Steel Crochet Hook Sizes: Chart From 00 to 14, Thread and Lace Weight
Steel crochet hooks run in reverse: the higher the number, the finer the hook. Size 00 is 3.5 mm and size 14 is 0.75 mm. CYC pairs lace weight yarn, which includes 10-count crochet thread, with steel hooks 6 to 8, about 1.4 to 1.6 mm, so check millimeters because brands differ.
Steel crochet hooks are the fine hooks used for crochet thread, doilies, lace edgings and very fine yarn. Unlike regular aluminum hooks, which are labeled with letters that grow with the hook, steel hooks are numbered in reverse: size 00 is the largest and size 14 the smallest. Published charts disagree on the exact millimeters for many sizes, so both figures are shown.
What are the steel crochet hook sizes in mm?
| Steel size | Metric | Alternate chart | Same mm as a regular hook | CYC lace weight range |
|---|---|---|---|---|
| 00 | 3.5 mm | 2.7 mm | E-4 | No |
| 0 | 3.25 mm | 2.55 mm | D-3 | No |
| 1 | 2.75 mm | 2.35 mm | C-2 | No |
| 2 | 2.25 mm | 2.2 mm | B-1 | No |
| 3 | 2.1 mm | Same | No | No |
| 4 | 2 mm | Same | No | No |
| 5 | 1.9 mm | 1.7 mm | No | No |
| 6 | 1.8 mm | 1.6 mm | No | Yes |
| 7 | 1.65 mm | 1.5 mm | No | Yes |
| 8 | 1.5 mm | 1.4 mm | No | Yes |
| 9 | 1.4 mm | 1.25 mm | No | No |
| 10 | 1.3 mm | 1.15 mm | No | No |
| 11 | 1.1 mm | 1.05 mm | No | No |
| 12 | 1 mm | Same | No | No |
| 13 | 0.85 mm | 0.95 mm | No | No |
| 14 | 0.75 mm | 0.9 mm | No | No |
Two millimeter standards
Manufacturers have not agreed on steel hook diameters, so the metric and alternate columns can differ by 0.1 to 0.3 mm for the same number. The millimeter size stamped on the hook is the one to follow.
What size crochet hook do you use for size 10 thread?
The Craft Yarn Council puts 10-count crochet thread in its lace weight category, category 0, alongside Fingering (CYC type), 10-count crochet thread, Cobweb, Light fingering. Its hook recommendation for that category is below.
| Includes | Fingering (CYC type), 10-count crochet thread, Cobweb, Light fingering |
|---|---|
| Recommended hooks | 1.4 to 2.25 mm (Steel 8 to B-1) |
| Crochet gauge (double crochet, per 4 in) | 32 to 42 |
| Knit gauge (per 4 in) | 33 to 40 stitches |
| Wraps per inch | 30 to 40 or more |
| Yards per 100 g | 600 or more |
See the full lace weight yarn guide for needles and yardage. Thread crochet patterns almost always name the hook, and a slightly smaller hook gives the crisp, firm stitches doilies need.
See fine thread stitches clearly
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How do steel hooks compare with regular crochet hooks?
The steel and regular systems overlap only at the largest steel sizes. Everything finer than 2.25 mm is steel-only territory.
Frequently asked questions
What size crochet hook for size 10 thread?
The Craft Yarn Council groups 10-count crochet thread with lace weight yarn and lists steel hooks 6, 7 and 8, about 1.4 to 1.6 mm, plus the regular 2.25 mm B-1 hook at the top of the range. Many thread crocheters start on a size 7 steel hook, 1.65 mm on one chart or 1.5 mm on another, then go down a size for tighter doilies. Thread patterns usually name the hook, so follow the pattern first.
Why do steel crochet hook sizes go backwards?
Steel hook numbers follow an old wire-gauge style system where a bigger number means a thinner hook, the opposite of US letter hooks. That is why a size 14 steel hook is only 0.75 mm while size 00 is 3.5 mm. Old UK knitting needle and hook numbers work the same way. The millimeter size is the only unambiguous label, so buy and follow patterns by millimeters.
Why do some charts list two millimeter sizes for one steel hook?
Manufacturers have never agreed on steel hook diameters, so published charts carry two sets of figures. Size 6, for example, is listed at 1.8 mm on one chart and 1.6 mm on another, and size 8 at 1.5 or 1.4 mm. A difference of 0.1 to 0.2 mm is enough to change thread gauge, so read the millimeter stamp on the hook you own.
What is the difference between steel and aluminum crochet hooks?
Steel hooks are made for thread and very fine yarn, in sizes below the regular aluminum range. The two systems only overlap at the large end: steel 00 is 3.5 mm like the E-4, steel 0 is 3.25 mm like the D-3, steel 1 is 2.75 mm like the C-2 and steel 2 is 2.25 mm like the B-1. Steel keeps a crisp, narrow throat at tiny diameters that aluminum cannot, which helps catch thin thread cleanly without splitting it.
Do I need a magnifier for thread crochet?
Many people find it much easier with one. At 0.75 to 3.5 mm, each stitch in crochet thread is tiny, and a dark thread in low light is hard to read. A daylight lamp with a magnifying lens, or a hands-free magnifier, reduces squinting and lets you work longer. If your eyesight has changed recently, an eye doctor can suggest the right magnification strength.
What size is a size 7 steel crochet hook?
A size 7 steel hook is 1.65 mm on one common chart and 1.5 mm on another. Either way it sits in the middle of the steel 6 to 8 range that CYC pairs with lace weight yarn and 10-count thread. The next sizes are steel 6 at 1.8 mm and steel 8 at 1.5 mm. For size 20 or finer thread, crocheters typically move to higher numbers.
How we research: we compare manufacturer specifications, owner manuals, published standards and recurring themes in verified owner reviews. We do not test products in person, and this is researched guidance, not professional advice. Follow your machine manual and pattern, and take care with rotary cutters, hot irons and needles. As an Amazon Associate we earn from qualifying purchases.