# Luer connectors (ISO 594 / ISO 80369-7): 6% taper dimensions, male and female Luer slip and Luer lock, + true-size taper gauges

> What are the dimensions of a Luer taper, male tip diameter, female opening, taper length and Luer lock thread?

- Category: Tri-clamp & pipe › Pipe, tube & threads
- Kind: Standard part
- Basis: ISO 594-1:1986 Table 1 (copy), the iTeh sample pages and Thread Check's table for ISO 594-2 lock fittings, and a gauge maker's summary of ISO 80369-7:2016 vs 2021; three taper gauges as files
- Page: https://xemstudio.com/objects/luer-connectors-iso-594-80369-7/ · JSON: https://xemstudio.com/api/geometry?object=luer-connectors-iso-594-80369-7 · Plain text: https://xemstudio.com/objects/luer-connectors-iso-594-80369-7/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 16.0 | 16.0 | 9.5 |

**Exact dimensions.** Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part.

## Notes

- A Luer taper is a 6 % conical fitting: the diameter grows by 0.06 mm for every mm of length (0.06:1; a 6 % taper, not a six-degree cone). ISO 594-1:1986 gives, for a male fitting, the reference diameter d min 3.925 mm at the end (d max 3.990 mm rigid, 4.027 mm semi-rigid) and a length E of at least 7.5 mm; for a female fitting, the opening diameter D 4.270 to 4.315 mm and a depth F of at least 7.5 mm. ISO 594-1 has been replaced for new designs by ISO 80369-7 (small-bore connectors for intravascular or hypodermic use) which restates the male and female limits at other measuring planes; the limits are in the table as a gauge maker lists them. The copy of ISO 594-1 read is garbled in the tolerance row of the table (the letter M for the female engagement tolerance is inferred from a footnote), so the engagement tolerance rows M and N are left out.
- The 80369-7 limits are not directly comparable with the 594-1 ones, because they sit at other measuring planes: its male d is 3.970 – 4.072 mm (semi-rigid) and its female D 4.198 – 4.298 mm. The 80369-7 table is a third-party summary, not the standard; check the standard before using it for a compliance decision. The summary does not state the planes themselves.
- Luer lock (ISO 594-2): the same cone, plus a double-start right-hand thread with 2.5 mm pitch (5 mm lead) on the female (lugs or external thread) and a collar on the male. The lock dimensions in the table are the ones that agree between the iTeh sample pages (OCR) and Thread Check's table. The male thread root and crest diameters (H, J) and the outside diameter across lugs (2X) differ between the two copies (for example 2X 7.83 in one and 7.33 in the other) or are unreadable, so they are not shown. The lock thread and lug are not drawn: no profile is published as numbers in a source read.
- Files are three gauges, not syringes: (1) a male cone, Ø3.925 at the tip end growing at 6 % over 7.5 mm to Ø4.375, on a Ø10 handle; (2) a female socket with the opening at Ø4.270 (D min) closing at 6 % over 7.5 mm to Ø3.820; (3) the same socket at the opening Ø4.315 (D max, bottom Ø3.865). The cone numbers are ISO 594-1's; handle, hub, flange and the straight relief bore behind the cone are Xem's choices. A real Luer part also has a bore, a collar or a hub that this page does not define; for a syringe with its Luer tip see plastic-syringes and glass-syringes.
- Barb adapters, tube sizes: luer-to-barb-adapters. Silicone, PU and push-fit tube: silicone-tube-and-fittings. Maker CAD: Qosina publishes models of its Luer parts for registered users; linked, not copied.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| male Luer cone (files luer-male-cone-gauge) | Ø3.925 at the tip end, 6 % taper (0.06 mm per mm), 7.5 mm long to Ø4.375 (ISO 594-1 d min, E min) | female Luer socket (files luer-female-socket-gauge) or the female Luer hub of a syringe, needle hub or fitting; the cone is the fit | designed | luer-male* |
| female Luer socket (file luer-female-socket-gauge-D4p270) | opening Ø4.270 (ISO 594-1 D min), 6 % taper, 7.5 mm deep to Ø3.820 | male Luer tip of a syringe or fitting (plastic-syringes, glass-syringes) | designed | luer-female* |
| female Luer socket (file luer-female-socket-gauge-D4p315) | opening Ø4.315 (ISO 594-1 D max), 6 % taper, 7.5 mm deep to Ø3.865 | male Luer tip of a syringe or fitting; the other limit of the opening | designed | luer-female* |

