The picks
Best Size J Crochet Hook
Six millimeters on two brands, 5.75 on a third - and the last size before the gripped sets give up entirely.
By Sawyer V. · Published November 5, 2026
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The short answer
Size J is 6mm - on Clover and on Susan Bates, both of which print it. On Boye it is 5.75mm, printed on that company's own package. Two brands against one is the useful shape of that disagreement: these are two different ladders of millimeters sharing one set of letters, not a coin flip, so buy on the millimeter and treat the letter as a label. J matters for a second reason too: it is the largest hook most gripped sets contain. Clover's Amour range runs from 2.25mm to exactly this size and then jumps to 10mm, which is why a chunky project so often means buying a second brand. For one 6mm hook, the Clover Amour at article 1049/J is the sensible default.
| # | Product | Best for | Published size | Grip | Price |
|---|---|---|---|---|---|
| 1 | Clover Amour Crochet Hook, J-10 (6.0mm)The largest hook Clover makes in the Amour range, bought on its own - gripped, and printed with both the letter and the millimeter. | One 6mm hook for drapey worsted and bulky | J, 6.0mm (Clover) | Elastomer | $8.83 - View on Amazon#ad disclosure - price as of November 5, 2026 |
| 2 |  Susan Bates Silvalume Crochet Hook, J-10 (6mm)A bare in-line aluminum hook at 6mm for less than any other pick, and a second brand confirming that J means 6mm. | Checking whether an in-line head suits you at this size | J, 6mm (Susan Bates) | None | $6.99 - View on Amazon#ad disclosure - price as of November 5, 2026 |
| 3 |  Tulip ETIMO Red Crochet Hook, 10/0 (6.00mm)The cushioned Japanese hook at 6mm - from the Red line, because the Rose range this site lists elsewhere stops below this size. | Long sessions, and anyone who finds the Amour grip too firm | 10/0, 6.00mm (Tulip) | Cushioned | $13.65 - View on Amazon |
| 4 |  Lantern Moon Ebony Crochet Hook, J (6mm)A single ebony hook at 6mm, where a wooden surface earns its place on exactly the yarns this size suits. | Slippery yarn at a loose gauge | J, 6mm (Lantern Moon) | None - bare ebony | $15.49 - View on Amazon#ad disclosure - price as of November 5, 2026 |
| 5 |  Clover Amour Crochet Hook SetTen gripped hooks ending exactly here - J is the largest in the box, which is the useful thing to know before buying it. | Anyone crocheting across more than one yarn weight | B/2.25mm to J/6.0mm | Elastomer | $49.99 - View on Amazon#ad disclosure - price as of November 5, 2026 |
| 6 |  Boye Ergonomic Crochet Hook Set, Medium and Bulky Yarn (40-40045)A good set that picks up where the Amour stops - and whose J is 5.75mm, not 6mm. | The sizes above J, where it is genuinely useful | J, 5.75mm (Boye) | Molded grip | $16.32 - View on Amazon#ad disclosure - price as of November 5, 2026 |
Clover Amour Crochet Hook, J-10 (6.0mm)
Clover · Best for one 6mm hook for drapey worsted and bulky
The largest hook in the Amour range, sold on its own - and the size above which Clover's gripped line simply stops.
- Size
- J-10 - Clover publishes 6.0mm
- Grip
- Elastomer rubber, latex free
- Shaft
- Aluminum
- Head
- Rounded, between inline and tapered
- Sold as
- One hook, one size
- Article
- 1049/J
Who it suits
Anyone whose pattern names 6mm or J-10, anyone crocheting a garment in worsted at a loose gauge, and anyone whose Amour set has lost its biggest hook.
Why it is here
Clover sells this as article 1049/J, Size J, 6.0mm, with the molded elastomer grip and the rounded head used across the Amour line. Two things make it the default here. It is the only one of these four that prints both numbering systems on the package, which matters more at J than at the finer sizes because this is a letter brands disagree about. And it is the top of the Amour range - if you own the set and lose this hook, this is the exact replacement rather than an approximation.
