Choosing bonded nylon thread starts with four factors: material thickness, application, required seam strength and sewing machine / needle compatibility.
As the Tex size increases, the thread becomes heavier and produces a larger, more visible stitch. The right size is not simply the largest thread your machine can handle — it should match the material, seam requirement and stitch appearance you want.
Start with these four questions:
- How thick and dense is the material?
- What will the finished product be used for?
- How visible and substantial should the stitch look?
- Can your machine, needle system and bobbin setup handle the thread size?
1. How to Choose the Right Bonded Nylon Thread Size:
Bonded nylon thread size affects more than seam strength. It also changes stitch appearance, needle requirements, machine setup and how much thread bulk is added to the finished seam.
A lighter size such as Tex 70 creates a finer stitch and is useful when you want less visual bulk. Moving through Tex 90 and Tex 135 produces progressively more visible seams for medium and medium-heavy applications. Tex 210 and Tex 270 create much heavier stitches and require equipment that can properly accommodate larger thread.
The correct choice depends on the complete sewing system — not only the thread.
2. Quick Bonded Nylon Thread Size Guide:
| Thread Size | Stitch Profile | Typical Applications | Material Fit | Machine Guidance | Confirmed Needle Guidance | Choose It When |
|---|---|---|---|---|---|---|
| Tex 70 (#69 / 210D/3) | Finer, cleaner | Footwear, leather goods, bags, detailed sewing | Lighter to moderate assemblies | Machine must handle Tex 70 consistently | Size 16–18 / Metric 100–110 | You want a cleaner stitch with less bulk |
| Tex 90 (#92 / 280D/3) | Balanced, visible | Leather, bags, footwear, upholstery | Moderate materials | Machine must properly handle Tex 90 | 110/18–125/20 | Tex 70 feels too fine but Tex 135 is larger than needed |
| Tex 135 (#138 / 420D/3) | Medium-heavy, prominent | Leather, bags, upholstery, canvas | Medium-heavy assemblies | Heavy-duty / industrial machine | 130/21–140/22 | You want a stronger, more visible stitch without moving to very heavy thread |
| Tex 210 (#207 / 630D/3) | Heavy, substantial | Heavy leather, canvas, webbing, heavy-duty bags | Heavy materials | Heavy-duty / industrial machine | 140/22–180/24 | Tex 135 is too light for the material or desired seam profile |
| Tex 270 (#277 / 840D/3) | Very heavy, highly visible | Thick leather, heavy canvas, webbing, substantial assemblies | Thick / very heavy materials | Equipment must be configured for very heavy thread | 140/22–160/24 | You specifically need a very heavy thread and large stitch |
Needle ranges are starting points based on the confirmed NEXUS product guidance. Final needle selection still depends on the material, machine, needle system and stitch result. Always test the complete setup before production.
3. Choose Bonded Nylon Thread by Material:
Thread size should follow the material construction rather than a generic “light / heavy” label. Material thickness, stiffness, seam layers and the required finished appearance all matter.
Leather
For leather goods that need a finer, cleaner stitch, start by comparing Tex 70 and Tex 90.
Move toward Tex 135 when the leather assembly is heavier or when you want a more prominent stitch.
For thick leather and heavier assemblies, Tex 210 may provide the larger seam profile you need. Tex 270 should be considered only when the material and equipment genuinely call for a very heavy thread.
Related products:
Tex 70 → Tex 90 → Tex 135 → Tex 210 → Tex 270
Footwear
Bonded nylon thread is widely used in footwear where the stitch is part of both the construction and the visible design.
Tex 70, Tex 90 and Tex 135 can be used for upper stitching and decorative seams on shoe uppers, depending on the material thickness and the desired stitch appearance.
- Tex 70 creates a finer, cleaner stitch for lighter or more detailed upper work.
- Tex 90 provides a more visible middle-size stitch for shoe uppers and decorative seams.
