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

Important Note: Due to the plating thickness, only hot dipped galvanized nuts should be used on hot dipped galvanized carriage bolts.

Carriage bolt diameter

Diameter and Thread count

Matching Products

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Prod. # Description Buy
2988
USS flat washers, Hot dipped galvanized steel, 5/16"
USS pattern is the most common type of flat washer.
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$0.10 / ea
$5.99 / 100
$52.70 / 1000
2982
Lock washers, Hot dipped galvanized steel, 5/16"
Split lock washers place tension against a nut after tightening, to help prevent loosening.
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$0.09 / ea
$5.28 / 100
$47.00 / 1000