Use a size 16/100 or 18/110 needle for most denim work

A size 16/100 needle is the standard choice for medium-weight denim like jeans and jackets. A size 18/110 needle works better for heavy denim, canvas, or multiple layers. The larger the number, the thicker the needle shaft — denim requires a needle sturdy enough not to bend or break under the pressure of pushing through dense fabric.

Size 14/90 needles are too thin for denim and will bend or snap. Size 12/80 and smaller are designed for lightweight cotton and silk, not for the tight weave of denim. If you are sewing a single layer of lightweight chambray or shirting denim, a 14/90 may work, but most denim projects demand 16/100 as a minimum.

The needle size you choose also depends on your thread weight. Thicker thread (like topstitching thread) needs a larger needle eye to pass through without fraying or shredding. If you are using standard all-purpose thread on medium denim, size 16/100 is sufficient. If you are topstitching with heavy thread, move up to 18/110.

Key Takeaways

  • Size 16/100 needles work for most denim projects, including jeans, shirts, and light jackets.
  • Size 18/110 needles are necessary for heavy denim, multiple layers, or topstitching with thick thread.
  • Never use needles smaller than 14/90 on denim; they will bend or break under the fabric's density.
  • Change your needle after every project or every 8 to 10 hours of sewing, because denim dulls needles faster than lighter fabrics.
  • A bent or blunt needle will skip stitches, pull threads, and damage the denim; replace it when ready if you notice these problems.

Why needle size matters for denim

Denim is tightly woven and resists the needle's passage more than cotton lawn or quilting cotton. A needle that is too thin will flex under this resistance, causing it to miss the fabric or bend permanently. A bent needle cannot penetrate straight, so it skips stitches or creates uneven tension.

The needle shaft also carries the thread down into the fabric. A thin needle has a small eye and a narrow groove along its shaft, which cannot accommodate thick thread or hold it steady as it passes through dense fabric. Topstitching thread, buttonhole thread, and heavy-duty thread all need a larger needle to prevent shredding and thread breakage.

Denim also dulls needles faster than lighter fabrics because the needle strikes more fiber per stitch. A needle that works fine on cotton may become dull after a few hours on denim, leading to skipped stitches and pulled threads. This is why many sewers change needles more frequently when working with denim than with other projects.

Needle type: universal versus denim-specific

Universal needles in size 16/100 or 18/110 work for most denim sewing. They have a slightly rounded point that penetrates woven fabric without damage and work with standard polyester or cotton thread. Universal needles are the most common type and are sold in every fabric store.

Denim needles are a specialized option with a reinforced shaft and a slightly modified point. They are designed to withstand the repeated impact of pushing through dense fabric without bending. If you sew denim regularly, denim needles last longer and produce more consistent stitches than universal needles of the same size.

For occasional denim projects, a universal 16/100 or 18/110 is sufficient and less expensive. For frequent denim sewing, denim needles in the same sizes are worth the small extra cost because they reduce needle breakage and skipped stitches. Both types are available from fabric stores and online retailers.

Adjusting needle size for layers and weight

A single layer of standard jeans-weight denim requires a 16/100 needle. Two layers (such as a hem or a seam allowance) may still work with 16/100, but three or more layers — or heavy raw denim — call for an 18/110 needle. The thicker the combined fabric, the more force the needle must withstand.

If you are sewing through a seam allowance that crosses another seam (a common situation at pant inseams), you may have four or five layers of denim at once. In this case, an 18/110 needle is safer. Some sewers move up to a 20/120 needle for extremely heavy denim or multiple-layer situations, though 20/120 is less common and may require special ordering.

Test your needle choice on a scrap of the actual denim you plan to use. Sew a few stitches through the layers you will encounter in your project. If the needle bends, skips stitches, or feels like it is struggling, move up one size. If the stitches are even and the needle moves smoothly, your choice is correct.

Thread choice and needle pairing

Standard all-purpose polyester or cotton thread works with a size 16/100 needle on medium denim. If you are topstitching with heavy topstitching thread, buttonhole thread, or thick decorative thread, you need a larger needle eye to accommodate the thread diameter. A size 18/110 or 20/120 needle is necessary for these threads to pass through without fraying.

Topstitching thread is thicker than standard thread and is often used on jeans for visible seams and hems. Buttonhole thread is twisted and heavy, designed for strength. Both require a needle with a larger eye and a wider groove. Using standard thread with a 16/100 needle on these heavy threads will cause the thread to shred or break as it passes through the needle.

If you are unsure whether your thread is heavy enough to require a larger needle, hold the thread next to a standard all-purpose thread. If it is visibly thicker, use a 18/110 or 20/120 needle. The needle package will often note which thread weights it is designed for, so check the label before you buy.

Signs your needle is wrong or worn out

Skipped stitches are the most common sign of a needle problem. If your machine is skipping stitches on denim even though you have threaded correctly and the tension is set properly, the needle is either too small for the fabric or too dull to penetrate cleanly. Replace it with a fresh needle one size larger.

Pulled or shredded thread is another indicator. If the thread is fraying as it comes out of the needle, or if you see loops of thread pulled from the fabric surface, the needle eye is too small for your thread, or the needle is bent. A bent needle will also produce uneven stitches or a loud clicking sound as it hits the needle plate.

Denim dulls needles quickly, so replace your needle after every project, even if you have only sewn for a few hours. A fresh needle costs less than a dollar and prevents hours of frustration. Keep a supply of size 16/100 and 18/110 needles on hand so you always have the right size ready.

Frequently Asked Questions

Can I use a size 14/90 needle on lightweight denim?

A 14/90 needle may work on very thin denim like chambray or shirting denim, but it risks bending under the fabric's resistance. A 16/100 is safer and only slightly more expensive. If you are sewing lightweight denim, test a 14/90 on a scrap first; if the needle bends or skips stitches, switch to 16/100.

What needle do I use for topstitching jeans?

Use a size 18/110 needle with topstitching thread, which is thicker than standard thread. The larger needle accommodates the thick thread and penetrates the denim more reliably. If you are topstitching with standard thread, a 16/100 needle is sufficient, but 18/110 is still a good choice for the extra durability.

Do I need a special denim needle or will universal work?

Universal needles in size 16/100 or 18/110 work fine for denim. Denim-specific needles have a reinforced shaft and last longer, but they cost slightly more. For occasional projects, universal needles are sufficient; for frequent denim sewing, denim needles reduce breakage and skipped stitches.

How often should I change my needle when sewing denim?

Change your needle after every project or every 8 to 10 hours of sewing denim. Denim dulls needles faster than lighter fabrics because the tight weave creates more friction. A dull needle will skip stitches and pull threads, so replacing it regularly prevents these problems and keeps your stitches even.

What size needle do I need for hemming jeans?

A size 16/100 needle works for a standard jeans hem, which is usually two or three layers of denim. If your hem is thicker or you are sewing through an existing seam, use an 18/110 needle. Test on a scrap of the actual hem you plan to sew to make sure the needle moves smoothly through all layers.