Please help me find replacement

Question

My window balance says 30 5 GP caldwell on it.

I would like to upgrade the weight to 60 lbs (I believe it is rated for 50).

I measure JUST THE METAL portion and it is 31 inches - not sure why it says 30 on it.

The width is 1/2" and the depth is 3/8".

I have included pictures of the ends. The width of the bottom shoe is 1".

Can you help? I only have one window this size so I need two of the parts.

Tom · Accepted Answer

Well, let's take a step back.

I'm not sure if you mean your shoe is 1" side to side, or front to back. You have a Series 351 balance (S351-31) if your shoe measures the same as the 1" shoe shown below.

As far as the weight, a "30 5" balance would usually be rated for far less than 50 pounds; more like 28 to 32 pounds. Before considering any change in the spring strength, weigh your window and compare to this chart. Your "30 5" is the modern "3050."

Stamp Option	Sash Weight Range
3010	7 to 12 lbs
3020	12 to 16 lbs
3030	16 to 23 lbs
3040	23 to 28 lbs
3050	28 to 32 lbs
3060	32 to 35 lbs

72