As needle size increases, the size and strength thread they can use increases. Unlike needles, thread sizes refer to the weight of a fixed length of thread--not its diameter. Therefore our Needle and Thread Size Chart gives ranges of thread sizes for each needle size.
This chart shows metric and U.S. needle sizes and the range of thread sizes used. Other factors such as the material sewn, the machine's capabilities, and the "look" you want influence needle size selection.
Needle Size Nylon / Polyester / Kevlar Monofilament Spun Threads
Garment and Fire Retardant
Other
50 / 6   Size 003 Tex 10 to 14  
55 / 7   Size 003, 004 Tex 12 to 14  
60 / 8   Size 004, Tex 14 to 18  
65 / 9   Size 004, 005 Tex 14 to 21  
70 / 10 Size 15 Size 005, 006 Tex 18 to 30 40 Weight Embroidery Thread
75 / 11 Size 15 Size 006, 007 Tex 24 to 30 40 Weight Embroidery Thread
80 / 12 Size 15, 33 Size 007, 008 Tex 30 to 35 40 Weight Embroidery Thread
90 / 14 Size 33, 46 Size 008, 009 Tex 35 to 50 30 Weight Embroidery Thread
100 / 16 Size 46, 69 Size 009, 010 Tex 40 to 60 30 Weight Embroidery Thread
110 / 18 Size 69, 92 Size 010, 011 Tex 50 to 90  
120 / 19 Size 69, 92 Size 011, 012 Tex 70 to 90  
125 / 20 Size 92, 138 Size 012 Tex 90 to 120  
130 / 21 Size 138   Tex 120 to  135  
140 / 22 Size 138, 207   Tex 135 to 210  
150 / 23 Size 138, 207   Tex 135 to 210  
160 / 23 Size 207   Tex 210  
180 / 24 Size 207, 277   Tex 210 to 270 Bag Closing Thread
200 / 25 Size 277   Tex 270 to 350 Bag Closing Thread
220 / 26 Size 277, 346   Tex 270 to 350 Bag Closing Thread
230 / 26 Size 346   Tex 350 Bag Closing Thread
250 / 27 Size 346   Tex 350 to 410 Bag Closing Thread
280 / 28 Size 346, 415   Tex 350 to 410  
300 / 29 Size 415, 554   Tex 410 to 600  
330 / 30 Size 415, 554   Tex 410 to 600