Heavier Grade Balances
Thanks,
Many thanks for your post. First, please recheck the balance channel lengths. Be sure to metal the metal channel itself, and do not include the nylon fittings in the measurement. For a 25C stamp the length should be 26". For your Alenco window that uses 26" balances, I'd expect to see the S395-26. You should weigh the sash with the heavier glass and see where it falls among our stamp option ratings, which are listed under the product description. The 25C stamp is equivalent to our 2530, for a sash weighing between 15 through 19 lbs. The 2540 stamp meanwhile will support a window sash in the range of 19 through 25 lbs. See the chart on the product page for further rating information.
For the 25" balance, I expect you will need our S395-25 and spring weight 2465 would be for sash weighing between 30 through 33 lbs. Again, I advise to please weigh your sashes before ordering.