Bonded thread is heavier than ordinary all-purpose thread, so check the exact machine manual before putting it on a home machine. A thread supplier’s needle chart can help with a starting needle size, but it does not prove that a particular machine can feed the thread, accept it in the bobbin, or form a reliable stitch.
Superior Threads lists these home-machine needle examples for its bonded thread:
| Bonded thread size | Supplier-listed home-machine needle example |
|---|---|
| #46 | Topstitch or Leather 90/14 |
| #69 | Topstitch or Leather 100/16 |
| #92 and heavier | Not recommended for home machines in that supplier’s chart |
These are the supplier’s recommendations, not universal machine ratings. SINGER’s Heavy Duty 6800C support page, for example, lists bonded nylon and polyester no larger than #69/Tex 70 among acceptable examples for that specific model. Do not transfer that limit to another SINGER machine or another brand.
Before testing, identify the exact thread construction and size, confirm the permitted needle system and thread range in the machine manual, and check whether the manual allows the intended bobbin thread. Choose a needle whose eye carries the thread freely and whose point suits the material. Sew slowly on scrap with the actual layers. Stop if the thread shreds, the needle bends, the machine jams, or stitch formation remains poor.
If the manual does not list the thread or the setup remains uncertain, use a lighter machine-compatible thread or ask the manufacturer before sewing. Read the thread and needle matching guide for size-label and eye-fit checks.