Birmingham gauge

Last updated October 14, 2023

The Birmingham gauge^[1] is a wire gauge system, and is also used to specify thickness or diameter of hypodermic needles and tube products.

Terminology

Birmingham gauge is also known as the Stubs Iron Wire Gauge or Birmingham Wire Gauge. It is not the same as, though similar to, the Stubs Steel Wire Gauge.

Birmingham gauge is often simply termed Gauge, with the abbreviation G.^[2] However, this should not be confused with French gauge.

System

The gauge starts at the lowest gauge number of 5Ø or 00000, corresponding to the largest size of 0.500 inches (12.7 mm), and runs to the highest gauge number of 36, corresponding to the smallest size of 0.004 inches (0.10 mm). Size steps between gauges range from 0.001 inches (0.025 mm) between high gauge numbers to 0.046 inches (1.2 mm) between the two lowest gauge numbers and do not correspond to a particular mathematical pattern, although for the most part the steps get smaller with increasing gauge number.^[3] Concerning wire and fine tubing, the gauge number is used to specify the outside diameter of the product, whereas for larger mechanical tubing the gauge number specifies the wall thickness independent of the overall size of the tube.

In medicine, the Birmingham gauge specifies the outside diameter of hypodermic needles, catheters, cannulae and suture wires. It was originally developed in early 19th-century England for use in wire manufacture, and began appearing in a medical setting in the early 20th century.

Another common needle gauge system is the French catheter scale.

Needle wire gauge was derived from the Stubs Iron Wire Gauge.

Sizes of hypodermic needles

Hypodermic needles are available in a wide variety of outer diameters described by gauge numbers. Smaller gauge numbers indicate larger outer diameters.^[4] Inner diameter depends on both gauge and wall thickness. The following chart shows nominal inner diameter and wall thickness for regular-wall needles.^[4]^[5] Thin-wall needles (not shown) have identical outer diameters but larger inner diameters for a given gauge.