## Sizes

| standard | symbol | what it is | value | unit |
|---|---|---|---|---|
| ISO 594-1:1986 (6 % taper) | d min | min diameter at the end of the male fitting (reference diameter) | 3.925 (rigid and semi-rigid) | mm |
| ISO 594-1:1986 | d max | max diameter at the end of the male fitting | 3.990 rigid; 4.027 semi-rigid | mm |
| ISO 594-1:1986 | D min / max | diameter at the opening of the female fitting | 4.270 / 4.315 | mm |
| ISO 594-1:1986 | E min | length of the male fitting | 7.500 | mm |
| ISO 594-1:1986 | F min | depth of the female fitting | 7.500 | mm |
| ISO 594-1:1986 | L min | length of engagement (derived from the basic dimensions per the standard's footnote) | 4.665 rigid; 4.050 semi-rigid | mm |
| ISO 594-1:1986 | R max | radius of curvature at the end (or an equivalent entry chamfer, no sharp corners) | 0.5 | mm |
| ISO 594-1:1986 | taper | gauges drawn at 0.06:1 | 6 % (0.06 mm of diameter per mm of length; not a 6-degree cone) | — |
| ISO 80369-7 (2016 and 2021) | male d, semi-rigid | limits as listed by a gauge maker | 3.970 – 4.072 | mm |
| ISO 80369-7 (2021) | male d, rigid | limits (new in the 2021 edition) | 3.970 – 4.035 | mm |
| ISO 80369-7 (2021) | male g, semi-rigid / rigid | limits (2016 semi-rigid: 4.376 – 4.476) | 4.375 – 4.477 / 4.375 – 4.440 | mm |
| ISO 80369-7 (2021) | female D, semi-rigid | limits (recommended 4.225 – 4.298; 2016: 4.198 – 4.298) | 4.198 – 4.298 | mm |
| ISO 80369-7 (2021) | female D, rigid | limits (same as the ISO 594 range) | 4.225 – 4.270 | mm |
| ISO 80369-7 (2021) | female G, semi-rigid / rigid | limits (recommended semi-rigid 3.820 – 3.893; 2016: 3.793 – 3.893) | 3.793 – 3.893 / 3.820 – 3.865 | mm |
| ISO 80369-7 reference connectors (2021) | male cone SE diameter, angle | reference connector cone, at 0.75 mm | 4.021 +0.001/−0.004; 3.437° | mm |
| ISO 80369-7 reference connectors (2021) | female cone LE diameter, angle | reference connector cone, at 0.75 mm | 4.247 +0.001/−0.004; 3.436° | mm |
| ISO 594-2 (lock) | thread | female lock thread: double-start, right-hand, nominal pitch 2.5 mm | lead 5 | mm |
| ISO 594-2 (lock) | E min | length of male lock fitting | 7.5 | mm |
| ISO 594-2 (lock) | G max | female outside diameter at the lug base / internal thread diameter | 6.73 | mm |
| ISO 594-2 (lock) | K max | male thread width at root | 1.0 | mm |
| ISO 594-2 (lock) | P min | projection of the nozzle from the collar | 2.1 | mm |
| ISO 594-2 (lock) | Q min | male thread crest width | 0.3 | mm |
| ISO 594-2 (lock) | S min | female lug / thread crest width | 0.3 | mm |
| ISO 594-2 (lock) | T max | male tip to bottom of the first complete internal thread form (the 80369-7 reference connector also shows 3.2) | 3.2 | mm |
| ISO 594-2 (lock) | V max | female lug chord at the base, on a circle of Ø7.0 min | 3.5 | mm |
| ISO 594-2 (lock) | W min | female lug chord at the extremity | 2.71 | mm |
| ISO 594-2 (lock) | Y max | lug / thread base width, at G max | 1.2 | mm |
| ISO 594-2 (lock) | α | thread / lug bearing surface angle to the plane at right angles to the axis | 25° +5′/0 (one copy: +5°/−0) | — |
| ISO 594-2 (lock) | H, J, 2X | male thread root diameter, crest diameter, outside diameter across lugs | sources disagree or unreadable: not shown | — |

