I really have to mention something here about 3and 1 oil. I never use is it on my sewing machines. The original oil for sewing machines was whale oil from the sperm whale. If you think 3and 1 oils is bad try removing whale oil after it sets for years and turns to stone and varnish. Sewing machine oil will will also varnish over after sitting for years as bad as the 3an1 oil. So if the machine is oiled often and used any high grade oil for this purpose will work fine. Why did they use whale oil because that was a light weight oil and cheap for the time. Any machine that sits unused for decades will be gunk up by varnish oil. That being said the sewing machine oil from singer is not much diff than 3 an1. They both have parifin in them. I use clock oil and it will not get hard and stop a clock. Just my opinion and observation. Tri-flow is good to. I guess what I am saying is the old machines we clean up and get sewing have been sitting for years and they are just dirty from old oil(of any kind) so we have to blame it on something. Not to mention the dirt and bugs and mice stuff found in them.