- Tex 135 creates a heavier and more prominent stitch where a bolder upper seam is preferred.
For decorative stitching along the side of a rubber outsole, Tex 270 can be used when a very large, highly visible stitch is required and the machine is properly configured for that thread size.
Choose the thread size according to the upper material, outsole construction, desired visual effect and machine capability rather than using one size for all footwear applications.
Bags & Accessories
For wallets, handbags, pouches and similar products, choose thread according to material thickness and how visible the seam should be.
- Tex 70 — finer stitch
- Tex 90 — balanced stitch
- Tex 135 — larger, more prominent stitch
- Tex 210 — for substantially heavier bag or case constructions
Avoid choosing a larger Tex size only because it appears “stronger.” Excessive thread bulk can change the finished appearance and may exceed what the material or machine needs.
Upholstery
For many indoor upholstery applications, Tex 90 or Tex 135 provide useful starting points depending on seam construction and stitch appearance.
Move toward Tex 210 only where heavier materials and a larger seam justify it.
For upholstery exposed to prolonged sunlight or outdoor weather, thread material matters as much as size. In those conditions, compare bonded nylon with bonded polyester before choosing.
Canvas, Webbing & Heavy Assemblies
Canvas and webbing vary considerably in thickness and construction.
Moderate canvas projects may work with Tex 90 or Tex 135, while heavier canvas, webbing, straps and substantial assemblies may call for Tex 210 or Tex 270.
Always confirm that the machine, bobbin, thread path and needle system can accommodate the selected thread.
4. Choose Bonded Nylon Thread by Stitch Appearance:
Thread size changes the visual character of the seam.
Tex 70
Produces the finest stitch among the five NEXUS sizes covered here. Choose it when a cleaner, less bulky seam is preferred.
Tex 90
Creates a balanced and clearly visible stitch without the heavier appearance of Tex 135.
Tex 135
Produces a stronger visual presence and is useful when the stitch should become part of the finished appearance.
Tex 210
Creates a large and prominent seam for heavier materials and more substantial constructions.
Tex 270
Creates the heaviest and most visually dominant stitch in this range. Use it only when the material, equipment and finished design support that size.
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A larger thread is not automatically the better choice. Select the size that gives the required seam performance without adding unnecessary bulk or exceeding your sewing setup.
5. Choose by Sewing Machine and Needle
The thread, needle, machine and material have to work as one system.
Before changing to a heavier bonded nylon thread, check:
- whether the machine can feed the thread consistently
- whether the needle system supports the required needle size
- whether the bobbin and thread path can accommodate the larger diameter
- whether tension can be balanced without damaging the material
- whether the stitch appearance suits the finished project
Confirmed NEXUS Starting Needle Guidance
- Tex 70: Size 16–18 / Metric 100–110
- Tex 90: 110/18–125/20
- Tex 135: 130/21–140/22
- Tex 210: 140/22–180/24
- Tex 270: 140/22–160/24
Always test on the actual material before final production.
6. Tex 70 vs Tex 90
Choose Tex 70 when you want a finer stitch, less thread bulk and a cleaner appearance — particularly for footwear, smaller leather goods and detailed machine sewing.
Choose Tex 90 when you want a more visible middle-size stitch for leather, bags, footwear or upholstery without moving to the heavier profile of Tex 135.
Simple decision:
If Tex 70 looks too fine, move to Tex 90.
If Tex 90 already gives the seam profile you need, there is no reason to move larger.
Links: View Tex 70 | View Tex 90
7. Tex 90 vs Tex 135
Choose Tex 90 when you want a balanced stitch for moderate materials.
Choose Tex 135 when the material is heavier, the seam requires a larger thread, or the stitch is intended to be more prominent.
Tex 135 is not automatically better than Tex 90 — it is simply a heavier thread size with different machine and visual requirements.