What you give up
The Amour range stops here, so if you find yourself wanting a K or an L you are shopping a different brand entirely. Rubber grips also perish over years in a way bare aluminum does not.
Specifications from Clover 1049/J Amour crochet hook, Size J 6.0mm - retail listing. We have not handled this item - see how we pick.
Susan Bates Silvalume Crochet Hook, J-10 (6mm)
Susan Bates · Best for checking whether an in-line head suits you at this size
The bare in-line aluminum hook at 6mm, and the cheapest confirmation that J means 6mm on more than one brand's scale.
- Size
- J (6mm), per the listing
- Length
- 5.5in
- Head
- In-line (head sits flush with the shaft)
- Material
- Anodized aluminum, heat treated and polished
- Grip
- None - bare shaft
- Sold as
- One hook, one size
Who it suits
Anyone who crochets tightly, anyone on a budget, and anyone who wants a spare of the size they use most for blankets.
Why it is here
Listed as Size J (6mm), 5.5in, anodized aluminum that is heat treated and polished, with Susan Bates' in-line head - the hook sits flush with the shaft rather than projecting past it. In-line is the geometry that slides into a tight stitch without a wider shoulder to force through. It is also the cheapest hook on this page by a clear margin, which makes it the sensible second copy for a long blanket where losing your hook mid-project is a real risk.
What you give up
No grip at all - a bare 5.5in shaft, and 6mm is a size people use for blankets, which are the longest sittings in the craft. That combination is how hands end up aching.
Specifications from Susan Bates Silvalume crochet hook 5.5in, size J (6mm) - retail listing. We have not handled this item - see how we pick.
Tulip ETIMO Red Crochet Hook, 10/0 (6.00mm)
Tulip · Best for long sessions, and anyone who finds the amour grip too firm
The cushioned Japanese hook at 6mm - from the Red line rather than the Rose, because the Rose range stops below it.
- Size
- 6.00mm - sold as Japanese size 10/0
- Grip
- Cushioned grip
- Line
- ETIMO Red - a separate line from the ETIMO Rose this site lists elsewhere
- Sold as
- One hook, one size
Who it suits
Anyone who already knows a soft grip helps, and anyone crocheting a blanket over weeks rather than days.
Why it is here
Sold as size 10/6.00mm - 6mm on the Japanese 10/0 numbering - with a cushioned grip. Worth being precise about the line: Tulip's ETIMO Rose, which this site recommends at [G](/crochet-hooks/best-size-g-crochet-hook) and [H](/crochet-hooks/best-size-h-crochet-hook), tops out at 6.00mm in its set but is not what this single is. This is the ETIMO Red, a separate line with its own grip. If you have a Rose and like it, this is adjacent rather than identical.
What you give up
Half as much again as the Clover for a grip difference that is a preference, not an upgrade. And because it carries no US letter anywhere on it, it is easy to buy the wrong size shopping by number.
Specifications from Tulip Etimo Red crochet hook with cushion grip, size 10/6.00mm - retail listing. We have not handled this item - see how we pick.
Lantern Moon Ebony Crochet Hook, J (6mm)
Lantern Moon · Best for slippery yarn at a loose gauge
A single ebony hook at 6mm - the wooden option at the size where worsted starts to drape.
- Size
- US J (6mm)
- Material
- Ebony wood
- Format
- Single ended
- Sold as
- One hook, one size
Who it suits
Anyone working a drapey worsted - mercerized cotton, bamboo blends, silk - where stitches slide off aluminum.
Why it is here
Ebony, single ended, listed as US size J (6mm). Six millimeters is where worsted stops being structural and starts to drape, and the yarns people reach for to get that drape are the slick ones. Wood holds a loop where metal lets it travel, which matters more as the stitches get bigger and looser. It is also the only pick here that is a pleasant object in its own right.
