Nomex Thread Buying Guide

Nomex (tm) Thread Buying Guide

About Nomex Thread--Nomex is a Type II fire retardant thread. This means that it chars at 675F, begins to decompose at 700F, but never melts, This makes Nomex thread a great thread for safety garments used by first responders,  the military, race car drivers., or sewing any material that is subject to high heat exposure. Nomex thread is expensive and using it only makes sense when there is a critical need for fire retardance and the fabric sewn is equally fire retardant.
Fire retardant is not fire proof--Nomex thread will burn when exposed to a 2500F cigarette lighter. Also, using Nomex thread only makes sense when the fabric is as fire retardant as the Nomex thread.
Nomex and Fire Retardant Sewing Threads - Our Nomex is a filament thread. This means that it has one or more plies that are twisted to make a thread. This gives Nomex a smooth, glossy finish. Spun fire retardant sewing threads are made by wrapping Nomex or Kevlar thread with cotton that results in a cotton-like dull finish. Both threads are fully fire retardant.
Sizes and Usage - Nomex thread in Sizes 46 through 92 correspond to fire retardant sewing threads in the Tex 40 to Tex 90 range. They are used for sewing lightweight and middleweight garments and gear. You can use Sizes 46 and 69 in home sewing machines. Size 92 usually requires a commercial machine.
Sizes 138 and 207 are used for heavy duty jump suits, gloves, and boots. They too require a commercial machine.
Sizes 277 and higher are used for conveyor belts, fire retardant tarpaulins, and wrappings. A heavy duty machine is usually required.
Types of Thread - We have several kinds of Nomex thread and some might not be right for your needs.
  • Bonded - The thread has a coating that reduces needle heat and fraying. This is important for machine sewing in sizes 92 and higher
  • Monocord - The thread is extruded as a single filament and has a coating similar to bonding.
  • Soft - The thread does not have a coating and is not recommended for machine sewing in sizes 92 and higher.
  • Teflon coated - The thread has a waxy, soap-like outer coating. It is great for hand sewing, reinforcing, and wrapping. It is not recommended for machine sewing or applications that use adhesives.
  • Yarn and Multi-End - Use for non-sewing reinforcing and wrapping. They are not recommended for sewing

Specifications (Mil-Spec A-A-50195)

Size

                 

Commercial

46

69

92

138

207

277

346

415

554

Tex

40

60

80

120

180

270

350

410

500

Government

B

E

F

FF

3-Cord

4-Cord

5-Cord

6-Cord

8-Cord

 

                 

U.S.

                 

Break (Pounds)

5.0

7.5

9.0

14.0

18.0

24.0

30.0

36.0

44.4

Yards-Per-Pound

10,000

7,500

5,000

3,200

2,300

1,800

1,400

1,100

930

Diameter (Inches)

0.0082

0.0100

0.0116

0.0142

0.0174

0.0201

0.0225

0.0247

0.0350

 

 

 

 

 

 

 

 

 

 

Metric

 

 

 

 

 

 

 

 

 

Break (kg)

2.3

3.4

4.1

6.4

8.2

10.9

13.6

16.3

20.1

Diameter (mm)

0.2083

0.2540

0.2946

0.3607

0.4420

0.5105

0.5715

0.6274

0.8890