## Where the files are

- ISO 594-1:1986 (copy hosted by mdcpp.com): [ISO 594-1: Conical fittings with a 6% (Luer) taper for syringes, needles and certain other medical equipment, Part 1: General requirements; Table 1 dimensions d, D, E, F, L, R](https://mdcpp.com/doc/standard/ISO594-1-1986(E).pdf) — web — Copy of the standard; numbers only
- iTeh Standards (ISO 594-2:1991 sample pages): [ISO 594-2: Lock fittings, Part 2: dimensions of rigid conical lock fittings (table 1 symbols), sample pages (OCR text, partly garbled)](https://cdn.standards.iteh.ai/samples/4694/bf4ef10b987d42e18fa32a6099c9e15d/ISO-594-2-1991.pdf) — web — Sample pages; numbers only
- Thread Check: [ISO 594-2 technical info: lock-fitting dimension table (text is partly garbled)](https://www.threadcheck.com/iso-594-2/technicalinfo/) — web — Gauge maker's page; numbers only
- Ring & Plug Thread Gages: [ISO 80369-7 changes 2016 to 2021: male d, g and female D, G limits (rigid and semi-rigid), reference connector dimensions (third-party summary)](https://ring-plug-thread-gages.com/ti-spec-ISO-80369-7-Changes-2016-to-2021.html) — web — Gauge maker's summary; numbers only, check the standard
- Wikipedia: [Luer taper](https://en.wikipedia.org/wiki/Luer_taper) — web — CC BY-SA 4.0 (text)
- Qosina: [Luer connectors and fittings (maker's own CAD models after free log-in)](https://www.qosina.com/pc-luer-lock-to-barb-connector-sample-kit-q3000-pc) — web — Maker's page; CAD behind a free log-in, not copied

## Free STEP/STL (3 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/index.json

- luer-male-cone-gauge-d3p925-6pct: [STEP](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-male-cone-gauge-d3p925-6pct.step) · [STL](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-male-cone-gauge-d3p925-6pct.stl) — male Luer cone gauge: Ø3.925 at the tip end (ISO 594-1 d min, the reference diameter), 6 % taper (0.06 mm of diameter per mm), E = 7.5 mm long, so Ø4.375 where the cone meets the handle; then a plain Ø10 × 12 mm handle (handle size is Xem's choice). Tip chamfer / radius R 0.5 max is not drawn
- luer-female-socket-gauge-D4p270-6pct: [STEP](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-female-socket-gauge-D4p270-6pct.step) · [STL](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-female-socket-gauge-D4p270-6pct.stl) — female Luer socket gauge: opening Ø4.27 (ISO 594-1 D min), 6 % taper, F = 7.5 mm deep, so Ø3.82 at the bottom; Ø10 hub, Ø16 × 2 flange behind it and a straight Ø3.82 relief bore through the flange (hub, flange and relief bore are Xem choices; the depth is the standard's minimum F)
- luer-female-socket-gauge-D4p315-6pct: [STEP](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-female-socket-gauge-D4p315-6pct.step) · [STL](https://xemstudio.com/files/hardware/luer-connectors-iso-594-80369-7/luer-female-socket-gauge-D4p315-6pct.stl) — female Luer socket gauge at the other limit: opening Ø4.315 (ISO 594-1 D max), 6 % taper, 7.5 mm deep, Ø3.865 at the bottom; same hub, flange and relief bore as the D 4.270 gauge (Xem choices)

## Questions

**What is the diameter of a male Luer tip?**

ISO 594-1:1986 gives 3.925 mm minimum at the end of the male fitting (3.990 mm max rigid, 4.027 mm max semi-rigid), growing 6 % (0.06 mm per mm) along at least 7.5 mm.

**What is the female Luer opening diameter?**

4.270 mm minimum and 4.315 mm maximum at the opening in ISO 594-1, at least 7.5 mm deep, 6 % taper. ISO 80369-7:2021 lists 4.225 – 4.270 mm for rigid and 4.198 – 4.298 mm for semi-rigid female D at its own measuring plane.

**What is the Luer lock thread?**

Double-start, right-hand, 2.5 mm pitch, so a 5 mm lead (ISO 594-2). A Luer lock is a quarter-turn-class connector with lugs on the female and a threaded collar on the male.

## Fits with

- [Plastic syringes 1–60 mL as pistons and cylinders](https://xemstudio.com/objects/plastic-syringes/)
- [Glass syringes 1–50 mL (all-glass, ground-glass plunger): barrel and plunger](https://xemstudio.com/objects/glass-syringes/)
- [Silicone tube 1 × 3 to 10 × 14 mm (ID × OD)](https://xemstudio.com/objects/silicone-tube/)
- [Luer lock and Luer slip to barb adapters: tubing ID sizes 1/16 to 1/4 in (Nordson Value Plastics, Qosina), male and female](https://xemstudio.com/objects/luer-to-barb-adapters/)
- [Aquarium airline tubing and fittings: 3/16 in vs 4 × 6 mm, check valves, connectors and Luer barb match](https://xemstudio.com/objects/aquarium-airline-tubing/)
- [90° elbow for 4 × 6 mm tube](https://xemstudio.com/objects/transfer-elbow-4mm/)