8. Tex 135 vs Tex 210
Choose Tex 135 when you need a medium-heavy thread for leather goods, bags, upholstery and similar projects without excessive bulk.
Move to Tex 210 when the material, seam construction or finished stitch requires a substantially heavier thread.
Tex 210 also requires a sewing setup that can reliably handle the larger thread size.
Links: View Tex 135 | View Tex 210
9. Tex 210 vs Tex 270
Both are heavy thread sizes, but they should not be treated as interchangeable.
Choose Tex 210 when you need a heavy, prominent seam for heavy leather, canvas, webbing and similar applications.
Choose Tex 270 when you specifically need a very heavy thread, a large stitch and equipment capable of handling that size.
For many projects, Tex 270 may add more bulk than necessary. Moving to the largest thread size should be a deliberate material and sewing decision.
10. Common Bonded Nylon Thread Selection Mistakes
Choosing the Largest Thread for “More Strength”
Thread size should match the seam and material. A larger thread may require a larger needle, heavier machine setup and more material clearance. Bigger is not automatically better.
Ignoring Stitch Appearance
A thread can technically sew a material but still produce a stitch that looks too heavy or too fine for the finished product.
Choosing Thread Without Checking the Machine
Moving from Tex 90 to Tex 210 or Tex 270 changes more than the thread. Confirm machine, needle, bobbin, thread path and tension compatibility first.
Treating Bonded Nylon as the Best Choice for Every Outdoor Project
Bonded nylon is widely used where strength and abrasion resistance matter, but prolonged UV exposure can reduce nylon performance over time.
For marine, awnings, outdoor upholstery and other applications with long-term sunlight exposure, bonded polyester is often the better material choice.
Selecting Color Only from a Screen
Monitor settings, lighting and photography can change how a thread color appears online.
Use the NEXUS physical color chart when color accuracy matters, and use pre-shipment photo verification as an additional review step before shipment.
11. Which Bonded Nylon Thread Should You Choose?
Use this simple progression:
Choose Tex 70
when you want a finer stitch for footwear, leather goods, bags or detailed sewing.
Choose Tex 90
when you want a balanced middle-size thread for leather, bags, footwear and upholstery.
Choose Tex 135
when you need a medium-heavy, more prominent stitch for heavier leather, bags, upholstery or canvas.
Choose Tex 210
when Tex 135 is too light for the material, seam requirement or desired stitch appearance.
Choose Tex 270
only when the project requires a very heavy thread and your equipment can properly accommodate it.
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Still comparing sizes? Review the individual product specifications and confirm your material, needle and machine setup before ordering.Compare All Bonded Nylon Thread Sizes
12. Frequently Asked Questions
Is a higher Tex number a thicker thread?
Yes. Within the same thread system, a higher Tex number represents a heavier thread. For example, Tex 135 is heavier than Tex 90, while Tex 270 is substantially heavier than Tex 135.
Is a larger bonded nylon thread always stronger?
A larger thread can provide greater seam capability, but that does not mean the largest thread is automatically the best choice. Material thickness, stitch appearance, needle size and machine compatibility must also be considered.
What bonded nylon thread size should I use for leather?
There is no single size for all leather. Finer leather sewing may use Tex 70 or Tex 90, while heavier leather projects may call for Tex 135 or Tex 210. Tex 270 should be reserved for very heavy applications where both the material and machine justify the larger thread.
Can I use bonded nylon thread outdoors?
Bonded nylon can be used in some outdoor gear and abrasion-heavy applications, but prolonged sunlight exposure can gradually reduce nylon strength. For long-term UV, marine or outdoor exposure, compare bonded polyester before choosing.
How do I choose a needle for bonded nylon thread?
Start with the confirmed needle guidance for the thread size, then adjust according to your material, machine and stitch result. The complete setup should always be tested before production.
How should I choose the thread color?
Compare the thread against the actual material under relevant lighting. When color selection is important, use a physical color chart rather than relying only on screen images.
