Spiral Balance Tip Color = what weight?

Question

I ordered 6 blue tip spiral balances, for my old Alcoa vinyl windows, to replace the old blue tip spiral balances.
After replacing the 2 balances in 1 window, I charged the balances equally.
The sash still drops like a ton of bricks.  I even tightened them another turn back and forth, testing the sash each time.
In the end, one of my blue tip balances snapped and broke and still wasn't strong enough to hold the sash up before that.
Is it possible that I need green or black tips?
Is there a specific weight that each color will hold when charged properly?

Casey · Accepted Answer

First, check to see if the new balances matched up to the length of the original balances.

Next, remove the window sash and place it on a scale.

S600-29 with Blue tip will carry a window sash weight range of 12 through 31 pounds

S600-29 with Black tip will carry a window sash weight range of 31 through 40 pounds

This information is based on 2 balances per sash. Balances are designed assuming friction in the jamb weather-strip will carry a portion of the sash weight. Suggested sash weights are approximate.