What you give up
Twice the Clover for a hook with no grip - the shaft is the handle, so it does nothing for tired hands on a long blanket. Wood also wants keeping dry; never wash it. [Best wooden crochet hooks](/crochet-hooks/best-wooden-crochet-hooks) covers the category.
Specifications from Lantern Moon ebony single-ended crochet hook, US size J (6mm) - retail listing. We have not handled this item - see how we pick.
Clover Amour Crochet Hook Set
Clover · Best for anyone crocheting across more than one yarn weight
Ten aluminum hooks with a molded elastomer grip, covering 2.25mm to 6.0mm - the whole span most patterns for worsted and DK yarn ever ask for.
- Sizes
- 10 hooks: B/2.25mm to J/6.0mm
- Grip
- Elastomer rubber, latex free
- Shaft
- Aluminum
- Head
- Rounded, between inline and tapered
- Color coding
- Handle color differs per size
Who it suits
Anyone who works DK and worsted both, and anyone replacing a mixed-brand collection with one scale.
Why it is here
Ten hooks, B/2.25mm to J/6.0mm, elastomer grip, rounded head, color coded by size. Buying the set also sidesteps the problem at the top of this page: every hook in it is a Clover on one ladder, so a G really is 4.0mm and a J really is 6.0mm. The break-even against single gripped hooks lands around five sizes, which most crocheters pass inside a year.
What you give up
It stops at J. Clover's next gripped offering is the Amour jumbo set at 10, 12 and 15mm, so there is nothing from this range between 6mm and 10mm - the K and L sizes a chunky blanket wants are a different purchase from a different maker.
Specifications from Clover USA product page. We have not handled this item - see how we pick.
Boye Ergonomic Crochet Hook Set, Medium and Bulky Yarn (40-40045)
Boye · Best for the sizes above j, where it is genuinely useful
The same tapered Boye throat in the four sizes chunky and blanket yarn actually use, which the light set stops well short of.
- Head
- Tapered throat with a rounded head
- Set contents
- 4 hooks: J/5.75mm, K/6.5mm, L/8mm, N/10mm
- Suits
- Medium and bulky weight yarn, per the model name
- Shaft
- Anodized aluminum
- Handle
- Molded ergonomic grip, color-coded by size
- Model
- 40-40045
Who it suits
Nobody who came here needing a 6mm hook specifically.
Why it is here
Boye's own package for the 40-40045 set prints its sizes as US J / 5.75mm, US K / 6.5mm, US L / 8mm and US N / 10mm. That J is a quarter of a millimeter under Clover's and Susan Bates', which both publish 6mm - so if a pattern says 6mm and you reach for this set's J, you are a size off before you start. The set is otherwise the obvious answer to the gap the Amour leaves above 6mm, which is exactly why it is worth knowing what its J really is.
What you give up
Buy it for the K, L and N, which are the sizes almost nothing else in this price range covers with a grip. Just do not buy it for the J, and if you already own one, measure before you swatch.
Specifications from Michaels - Boye Ergonomic Aluminum Crochet Hook Set, sizes J/K/L/N. We have not handled this item - see how we pick.
Three brands, three ladders
This site has now checked four letters against the makers' own published figures, and the pattern is clear enough to act on: the US letter is a label, not a measurement.
| Letter | Clover | Susan Bates | Boye | Agree? |
|---|---|---|---|---|
| G | 4.0mm | Not published as a single | 4.25mm | No |
| H | 5.0mm | 5.0mm | 5mm | Yes |
| I | 5.5mm | Not published as a single | 5.25mm | No |
| J | 6.0mm | 6mm | 5.75mm | No - two against one |
J is the first of these where two brands agree against a third, which makes it the clearest case. If your pattern says 6mm, a Clover J and a Susan Bates J both are; a Boye J is not. A quarter of a millimeter is roughly a third of the step between neighboring hook sizes, which is enough to miss a published gauge - and on a garment a missed gauge compounds across every row.
