for scaling to A4 and you should be OK
Posted: 5:40 am on August 3rd

BrianSews BrianSews writes: Understanding how a stitch forms is the first step to getting perfect tension and stitches in any fabric!
Posted: 12:03 pm on January 26th

ChampagneDreams ChampagneDreams writes: Wow I never knew how that worked
Posted: 12:49 am on March 18th

louislampe louislampe writes: I canot print this article. Using your "print" feature it is too wide for the paper and loses the end of the line.
Posted: 11:48 am on November 27th

You must be logged in to post comments. Log in.