Hex bolt diameter is measured on the outside of the threads.

Hex bolt diameter

Diameter and Thread count

Matching Products

Click on a product # for additional info

Prod. # Description Buy
3053
SAE flat washers, Zinc plated grade 8 steel yellow, 5/8"
SAE pattern is a tighter fit on the bolt and a smaller outside diameter.
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$0.56 each
$7.55 / 25
$67.10 / 250
3066
USS flat washers, Zinc plated grade 8 steel yellow, 5/8"
USS pattern is the most common type of flat washer.
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$0.49 each
$9.40 / 25
$79.40 / 250
3043
Lock washers, Zinc plated grade 8 steel yellow, 5/8"
Split lock washers place tension against a nut after tightening, to help prevent loosening.
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$0.24 each
$3.91 / 25
$35.10 / 250

See also

Metric hex bolt

Metric hex bolts

A bolt with a six sided head.