Extra Strong Bonded Nylon Thread #138 Tex135 16 OZ - Heavy Duty Dark

In this review of the Extra Strong Bonded Nylon Thread #138 Tex135, the bottom line is simple: this commercial-size spool is aimed at makers and repair professionals who need a reliably tough, heat-resistant thread for leather, upholstery and canvas work. The single biggest reason to buy is the thread's construction: 100% nylon 6.6 with meticulous twisting and a high-performance lubricant produces smooth needle passage and fewer broken or skipped stitches under heavy use. For anyone stitching protective footwear, automotive interiors, or heavy outdoor gear, this thread delivers the durability you expect from a heavy duty option.

Key Features

• Premium construction: Made from 100% nylon 6.6 with careful twisting for strand cohesion, which improves long-term strength and stitch integrity.
• Bonded and lubricated: Special lubricant and bonding chemistry reduce needle friction and minimize breakage and skipped stitches during heavy sewing.
• Heat and abrasion resistance: Treated to endure high temperatures and resist abrasion, making it suitable for demanding environments and prolonged use.
• Consistent color: High-temperature dyeing produces uniform, fade-resistant dark gray that holds up in sunlight and washing.
• Commercial size: The 1 lb cone contains 3000 yds of #138 Tex135 thread, reducing spool changes for large projects and production runs.
• Stretch control: Controlled elasticity yields tight, smooth stitches that remain secure without puckering flexible materials.

Who It's For

This thread is best for leatherworkers, upholstery professionals, custom automotive interior shops, tent and sail makers, and serious DIYers who work with thick materials and need a dependable heavy duty thread. Its commercial #138 size and 3000 yd length suit continuous production or a long run of large projects.

Hobbyists who only do occasional light mending or need fine decorative stitching should look for a finer, lighter thread. Also, if a project requires a non-nylon fiber (for extreme heat exposure where nylon could soften) choose a specialty fiber instead.

Pros & Cons

Pros

• Exceptional tensile strength and abrasion resistance for demanding sewing tasks.
• Bonded coating prevents untwisting and peeling, keeping seams reliable over time.
• Large 3000 yd cone reduces interruptions for professionals and long projects.
• Fade-resistant dye maintains consistent dark gray color across batches.

Cons

• Thicker #138 diameter may be overkill for delicate or decorative sewing projects.
• Being nylon, it is not ideal where prolonged exposure to very high direct heat could soften the fiber.

Specifications

Brand	HILOHILO
Material	100% nylon 6.6 bonded
Size	#138 / Tex135 / Tkt20
Length	3000 yds (1 lb cone)
Diameter	0.41 mm
Average Strength	22 lbs
Recommended Needle	140/22 or 160/23

Our Verdict

The Extra Strong Bonded Nylon Thread #138 Tex135 is a solid choice for professionals and serious hobbyists who need a durable, bonded nylon suitable for leather, upholstery and heavy canvas work. Its commercial length, bonded coating and heat-resistant lubricant give reliable stitching with fewer breaks, making it good value for large projects where seam strength matters most.

Frequently Asked Questions

Is this thread suitable for leather sewing?
Yes. The bonded nylon construction, diameter, and recommended heavy needles make it well suited to leather and upholstery stitching.

What needle size should be used?
Use heavy sewing needles such as 140/22 or 160/23 for best performance with this #138 thread.

How colorfast is the thread?
Colors are produced by high-temperature dyeing for uniform, fade-resistant results under normal use and exposure.