There are essentially 3 types of denim that we use for our jeans:

The "3 Series" Denim, a 14.5oz selvedge denim. Any jean style starting with a 3 or Z3 or F3 is made from this denim. e.g. 3005 of F380

The "5 Series" Denim, a 14oz selvedge denim. Any jean style starting with a 5 or S5 is made from this denim. e.g. S5003

The "1 Series Denim", a 16oz selvedge denim. Any jean style starting with a 1 is made from this denim.
e.g. 1005

The Frontier Series are style numbers are preceeded by an F:

F310 is a tight straight cut and is our slimmest cut
F350 is a '55 cut, so straight but reasonably loose
F370 is a boot cut
F380 is based on a '66 cut, so somewhere between the F310 and the F350.

The Exceed Series are all made out of the 16oz denim:

1001 is a tight straight cut and is our slimmest cut
1005 is a '55 cut, so straight but reasonably loose
1007 is a boot cut

The Pioneer Series are all made out of our 14.5oz denim

3001 is a tight straight cut (as per F310 and 1001)
3003 is a WWII model (painted arcuates and fewer rivets than normal)
3005 is a '55 cut (as per F350 and 1005)
3006 is a bell bottom
3007 is a boot cut
3008 and 3009 are based on a '66 cut (as per F380)

The Future Series are all made out of our 14oz denim:

S5001 is a tight straight cut (as per F310 etc)
S5005 is a '55 cut
S5003 is a cinch back and the loosest of all our jeans
S5007 is a boot cut
5100 is our 10 year Anniversary model is a little looser than the S5005