A gloat, for me anyway.

[Dave C]

Got these at the local surplus store for $.25 each. Please disregard the messy workbench, and my home built spill proof oil pot. The links and hooks are are 5/16.

[sch]

Pretty good price even if east asian in origin, which is not clear from the pix. If US made, wow. Now all you need is some chain.
My time frame for such as this was 25-30 yrs ago when I had a tractor and was installing the machinery in the basement. Last
time I used such was 3 yrs ago to swing a 1000# machine onto a pad under the deck. Used slings and an HF chain fall for that
with lifting point a doubled 2x10 joist braced with a 4x4 under neath. Didn't want to pull the deck down.

[Glug]

Great deal. Is there any rating on the links?

[Dave C]

No rating marks, but these are Blue Hawk brand sold at Lowe's. All are Chinese made, and use will require taking that into consideration.

[Glug]

I thought about using a fairly large threaded link - half inch - to move a machine a while back. I always considered those quite strong due to the closed form when shut. The site rep wouldn't allow it because there was no rating, or even marks of any kind. He was completely correct - no rating is no rating. Had something happened, he would have been in a lot of trouble, or worse. A rated forged shackle is what I needed to use. I still like the threaded links for lighter stuff.

[Dave C]

They are handy, but you have to keep in mind their size and the absence of any rating marks. Fine for keeping a lawn tractor in place while transporting on a trailer, but not something I would trust to pull an engine out of a car. Just checked Lowe's web site, the 5/16 quick link is rated at 1760 lbs. working load.