Gauge, G	Nominal outer diameter		Nominal inner diameter^{[lower-alpha 1]}		Nominal wall thickness^{[lower-alpha 1]}		ISO 6009 color^[6]
Gauge, G	(inch)	(mm)	(inch)	(mm)	(inch)	(mm)	ISO 6009 color^[6]
7	0.180 ± 0.001	4.572 ± 0.025	0.150 ± 0.003	3.810 ± 0.076	0.015 ± 0.001	0.381 ± 0.025	(undefined)
8	0.165 ± 0.001	4.191 ± 0.025	0.135 ± 0.003	3.429 ± 0.076	0.015 ± 0.001	0.381 ± 0.025	(undefined)
9	0.148 ± 0.001	3.759 ± 0.025	0.118 ± 0.003	2.997 ± 0.076	0.015 ± 0.001	0.381 ± 0.025	(undefined)
10	0.134 ± 0.001	3.404 ± 0.025	0.106 ± 0.003	2.692 ± 0.076	0.014 ± 0.001	0.356 ± 0.025	Olive brown
11	0.120 ± 0.001	3.048 ± 0.025	0.094 ± 0.003	2.388 ± 0.076	0.013 ± 0.001	0.330 ± 0.025	Green-yellow
12	0.109 ± 0.001	2.769 ± 0.025	0.085 ± 0.003	2.159 ± 0.076	0.012 ± 0.001	0.305 ± 0.025	Pale blue
13	0.095 ± 0.001	2.413 ± 0.025	0.071 ± 0.003	1.803 ± 0.076	0.012 ± 0.001	0.305 ± 0.025	Purple
14	0.083 ± 0.001	2.108 ± 0.025	0.063 ± 0.003	1.600 ± 0.076	0.010 ± 0.001	0.254 ± 0.025	Pale green
15	0.0720 ± 0.0005	1.829 ± 0.013	0.0540 ± 0.0015	1.372 ± 0.038	0.0090 ± 0.0005	0.229 ± 0.013	Blue-grey
16	0.0650 ± 0.0005	1.651 ± 0.013	0.0470 ± 0.0015	1.194 ± 0.038	0.0090 ± 0.0005	0.229 ± 0.013	White
17	0.0580 ± 0.0005	1.473 ± 0.013	0.0420 ± 0.0015	1.067 ± 0.038	0.0080 ± 0.0005	0.203 ± 0.013	Red-violet
18	0.0500 ± 0.0005	1.270 ± 0.013	0.0330 ± 0.0015	0.838 ± 0.038	0.0085 ± 0.0005	0.216 ± 0.013	Pink
19	0.0420 ± 0.0005	1.067 ± 0.013	0.0270 ± 0.0015	0.686 ± 0.038	0.0075 ± 0.0005	0.191 ± 0.013	Cream
20	0.03575 ± 0.00025	0.9081 ± 0.0064	0.02375 ± 0.00075	0.603 ± 0.019	0.00600 ± 0.00025	0.1524 ± 0.0064	Yellow
21	0.03225 ± 0.00025	0.8192 ± 0.0064	0.02025 ± 0.00075	0.514 ± 0.019	0.00600 ± 0.00025	0.1524 ± 0.0064	Deep green
22	0.02825 ± 0.00025	0.7176 ± 0.0064	0.01625 ± 0.00075	0.413 ± 0.019	0.00600 ± 0.00025	0.1524 ± 0.0064	Black
22s	0.02825 ± 0.00025	0.7176 ± 0.0064	0.00600 ± 0.00075	0.152 ± 0.019	0.01110 ± 0.00025	0.2826 ± 0.0064	(undefined)
23	0.02525 ± 0.00025	0.6414 ± 0.0064	0.01325 ± 0.00075	0.337 ± 0.019	0.00600 ± 0.00025	0.1524 ± 0.0064	Deep blue
24	0.02225 ± 0.00025	0.5652 ± 0.0064	0.01225 ± 0.00075	0.311 ± 0.019	0.00500 ± 0.00025	0.1270 ± 0.0064	Medium purple
25	0.02025 ± 0.00025	0.5144 ± 0.0064	0.01025 ± 0.00075	0.260 ± 0.019	0.00500 ± 0.00025	0.1270 ± 0.0064	Orange
26	0.01825 ± 0.00025	0.4636 ± 0.0064	0.01025 ± 0.00075	0.260 ± 0.019	0.00400 ± 0.00025	0.1016 ± 0.0064	Brown
26s	0.01865 ± 0.00025	0.4737 ± 0.0064	0.00500 ± 0.00075	0.127 ± 0.019	0.00680 ± 0.00025	0.1734 ± 0.0064	(undefined)
27	0.01625 ± 0.00025	0.4128 ± 0.0064	0.00825 ± 0.00075	0.210 ± 0.019	0.00400 ± 0.00025	0.1016 ± 0.0064	Medium grey
28	0.01425 ± 0.00025	0.3620 ± 0.0064	0.00725 ± 0.00075	0.184 ± 0.019	0.00350 ± 0.00025	0.0889 ± 0.0064	Blue-green
29	0.01325 ± 0.00025	0.3366 ± 0.0064	0.00725 ± 0.00075	0.184 ± 0.019	0.00300 ± 0.00025	0.0762 ± 0.0064	Red
30	0.01225 ± 0.00025	0.3112 ± 0.0064	0.00625 ± 0.00075	0.159 ± 0.019	0.00300 ± 0.00025	0.0762 ± 0.0064	Yellow
31	0.01025 ± 0.00025	0.2604 ± 0.0064	0.00525 ± 0.00075	0.133 ± 0.019	0.00250 ± 0.00025	0.0635 ± 0.0064	White
32	0.00925 ± 0.00025	0.2350 ± 0.0064	0.00425 ± 0.00075	0.108 ± 0.019	0.00250 ± 0.00025	0.0635 ± 0.0064	Deep green
33	0.00825 ± 0.00025	0.2096 ± 0.0064	0.00425 ± 0.00075	0.108 ± 0.019	0.00200 ± 0.00025	0.0508 ± 0.0064	Black
34	0.00725 ± 0.00025	0.1842 ± 0.0064	0.00325 ± 0.00075	0.0826 ± 0.019	0.00200 ± 0.00025	0.0508 ± 0.0064	Orange
1 2 Not strictly defined, and may vary for a given gauge.

Six hypodermic needles on Luer connectors. These needles are normally used with other medical devices, such as a syringe; from top to bottom:
26G x
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1/2'' (0.45 x 12 mm) (brown)
25G x
5/8'' (0.5 x 16 mm) (orange)
22G x
1+1/4'' (0.7 x 30 mm) (black)
21G x
1+1/2'' (0.8 x 40 mm) (green)
20G x
1+1/2'' (0.9 x 40 mm) (yellow)
19G x
1+1/2'' (1.1 x 40 mm) (cream) HypodermicNeedles.jpg — Six hypodermic needles on Luer connectors. These needles are normally used with other medical devices, such as a syringe; from top to bottom:
26G × 1⁄2″ (0.45 × 12 mm) (brown)
25G × 5⁄8″ (0.5 × 16 mm) (orange)
22G × 1+1⁄4″ (0.7 × 30 mm) (black)
21G × 1+1⁄2″ (0.8 × 40 mm) (green)
20G × 1+1⁄2″ (0.9 × 40 mm) (yellow)
19G × 1+1⁄2″ (1.1 × 40 mm) (cream)

Rapid blood transfusion through 23G or smaller needles can cause hemolysis (rupturing of red blood cells).^[7]

Sizes of catheters

This includes peripheral venous catheters. The gauge compared to outer diameter is the same as for needles, but the color coding is different.

