A home owner from USA says:
April 15, 2015
I am trying to match a channel balance and sash guide...when I type in the stamp number to help identify the balance it measures metal end to metal end 35" but the shoe, top and sash guides don't match...the stamp is 3440 PR BSI....the sash weight is 50 lbs...I have attached pictures with measurements...thank you for you assistance..
Tom from SWISCO responded:
April 16, 2015
Thanks for posting. Stamp numbers actually only tell you how strong the spring is, it is not a part number. I recommend looking at our Series 380 channel balance for a possible replacement and see if the nylon attachments match. Keep in mind your shoe may have worn down over age, which would account for a depth of 7/8", not 1". Even if your original shoe depth was 7/8", you could file down the Series 380 shoe if necessary. They do not make a shoe in this style that has that size so that may be your only option.
Please also confirm the weight of your sash. 50 pounds is a lot! Plus, your stamp of 3440 is only meant for sashes that weigh 23 through 30 pounds. If your sash was 50 pounds, these balances would never have been able to support that kind of weight. Please double check.
As for the top sash guide, see our 18-161.