Flexible Stranded Wire Information

Traditionally bare wire terminals used on Power Blocks and Fuse Holders have only been evaluated for use with rigid (Class B & C) wire. The majority of MSP’s terminals have been evaluated for use with flexible stranded wire classes such as Class G, H, I (DLO) and K per UL 486A-B. This enables customers to be UL and NEC compliant while using flexible classes of wire without the use of crimp type terminals. We also supply a range of studded products to allow for the use of crimp terminals, which are recommended for larger wire sizes (greater than #1 AWG).

Flexible stranded wire classes also bring additional considerations to address such as an increase in wire diameter and the number of strands per a given wire size. The photo to the right shows two 250 kcmil wires of different classes. The one on the left is the traditional Class B with 37 strands. The one on the right is a finely stranded Class K. Although they are the same wire classification of 250, you can see the Class K is larger in diameter. This illustrates the need to specify a terminal to accept a larger standard wire size. The table below shows the increase in strand count per each wire size.

flexible stranded wire

Flexible Stranded Wire Table
Wire Gauge AWG/kcmil Wire Gauge
Rigid Stranded Flexible Stranded
CSA Compact Class B Class C Class G Class H Class I (DLO) Class K
Number of Strands*
#20 AWG -- 7 19 -- -- -- 10 #20 AWG
#18 16 #18
#16 26 #16
#14 19 41 #14
#12 65 #12
#10 27 104 #10
#8 7 49 133 41 168 #8
#6 63 266 #6
#4 105 420 #4
#2 161 665 #2
#1 19 19 37 133 259 210 836 #1
1/0 266 1064 1/0
2/0 342 1323 2/0
3/0 418 1666 3/0
4/0 532 2107 4/0
250 kcmil 37 37 61 259 427 537 2499 250 kcmil
300 kcmil 735 2989 300 kcmil
350 kcmil 882 3458 350 kcmil
400 kcmil 980 3990 400 kcmil
500 kcmil 1225 5054 500 kcmil
600 kcmil 427 1470 6065 600 kcmil
750 kcmil 61 1850 7581 750 kcmil
1,000 kcmil 2527 10101 1,000 kcmil

* Specific quantity of strands for Classes G, H, I (DLO) & K may vary by manufacturer.