Gauge	Outer diameter (mm)	Maximum flow rate (ml/min)	Color
14	2.0	250–300	Orange
16	1.7	180	Grey
18	1.3	75–120^[8]	Green^[8]
20	1.1	40–80^[8]	Pink^[8]
22	0.9	42-55^[8]	Blue^[8]
24	0.7	20-35^[8]	Yellow^[8]
26	0.6	10-13^[8]	Black^[8]

Related Research Articles

A syringe is a simple reciprocating pump consisting of a plunger that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside of the tube, allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front (open) end of the tube. The open end of the syringe may be fitted with a hypodermic needle, a nozzle or tubing to direct the flow into and out of the barrel. Syringes are frequently used in clinical medicine to administer injections, infuse intravenous therapy into the bloodstream, apply compounds such as glue or lubricant, and draw/measure liquids. There are also prefilled syringes.

Intravenous therapy is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use.

Gauge may refer to:

American Wire Gauge (AWG), also known as the Brown & Sharpe wire gauge, is a logarithmic stepped standardized wire gauge system used since 1857, predominantly in North America, for the diameters of round, solid, nonferrous, electrically conducting wire. Dimensions of the wires are given in ASTM standard B 258. The cross-sectional area of each gauge is an important factor for determining its current-carrying ampacity.

<span class="mw-page-title-main">Hypodermic needle</span> Device to inject substances into the circulatory system

A hypodermic needle, one of a category of medical tools which enter the skin, called sharps, is a very thin, hollow tube with one sharp tip. It is commonly used with a syringe, a hand-operated device with a plunger, to inject substances into the body or extract fluids from the body. Large-bore hypodermic intervention is especially useful in catastrophic blood loss or treating shock.

A cannula is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or outer surfaces of a trocar needle thus extending the effective needle length by at least half the length of the original needle. Its size mainly ranges from 14 to 26 gauge. Different-sized cannula have different colours as coded.

Glass tubes are mainly cylindrical hollow-wares. Their special shape combined with the huge variety of glass types, allows the use of glass tubing in many applications. For example, laboratory glassware, lighting applications, solar thermal systems and pharmaceutical packaging to name the largest.

Wire gauge is a measurement of wire diameter. This determines the amount of electric current the wire can safely carry, as well as its electrical resistance and weight.

Ring size is a measurement used to denote the circumference of jewellery rings and smart rings.

A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipe is far stiffer per unit weight than solid members.

Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. "Nominal" refers to pipe in non-specific terms and identifies the diameter of the hole with a non-dimensional number. Specific pipe is identified by pipe diameter and another non-dimensional number for wall thickness referred to as the Schedule. NPS is often incorrectly called National Pipe Size, due to confusion with the American standard for pipe threads, "national pipe straight", which also abbreviates as "NPS". The European and international designation equivalent to NPS is DN, in which sizes are measured in millimetres, see ISO 6708. The term NB is also frequently used interchangeably with DN.

The French scale, French gauge or Charrière system is commonly used to measure the size of a catheter. It is most often abbreviated as Fr, but can often be seen abbreviated as Fg, FR or F. It may also be abbreviated as CH or Ch. However, simply gauge, G or GA generally refers to Birmingham gauge.

A winged infusion set—also known as "butterfly" or "scalp vein" set—is a device specialized for venipuncture: i.e. for accessing a superficial vein or artery for either intravenous injection or phlebotomy. It consists, from front to rear, of a hypodermic needle, two bilateral flexible "wings", flexible small-bore transparent tubing, and lastly a connector. This connector attaches to another device: e.g. syringe, vacuum tube holder/hub, or extension tubing from an infusion pump or gravity-fed infusion/transfusion bag/bottle.

The Luer taper is a standardized system of small-scale fluid fittings used for making leak-free connections between a male-taper fitting and its mating female part on medical and laboratory instruments, including hypodermic syringe tips and needles or stopcocks and needles. Currently ISO 80369 governs the Luer standards and testing methods.

