Sash Stamp Weight Range Unknown???

Question

I am purchasing 2 "380" window channel tracks. I do not know which Stamp Option (Sash Weight Range) to indicate. There is nothing marked anywhere on the windows, sashes or channel tracks. How do I know which Stamp Option to order according to the options that are listed below?

Stamp Option / Sash Weight Range
2910 7 to 12 lb
2920 12 to 16 lb
2930 16 to 23 lb
2940 23 to 28 lb
2950 28 to 32 lb
2960 32 to 35 lb
2965 35 to 39 lb

Paul · Accepted Answer

If there is no stamps already on your balances, then you will need to weigh the sash in question by removing it from the window and placing it on a scale. You can then match that weight up to that chart.