Tandem coil spring

I'm looking for a replacement for my tandem coil spring that has a broken pivot shoe. Stamped on one coil is 6k. The other coil does not have anything stamped on it and the sash weighs 28 pounds. I was looking at possibly replacing it with item S140-14. My concern is that my old coil spring housing has two mounting points and it appears that the S140-14 only has one. Is only one mounting point enough? Is the S140-14 an adequate replacement? The k on the coil is a bit confusing. I've looked all over the internet and can't seem to find much on what the k means after the 6. I'm assuming it's a 6 pound coil in tandem for 12 pounds times 2 would be 24 pounds which would make it slightly under the 28 pound sash weight. Do you guys sell tandem coils for left and right like the one I have pictured?


If I was looking to just replace just the pivot shoe sash carrier would item 15-215 work? My coils do not have a hook at the end. There is only a hole that a screw goes into from the side.

Thanks for the help.

Brian

Thanks for the quick reply! If my sash weighs 28 pounds shouldn't I get the 7lb coil springs item number S152-7? Four of those would equal 28 pounds. It seems like the original coils were a bit under manned. But what do I know ?.

On an unrelated note, do you guys sell/ recommend any certain lubricant?


Thanks,
Brian