UNF part threaded hexagon head bolts.
1/4UNF x 28tpi.
Thread diameter 1/4".
Spanner size 7/16".
Head height 0.163"
5/16UNF x 24tpi.
Thread diameter 5/16".
Spanner size 1/2".
Head height 0.211"
3/8UNF x 24tpi.
Thread diameter 3/8".
Spanner size 9/16".
Head height 0.243"
7/16UNF x 20tpi.
Thread diameter 7/16".
Spanner size 5/8".
Head height 0.291"
1/2UNF x 20tpi.
Thread diameter 1/2".
Spanner size 3/4".
Head height 0.323"
Bolt lengths do not include the head.