Sewing

You inherited the machine. Not the manual.

Start with one of these questions

• Which needle, and what do the numbers mean?

  “The packages say 130/705 H and 90/14. Which goes in my machine, and which for my fabric?”

  130/705 H, 90/14, Universal, Jersey, Microtex. What the system number means, why the size is one number written twice, and how point type maps to how a fabric is constructed rather than what it is called.

  Decode the needle package

• Class 15, 15J, L or M?

  “No manual, one bobbin, and they all look the same in the listing. Which do I buy?”

  They look identical in a photograph and are not interchangeable. How to measure the bobbin or the bobbin case you already have against published dimensions, and what a near-fit actually does to the machine.

  Measure and identify yours

• Does "universal" mean mine?

  “The listing says 'universal, fits most machines'. How do I know it fits mine?”

  Shank height is not the first thing to check. The four properties of your machine that decide whether a foot fits and runs safely, in the order that matters, and why some feet strike the needle.

  Check the four properties

• Nearly every home sewing machine takes the same needle. SCHMETZ states that needle system 130/705 H "is used by 99% of all home sewing machines"; 130/705 means the shank has a flat side, and the H is from Hohlkehle, German for the scarf — the small indentation behind the eye. 15x1 H and HAx1 are cross-references for that same needle, so a package marked with any of the three is the same thing. The exception that catches people is a serger: SCHMETZ documents that newer sergers use 130/705 H, older ones use BLx1 or DCx1, and many overlock and coverlock machines use ELx705, which has a second groove a home needle does not have.
• The two numbers on a needle package are one needle described twice. The first is the metric NM size — the blade diameter in hundredths of a millimetre, a European designation established in 1942 — so 80 means 0.80 mm. The second is the older American (Singer) number. 80/12 is a single needle, not a choice. Groz-Beckert's published range runs Nm 55/7, 60/8, 65/9, 70/10, 75/11, 80/12, 85/13, 90/14, 100/16 and 110/18.
• Bobbin class is set by machine model, not by brand. In a published 580-row machine-to-bobbin chart, Bernina's 440 and 440QE take Class 15 while the 450 takes L-style; the 163 takes Class 15 while the 165 Artista takes L-style; Singer's 221 and 222 Featherweights take a bobbin unique to models 221, 221K, 222 and 301. Across that chart roughly 315 rows are Class 15, 180 L-style and 70 M-style. Knowing you own "a Singer" or "a Bernina" does not tell you which bobbin to buy.
• Two bobbins can share a class name and still not substitute. SINGER's own support page gives Class 15 transparent as 7/16" (12 mm) tall and 13/16" (21 mm) across with completely flat ends, and Class 15J as 6/16" (11 mm) tall and 3/4" (20 mm) across with tops and bottoms "very slightly curved" — a one-millimetre difference in each direction. SINGER also says not to substitute Class 15 metal for Class 15 transparent, or the reverse, even though both are "Class 15".
• Before you buy a presser foot, three things about your machine decide the fit — and shank height is not the first one. Janome's own quick-reference guide asks, in order: where do you insert your bobbin (horizontal rotary hook, or front-loading vertical oscillating hook); what is the maximum stitch width (9 mm, 7 mm or 5 mm — set the machine to maximum, sew a zig-zag, and measure it); and only then shank height, which the guide says "is only needed if you require a presser foot that attaches directly to the presser foot bar." Janome names its own high-shank exceptions: every machine with AcuFeed, plus the MC6650, MC9850 and Skyline S5.