The picks
Best US Size 4 Knitting Needles
Three and a half millimeters. If you own a premium set, this is the finest needle in it - and the bottom of what it can do.
By Sawyer V. · Published October 1, 2026
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The short answer
US 4 is 3.5mm, and it is the smallest size two of the three premium interchangeable sets make - both the addi Click Turbo and the Knitter's Pride Dreamz Deluxe start exactly here. If you own either, this is the finest needle in your case. Buy a 24in fixed circular if you are buying one, double points if you are knitting socks or gloves, and know that it sits a half step above the standard sock size rather than at it.
| # | Product | Best for | Format | Price |
|---|---|---|---|---|
| 1 | Clover Takumi Bamboo Circular Needle, US 4 (3.5mm), 24inA fixed bamboo circular at the size your set bottoms out at. | Owning 3.5mm without buying a set | Fixed circular | $6.66 - View on Amazon |
| 2 |  ChiaoGoo Red 6in Stainless Double Point Needles, US 4 (3.5mm)Five stainless double points that will not break at a tight gauge. | Cuffs, gloves and a looser sock fabric | Double points | $20.32 - View on Amazon#ad disclosure - price as of October 1, 2026 |
| 3 |  addi Click Turbo Interchangeable Needle SetUS 4 is where this set starts - the finest tip in the case. | Owning US 4 and everything above it | Interchangeable set | $195.08 - View on Amazon |
| 4 |  Clover Takumi Bamboo Single Point Needles, US 4 (3.5mm), 9inShort bamboo straights for less than a ball of decent sock yarn. | One small flat project | Straights | $5.75 - View on Amazon#ad disclosure - price as of October 1, 2026 |
| 5 |  Bernat BlanketSuper bulky chenille on a 3.5mm needle is not a fabric. | Blankets on an 8mm hook or needle | Yarn | $20.96 - View on Amazon#ad disclosure - price as of October 1, 2026 |
Clover Takumi Bamboo Circular Needle, US 4 (3.5mm), 24in
Clover · Best for owning 3.5mm without buying a set
Bamboo at the size two interchangeable sets stop at, on the cable length that covers the most projects.
- Size
- US 4 (3.5mm)
- Cable length
- 24in (61cm)
- Material
- Bamboo tips, flexible soft cord
- Point
- Tapered
- Article no.
- 3016/24-4
- Sold as
- Fixed circular, one size and length per pack
Who it suits
Anyone with a sport-weight pattern, or a sock pattern they knit too tightly.
Why it is here
US 4 (3.5mm) bamboo tips on a flexible soft cord, 24in, article 3016/24-4. Twenty-four inches is the general-purpose length - it knits flat, holds a sweater body and does magic loop - and bamboo grips, which matters at a gauge this fine with slippery superwash sock yarn.
What you give up
One size and one length per pack. Bamboo at 3.5mm is also genuinely thin and will snap under a tight sock gauge or if you sit on it, which is the argument for steel at this end of the scale.
Specifications from Clover USA - Takumi bamboo circular needles. We have not handled this item - see how we pick.
ChiaoGoo Red 6in Stainless Double Point Needles, US 4 (3.5mm)
ChiaoGoo · Best for cuffs, gloves and a looser sock fabric
Five stainless double points at 3.5mm - a half step up from the standard sock size, for tight knitters and thicker sock yarn.
- Size
- US 4 (3.5mm)
- Material
- Stainless steel, precisely machined
- Length
- 6in (15cm)
- Pack
- Five needles
- Point and finish
- Tapered points, satin finish
- Marking
- Size laser etched on every needle
Who it suits
Anyone whose socks come out too dense on a US 3.
Why it is here
Five 6in stainless steel double points at US 4 (3.5mm), precisely machined, with tapered points, a satin finish and the size laser etched on every needle. Etched sizing matters more in this part of the scale than anywhere else, because 3.25mm, 3.5mm and 3.75mm needles are indistinguishable by eye.
What you give up
Five loose needles to keep track of, and steel is slick enough that stitches slide off the idle ones when you put the work down. It is also the most expensive thing on this page.
Specifications from ChiaoGoo 6in stainless double point needles - retail specification. We have not handled this item - see how we pick.
addi Click Turbo Interchangeable Needle Set
addi · Best for owning us 4 and everything above it
Ten pairs of blunt-tipped nickel-plated tips joined by a twist-and-click mechanism instead of a screw thread.