The size where the sets stop
This is the second thing worth knowing about J, and it catches people out when they move from garments to blankets.
| Set | Range | Covers 6mm? |
|---|---|---|
| Clover Amour (10 hooks) | B/2.25mm to J/6.0mm | Yes - as its largest size |
| Clover Amour Jumbo (3 hooks) | 10mm, 12mm, 15mm | No - starts above the gap |
| Boye 40-40044 (4 hooks) | F/3.75mm to I/5.25mm | No - stops below |
| Boye 40-40045 (4 hooks) | J/5.75mm to N/10mm | Its J is 5.75mm, not 6mm |
Read those ranges together and a hole appears: between 6mm and 10mm, Clover's gripped line offers nothing at all, and the sizes in that gap - K at 6.5mm, L at 8mm - are where chunky blankets live. Boye's bulky set is the obvious answer to that gap, which is the honest reason it appears on this page at all despite its J being the wrong size.
For the sizes above this one, best jumbo crochet hooks covers the genuinely large end and best hook for blanket yarn covers chenille, which is where most people meet it.
What 6mm is actually for
The yarn bands are the best evidence of what a manufacturer thinks this hook is for, and three of the yarns this site lists print J-10 outright.
| Yarn | Weight | Published hook | Published crochet gauge |
|---|---|---|---|
| Lion Brand Heartland | 4 Medium / worsted | J-10 (6mm) | 12 sc x 15 rows / 4in |
| Lion Brand Wool-Ease | 4 Medium / worsted | J-10 (6mm) | 13.2 sc x 16 rows / 4in |
| Patons Classic Wool Roving | 5 Bulky | 6mm (US J/10) | 10 sc x 11 rows / 4in |
- Worsted at its drapiest. Six millimeters is the loose end of the worsted band, which is where garments and shawls want to be - a 5mm fabric in the same yarn would stand up rather than hang.
- Blankets with drape, which is most of what gets crocheted in worsted. A looser fabric is warmer for its weight and far faster.
- Bulky yarn at a firm gauge, as Patons Classic Wool Roving's band shows - a bulky worked at 6mm comes out dense and hard-wearing.
- Granny squares, where the open structure benefits from the extra room.
- Not amigurumi. At 6mm the stuffing shows through. That is a 3.5mm to 4mm job - best crochet hooks for amigurumi covers it.
Best crochet hook for worsted weight yarn approaches the same ground from the yarn side, across the whole 5mm to 6mm band rather than this one size.
Numbering, one more time
The letter problem is not the only one. Three systems describe this hook and two of them use bare numbers that look like millimeters and are not.
| System | This hook | Notes |
|---|---|---|
| US letter | J-10 | 6.0mm on Clover and Susan Bates, 5.75mm on Boye |
| Metric | 6mm | The only figure that cannot be misread |
| Japanese | 10/0 | Tulip sells its 6mm ETIMO Red as size 10/6.00mm |
Note the collision hiding in the first row: the US system writes this size as both J and 10, and the Japanese system writes it as 10/0. A listing that says only 10 could mean either, and they happen to agree here - which they do not at every size. The crochet hook size chart has the full letter-to-millimeter table.
Single or set
An honest page about one hook has to say when one hook is the wrong purchase.
A ten-piece gripped set spans 2.25mm to 6.0mm for roughly six times the price of one gripped single, so the break-even sits around five sizes. Anyone who crochets both garments and blankets passes that quickly, and the set keeps you on one manufacturer's ladder - which, after the table at the top of this page, is worth something on its own.
Buy the single when 6mm is the size you actually use, when you want a material the set does not offer, or - most practically at this size - when you want a second copy of the hook you are crocheting a blanket with. A garment or a blanket is weeks of work at one gauge, and finishing it on a different hook is a visible mistake. Hook sets vs single hooks has the arithmetic, and best crochet hooks for garments makes the two-identical-hooks case in full.
