Polyester Thread Specifications - Here are U.S. military specifications (MIL-DTL-32072 / VT-285F) for polyester thread. Please note:
  • Polyester thread sizes are based on the ratio of a fixed length of thread to its weight - not its diameter. This is because thread is spongy and its diameter cannot be measured with calipers.
  • Bonding slightly increases a thread's thickness and density. As a result, yards-per-pound are reduced.
  • Average Break Strength is for twisted thread. Monocord threads are 10% to 14% stronger
  • Metric data is calculated using standard conversion factors. Small rounding differences are inevitable.
  • Needle size ranges come from other sources and are not part of the mil-spec.

Lightweight and Middleweight - Sizes 15 to 138
Size size 15 size 33 size 46 size 69 size 92 size 138

Tex

 16 35 45 70 90 135

Military

 A AA B E F FF
Ave. Break Strength            

Pounds

 1.5 3.0 7.0 11.0 14.5 21.0

Metric

 0.7 1.4 3.2 5.0 6.6 9.5
Diameter            

Thousandths of Inch

 .0047 .0070 .0080 .0107 .0124 .0152

Millimeters

 0.1194 0.1778 0.2032 0.2718 0.3150 0.3851
Average Per Pound            

Yards

 30,000 12,200 9,500 6,000 4,500 3,000

Meters

 27,272 11,090 8,636 5,454 4,091 2,727
Needle Size Range            

U.S.

 10-12 12-14 14-16 16-18 18-20 20-22

Metric

 70-80 80-90 90-100 100-110 110-120 120-140

Heavyweight - Sizes 207 to 554
Size size 207 size 277 size 346 size 415 size 554  

Tex

 210 270 350 410 600  

Military

 3-Cord / 18 4-Cord 5-Cord 6-Cord 8-Cord  
Ave. Break Strength            

Pounds

 31.0 44.0 53.0 73.0 98.0  

Metric

 14.1 22.0 24.1 37.7 44.5  
Diameter            

Thousandths of Inch

 0.0186 0.0231 0.0258 0.0283 0.0330  

Millimeters

 0.4724 0.5867 0.6553 0.7188 0.8382  
Average Per Pound            

Yards

 2,100 1,500 1,300 1,000 630  

Meters

 955 682 591 455 286  
Needle Size Range            

U.S.

 22-24 24-26 26-28 28-30 30-32  

Metric

 140-180 180-220 220-260 260-300 300-360