In the spirit of K7LXC's sage advice "do what the manufacturer recommends"
I dug out the Preformed Line Products catalog and here's what it sez:
Nominal Strand Size Recommended Thimble Size
"Only heavy duty thimbles are recommended"
3/8" heavy duty open pattern thimbles cost only about 25 cents more than
A related item from the Preformed catalog:
Regarding "Guy-Grips" (the product typically used by electric, telephone
and cable TV companies for their distribution lines) the Preform catalog
"Guying of transmission structures and metal towers require Big-Grip
dead ends" ^^^^^^^
"Big-Grip dead-ends are recommended for use on transmission and antenna
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