How we picked
Ranked on published size first, because that is the thing this category gets wrong and the reason this page exists, then on grip and head profile, then on price. Every figure comes from the manufacturer's own published product information or, where a maker publishes no figure, from the retail listing that does - all cited below. We have not held or crocheted with any of these hooks and make no claim about how they feel. How we pick explains the method.
Questions people actually ask
What size is a J crochet hook in mm?
6mm on most brands. Clover publishes its J as 6.0mm on article 1049/J and Susan Bates lists its J as 6mm. Boye is the exception at 5.75mm, printed on the package of its 40-40045 set. Patterns that say J almost always mean 6mm.
Is a J hook 6mm or 5.75mm?
Both exist, which is the problem. Two brands publish 6mm and one publishes 5.75mm, and none of them is wrong - the US letter scale is not standardized between manufacturers. Match the millimeter your pattern gives rather than the letter.
What is a J-10 crochet hook?
The same hook. The US system carries a letter and a number for every size and prints them together, so J, 10 and J-10 all name the same hook. Confusingly, the Japanese system also calls this size 10/0 - they agree at this size, though not at every size.
What yarn do you use with a size J crochet hook?
Worsted at its loose end and bulky at its firm end. Lion Brand Heartland and Wool-Ease both print J-10 (6mm) on the band, and Patons Classic Wool Roving - a bulky - publishes its crochet gauge on 6mm too. It is the size for garments, shawls and blankets that should drape.
Is J the biggest crochet hook in a set?
In most gripped sets, yes. Clover's ten-hook Amour set runs B/2.25mm to J/6.0mm and stops there; its next gripped offering is a jumbo set at 10, 12 and 15mm. So there is nothing in that range between 6mm and 10mm, and the K and L sizes a chunky blanket wants usually mean buying a second brand.
Should I buy a single J hook or a set?
A set if you will use three or more sizes - the break-even against gripped singles is around five, and a set keeps every hook on one manufacturer's scale. A single if 6mm is the size you actually use, or if you want a second identical hook for a long blanket, which is the most practical reason to buy one at this size.
What is the difference between a J and a K crochet hook?
Half a millimeter on most scales - J is 6mm and K is 6.5mm. The practical difference is bigger than it sounds, because that is also the point where the standard gripped sets end: Clover's Amour stops at J, so a K usually means a different set or a different brand.
Can I use a size J hook for amigurumi?
Not with the yarn it is meant for. Amigurumi has to be dense enough that stuffing does not show through, which means working several sizes tighter than the ball band - usually 3.5mm to 4mm in DK or worsted. A 6mm hook makes a fabric with visible gaps.
Sources
- Clover 1049/J Amour crochet hook, Size J 6.0mm - retail listing
- Clover 1048/I Amour crochet hook, Size I 5.5mm - retail listing
- Clover 1047/H Amour crochet hook, Size H 5.0mm - retail listing
- Clover 1045/G Amour crochet hook, Size G 4.0mm - retail listing
- Clover USA - Amour crochet hook set
- Clover USA - Amour crochet hook P/Q (15mm), the range the jumbo set is drawn from
- Susan Bates Silvalume crochet hook 5.5in, size J (6mm) - retail listing
- Boye 40-40045 ergonomic hook set, sizes J/K/L/N - retail listing
- Boye 40-40044 ergonomic hook set, sizes F/G/H/I - retail listing
- Tulip Etimo Red crochet hook with cushion grip, size 10/6.00mm - retail listing
- Lantern Moon ebony single-ended crochet hook, US size J (6mm) - retail listing
- Lion Brand - Heartland specification
- Lion Brand - Wool-Ease specification
- Yarnspirations - Patons Classic Wool Roving specification