The Singer 99K is the baby sister of the Singer 66K.  Or to put it another way, the 66K is the full-size machine, and as such it fits into any vintage Singer domestic treadle base.  A 99K doesn’t, and that’s why if you ever see a treadle 99, it’s a DIY job.

The bed of a 66K is just over 14.5 inches long.  The bed of a 99K is a couple of inches shorter, and getting on for half and inch less front -to-back.  So a 66 will fit into any ordinary “full-size” base and case, even those horrible all plastic ones sold in the late 70’s/early 80’s to “up-date” the classic portables.  A 99 will only fit in either the base it was sold in, or that 99-specific Singer table called the Cadet Cabinet.

Most of the mechanicals are the same on both machines, and in practice when you switch from a 66 to a 99 there’s only two differences.  You lose maybe 2 inches throat space (or what some Americans bizarrely call “harp”), and you save about 6lb in weight, which is definitely noticeable when you cart one about.

Pictured there is a 99K in front of a 66K less its needle plate and slide plate, and as you can see, the difference isn’t exactly obvious.  This of course makes it interesting when a machine’s listed on Ebay, say, by somebody who doesn’t know, or professes not to know, what model it is, and all you have to go on is the usual side-on view of the machine.

OK then, can you tell which is which?

The answer is that the top one’s the 66K, and if you don’t have a picture to compare it with, the easiest way to tell is to look at the gold Singer badge.  On a 66K, the top of the badge is level with what is properly called the stitch regulating thumb screw.  On a 99K, the badge is well below it.

And you’d be surprised how many people don’t know that …