- Tips
- 10 pairs, 5in, US 4-15 (3.5-10mm)
- Tip finish
- Nickel plated, Turbo (blunt) point
- Join
- Twist-and-click locking mechanism, no key needed
- Cords
- 3 cords making 24in, 32in and 40in circulars
- Also included
- Click connector and addiGrip tip handle
Who it suits
Anyone buying a set who does not intend to knit socks at the standard size.
Why it is here
Ten pairs of 5in nickel-plated tips covering US 4 to 15 (3.5-10mm), with a twist-and-click join that needs no key and cords making 24in, 32in and 40in circulars. If you own this set you already own US 4, and you own nothing below it.
What you give up
That floor is the point: the set cannot make US 1 to 3, which is where most American sock patterns live. The Turbo tips are also blunt, which suits plain knitting and fights you on a tight decrease.
Specifications from addi Click Turbo set specification. We have not handled this item - see how we pick.
Clover Takumi Bamboo Single Point Needles, US 4 (3.5mm), 9in
Clover · Best for one small flat project
Short bamboo straights at 3.5mm - the cheapest way to own this size, in the length that suits small flat pieces.
- Size
- US 4 (3.5mm)
- Length
- 9in
- Material
- Bamboo
- Point
- Tapered
- Sold as
- A pair, one size per pack
- Format
- Single point - flat knitting only
Who it suits
Anyone who needs 3.5mm once and knits flat.
Why it is here
A pair of 9in bamboo single points at US 4 (3.5mm), tapered, from the same Takumi line as the circular above. Nine inches is short for straights, which suits the small flat pieces this size is usually used for rather than a wide shawl.
What you give up
Straights cannot knit in the round, which rules out the socks, cuffs and gloves US 4 is most often bought for. Nine inches also caps the stitch count fairly low.
Specifications from Clover USA - Takumi bamboo single point needles. We have not handled this item - see how we pick.
Bernat Blanket
Bernat · Best for blankets on an 8mm hook or needle
Polyester chenille at 108 yards to a 150g ball. Fast, warm, machine washable, and it will shed and worm if the tension is loose.
- Fiber
- 100% polyester (chenille)
- Weight
- 6 Super Bulky
- Ball
- 5.3oz / 150g, 108yd / 98m
- Gauge
- 8 sts x 13 rows on 8mm (US 11)
- Hook
- 8mm (US L/11), 7 sc x 8 rows
- Care
- Machine wash delicate, tumble dry gentle
Who it suits
Not US 4 knitters. On the needle its band names it makes a genuinely soft blanket.
Why it is here
100% polyester chenille, category 6 super bulky, 108yd per 150g ball, published at 8 stitches and 13 rows over 4in on an 8mm (US 11) needle.
What you give up
Its own band asks for a needle more than twice this diameter. Forced onto a US 4 the stitches will not form at all, and the chenille pile shreds against a fine tip. See [best yarn for a blanket](/yarn-by-project/best-yarn-for-a-blanket) for where it belongs.
Specifications from Yarnspirations product page. We have not handled this item - see how we pick.
The size your set bottoms out at
This site has twice had to point out that interchangeable sets stop short at the fine end. US 4 is where two of them stop.
| Set | Smallest tip | US 4 included? |
|---|---|---|
| addi Click Turbo | US 4 (3.5mm) | Yes - it is the smallest |
| Knitter's Pride Dreamz Deluxe | US 4 (3.5mm) | Yes - it is the smallest |
| ChiaoGoo TWIST Red Lace Complete | US 2 (2.75mm) | Yes, with two sizes below it |
That makes this page unusual. For most sizes the question is which needle to buy; here, a large share of readers already own one and do not realize it. Check the case before you spend anything.
The sock question
Most American sock patterns are written for US 1 to 3 - 2.25mm to 3.25mm. US 4 is a half step above that, and sock knitters arrive here for two specific reasons.
- You knit tightly. If a US 3 gives you a fabric like cardboard and sore hands, going up a quarter millimeter is the fix. You are matching the fabric, not the pattern's tool.
- The yarn is thicker than standard fingering. Sport-weight sock yarn and some heavier 4-ply want more room than 3.25mm gives.
- You want a faster, softer sock and accept it will wear through sooner. A looser sock fabric is less hard-wearing - that is the trade.
- Not: because the pattern said so. If a pattern names US 4 for socks it usually also names a thicker yarn.
Best US size 3 knitting needles covers the standard sock size, and best yarn for socks the yarn side.
