Silver SK315 is a standard-gauge knitting machine with 200 needles, 4.5 mm apart. It was released to the market in the very early 1970s.
Silver SK315 is a machine capable of accepting punchcards for patterning and automatic needle selection.
Similar to almost identical Silver SK313 (although SK313 is bright green and SK315 is emerald green), the most prominent and distinct feature of the Silver SK315 is the buzzer, which can sit on top of the punchcard reader and/or on the side.
The buzzer uses batteries to make sound. Sometimes, due to the presence of these batteries, some list these machines as electronic, which they are not. Often these batteries leak because they are super old and because the machine was not stored properly.
Also, similar to SK313, as well as to SK311 and SK312, at the end of the punchcard, you will see the word STOP displayed in the little window above the patterning levers. This STOP word is actually from the punchcard itself. Thus, punchcards for this machine are very easy to distinguish by this giant STOP lettering.
Note that this model still has only one lever on the pattern panel: only to release the punchcard so it advances when the machine knits patterns and is passed back and forth. Later models have two levers: one for card release and one to expand the pattern vertically by a factor of two.
Then you will have to rewind the card to the starting position. The manual describes this feature well (however, I could not find the manual for SK315. But the manuals for SK312 and SK313 are available online for free).
I am not sure if this is the feature of the cards themselves or of the reader. I am yet to work on one of those machines. Later knitting machines allow a constant reading of the card: the card is simply clipped and is ready circular over and over.
All other features are very similar to those of Silver SK313 knitting machine. Thus, read the corresponding blog article.