British Standard Wire Gauge is a unit for denoting wire size given by BS 3737:1964. It is also known as the Imperial Wire Gauge or British Standard Gauge. Use of SWG sizes has fallen greatly in popularity, but they are still used as a measure of thickness in guitar strings and some electrical wire. Cross sectional area in square millimetres is now the more usual size measurement for wires used in electrical installation cables. The current British Standard for metallic materials such as wire and sheet is BS 6722:1986, which is a solely metric standard.

Following is a list of instruments used in the practice of anesthesia

A tube, or tubing, is a long hollow cylinder used for moving fluids or to protect electrical or optical cables and wires.

<span class="mw-page-title-main">Copper tubing</span> Type of metal tubing

Copper tubing is most often used for heating systems and as a refrigerant line in HVAC systems. Copper tubing is slowly being replaced by PEX tubing in hot and cold water applications. There are two basic types of copper tubing, soft copper and rigid copper. Copper tubing is joined using flare connection, compression connection, pressed connection, or solder. Copper offers a high level of corrosion resistance but is becoming very costly.

Joseph-Frédéric-Benoît Charrière was a Swiss-born French manufacturer of surgical instruments.

Body jewelry sizes express the thickness of an item of body jewelry, using one of several possible systems.

References

↑ Page 400 in: Steven M. Yentis, Nicholas P. Hirsch, James Ip (2013). Anaesthesia and Intensive Care A-Z E-Book: An Encyclopedia of Principles and Practice. FRCA Study Guides (5 ed.). Elsevier Health Sciences. ISBN 978-0-7020-5375-7.{{cite book}}: CS1 maint: multiple names: authors list (link)
↑ "'French', 'gauge' and millimeters". University of California, San Francisco . Archived from the original on 2017-08-18. Retrieved 2018-02-03.
↑ Machinery's Handbook 27. New York, NY: Industrial Press, Inc. 2004. p. 2520.
1 2 "Syringe Needle Gauge Chart". Sigma Aldrich. Retrieved 20 March 2012.
↑ "Hypodermic Needle Gauge Chart". Medical Tube Technology, Inc. Archived from the original on 10 October 2004. Retrieved 20 March 2012.
↑ "ISO 6009:2016 Hypodermic needles for single use -- Colour coding for identification". International Organization for Standardization . Publication date: 2016-08
↑ Miller, Michal A.; Schlueter, Annette J. (2004). "Transfusions via hand-held syringes and small-gauge needles as risk factors for hyperkalemia". Transfusion. 44 (3): 373–381. doi:10.1111/j.1537-2995.2004.00653.x. ISSN 0041-1132. PMID 14996194. S2CID 22956171.
1 2 3 4 5 6 7 8 9 10 Page 110 in: Edward Doyle (2007). Pediatric Anesthesia. OUP Oxford. ISBN 978-0-19-920279-9.

External links

Iserson KV (1987). "The origins of the gauge system for medical equipment". J Emerg Med. 5 (1): 45–8. doi:10.1016/0736-4679(87)90009-6. PMID 3295010.
Sheet Metal Gauge Size Data – Engineers Edge

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[nominal-6] 1 2 Not strictly defined, and may vary for a given gauge.

[1] Page 400 in: Steven M. Yentis, Nicholas P. Hirsch, James Ip (2013). Anaesthesia and Intensive Care A-Z E-Book: An Encyclopedia of Principles and Practice. FRCA Study Guides (5 ed.). Elsevier Health Sciences. ISBN 978-0-7020-5375-7.{{cite book}}: CS1 maint: multiple names: authors list (link)

[2] "'French', 'gauge' and millimeters". University of California, San Francisco . Archived from the original on 2017-08-18. Retrieved 2018-02-03.

[MH-3] Machinery's Handbook 27. New York, NY: Industrial Press, Inc. 2004. p. 2520.

[Sigma-4] 1 2 "Syringe Needle Gauge Chart". Sigma Aldrich. Retrieved 20 March 2012.

[5] "Hypodermic Needle Gauge Chart". Medical Tube Technology, Inc. Archived from the original on 10 October 2004. Retrieved 20 March 2012.

[7] "ISO 6009:2016 Hypodermic needles for single use -- Colour coding for identification". International Organization for Standardization . Publication date: 2016-08

[MillerSchlueter2004-8] Miller, Michal A.; Schlueter, Annette J. (2004). "Transfusions via hand-held syringes and small-gauge needles as risk factors for hyperkalemia". Transfusion. 44 (3): 373–381. doi:10.1111/j.1537-2995.2004.00653.x. ISSN 0041-1132. PMID 14996194. S2CID 22956171.

[Doyle-9] 1 2 3 4 5 6 7 8 9 10 Page 110 in: Edward Doyle (2007). Pediatric Anesthesia. OUP Oxford. ISBN 978-0-19-920279-9.

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