What else 3.5mm is for
- Sport weight, which the standard weight system puts at 3.25-3.75mm - US 4 is the middle of that band.
- Baby garments, where sport and fine DK dominate.
- Gloves and mittens, which want a denser fabric than a sweater.
- Ribbing on a DK sweater, worked a size or two below the body so the cuffs grip.
- Colorwork at sport weight, though many knitters go up rather than down because stranding tightens the fabric.
The quarter-millimeter run
Between US 3 and US 6 the scale steps in quarter millimeters, finer resolution than anywhere else in common use. Four adjacent sizes, all of which look identical in the hand.
| US size | Metric | Usually used for |
|---|---|---|
| US 3 | 3.25mm | The standard sock size |
| US 4 | 3.5mm | Sport weight, looser socks |
| US 5 | 3.75mm | Sport and DK worked tightly |
| US 6 | 4mm | The standard DK size |
- You cannot tell these apart by eye. A needle gauge settles it in seconds and is the cheapest tool on this site.
- Buy on the millimeter figure. US numbers vary slightly between brands, and the metric one does not.
- A quarter millimeter is small per inch and a whole size across a garment, which is why swatching matters more here than at chunky weights.
Full conversions are on the needle size chart, and the yarn bands on the yarn weight chart.
Bamboo or steel at this size
This is the point on the scale where the material choice starts to carry real consequences rather than being a preference.
- Steel will not break. At 3.5mm, under the tension sock knitting uses, that stops being theoretical.
- Bamboo grips, which helps with slippery superwash sock yarn and with stitches sliding off double points.
- Sharp points help with the tight decreases a sock heel needs; blunt tips fight you there.
- Bamboo is warmer in the hand and quieter, which some people care about a great deal.
- Neither is wrong yet. By 2mm wood genuinely starts to fail - see best US size 0 knitting needles - but at 3.5mm both are viable.
Bamboo vs metal knitting needles works through the trade in full.
How we picked
Every needle on this page is a listing for US 4 (3.5mm) specifically, not a product line that happens to include the size. Needle listings are one size per pack, so a link to the right product in the wrong size sends you something you cannot use. The set ranges are the manufacturers' published tip ranges and the yarn bands come from the standard weight system. We have not knitted with any of these; this site does not test products and says so on every page.
What we would buy
- Check your set first - if you own an addi Click or a Dreamz Deluxe, you already have this size.
- One needle: a 24in bamboo circular.
- Socks, gloves and cuffs: five stainless double points.
- Buying the set: the one that starts here.
- Cheapest, flat knitting only: 9in bamboo straights.
- Not on a US 4: super bulky chenille.
Questions people actually ask
What size is a US 4 knitting needle in mm?
3.5mm. It sits between US 3 (3.25mm) and US 5 (3.75mm) - the scale steps in quarter millimeters through this range, so the three are indistinguishable by eye and a needle gauge is worth owning.
Does my interchangeable set include US 4?
If it is an addi Click Turbo or a Knitter's Pride Dreamz Deluxe, yes - US 4 is the smallest tip in both. The ChiaoGoo TWIST set reaches two sizes further down, to US 2 (2.75mm).
Can you knit socks on US 4 needles?
Yes, though most American sock patterns are written for US 1 to 3. Knitters move up to US 4 when a US 3 gives them a fabric that is too dense, or when the sock yarn is thicker than standard fingering. A looser sock fabric wears through sooner.
What weight yarn uses US 4 needles?
Sport weight, mainly - the standard weight system puts category 2 fine at 3.25-3.75mm, and US 4 is the middle of that band. It is also used for fingering knitted loosely and for ribbing on a DK garment.
Why do interchangeable sets stop at US 4?
Because the tip has to contain a threaded or clicking socket, and below about 3.5mm there is not enough metal around it to make a reliable join. It is an engineering limit rather than a cost saving.
Sources
- Craft Yarn Council - Standard Yarn Weight System
- Clover USA - Takumi bamboo circular needles
- ChiaoGoo 6in stainless double point needles - retail specification
- addiClick Turbo interchangeable needle set - retail specification
- KnitPro / Knitter's Pride Dreamz Deluxe interchangeable set - retail specification
- ChiaoGoo TWIST Red Lace set specification
- Yarnspirations - Patons Kroy Socks specification
- Yarnspirations - Bernat Blanket specification
- Susan Bates Knit-Chek 14099 - retail specification