On Feb 4, 12:45 pm, wrote:
On Feb 4, 1:33 pm, "Joe" wrote:

Getting ready to stock up for summer projects at Menards 17% sale.
Some roofing planned, single shingles over 1/2" plywood and OSB. Saw
some commercial projects lately with a lot of the nail length hanging
down below the OSB. Seems to me the extra length is wasted, hence the
question about optimum length. Would 1 1/2" be best for a decent
quality shingle and 30 lb. felt?

Joe

As long as the nail is long enough to penetrate all the way through
the plywood or osb you should be in good shape.

some shingle wrappers state that the nail mush penetrate the sheathing
by 1/8". I most commonly see roofers using 1 1/4" nails.