Needle Gauge Chart
| Gauge Number | Needle Nominal O.D. (mm) | Needle Nominal I.D. (mm) | Needle Wall Thickness (mm) | Needle Dead Volume (µL/25.4 mm) |
| 34 gauge needle | 0.159 | 0.051 | 0.051 | 0.052 µL/25.4 mm |
| 33 gauge needle | 0.21 | 0.108 | 0.051 | 0.233 µL/25.4 mm |
| 32 gauge needle | 0.235 | 0.108 | 0.064 | 0.233 µL/25.4 mm |
| 31 gauge needle | 0.261 | 0.133 | 0.064 | 0.353 µL/25.4 mm |
What does the gauge of a needle signify?
What is the gauge of a needle mean? Needle Gauge. The gauge refers to the inner measurement or opening of the needle. Needles are routinely available in a variety of gauge sizes, including 18, 21, 23, and 25 gauge, as shown in the image. The needle gauge becomes a consideration when the vein of the patient is narrow, fragile, or superficial.
Which needle gauge has the largest bore or lumen?
The higher the gauge, the smaller the diameter. For example, a 30 gauge needle has a narrower lumen than a 25 gauge needle. Different companies use different measurements for gauges, so it is important to specify inner diameter.
What needle gauge would have the smallest diameter?
When buying syringes, keep these things in mind: Needle gauge: The gauge of the needle means its width, or thickness. Insulin syringes range from 28 gauge to 31 gauge, and the larger the number the smaller the gauge. (An Ultra-Fine II brand needle is the smallest, and the Ultra-Fine is the next size up.)
What does gauge refer to on needle size?
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Which is bigger 21 or 22 gauge needle?
As the gauge number increases, the needle width gets narrower. For example, a 22g needle is thinner than a 21g. This difference is critical to remember, as there is no uniform gauge size for all phlebotomist patients.
Is 23 or 25 gauge needle bigger?
The gauge size of a needle indicates what the diameter of the lumen (opening) is. The higher the gauge, the smaller the diameter....Plastic (Straight 0.25″, 0.5″, or 1.0″)Gauge SizeInner Diameter (mm)Color230.330Orange240.300Blue-Green250.250Red260.240Peach5 more rows
Which is bigger 18 or 20 gauge needle?
IV needles are sized by gauges, and the smaller the gauge number, the bigger the needle will be. In this article and video, I'll discuss the three most common IV gauge needles you'll encounter as a nurse: 18 gauge, 20 gauge, and 22 gauge.
Is a 22 or 24 gauge needle bigger?
Needle gauge tableNeedle gaugeOuter diameter (inches)Inner diameter (mm)220.028250.41322s0.028250.152230.025250.337240.022250.31126 more rows•May 20, 2019
Which needle is the smallest?
The smallest, thinnest needle is the nano 4 mm, 32 gauge needle, which is about as thin as two strands of hair.
What is a 22 gauge needle used for?
A 22-gauge 3.8-cm (1.5 in.) needle is used for superficial muscles. When capillary fragility with bleeding is a concern, a thinner 25-gauge needle may be preferred. In thick subcutaneous muscles, at least a 21-gauge 5-cm (2-in.)
What gauge is used for IV?
💉20 GAUGE (Pink): The 20 gauge needle is better for adult patients with smaller veins and in pediatrics. This size is ideal for IV infusion and blood infusion.
What needle is used for IV?
A butterfly needle is a device used to draw blood from a vein or deliver intravenous (IV) therapy to a vein. A butterfly needle consists of a very thin needle, two flexible “wings,” a flexible transparent tubing, and a connector.
How do I choose a needle gauge?
Determining Needle SizeThe first number in front of the letter G indicates the gauge of the needle. The higher this number is, the thinner the needle.The second number indicates the length of the needle in inches.
Is 21 or 23 gauge needle smaller?
Needle Measurement The higher the number, the finer or thinner the needle. For example, a 30-gauge needle is smaller than a 27-gauge needle. Length: How long the needle is.
What is 20 gauge needle used for?
These are regular-walled medical point needles. They are for intramuscular, subcutaneous, and other injections and are available in a wide range of gauges and lengths.
What is a 25 gauge needle used for?
The length of a needle is listed after the gauge number. For example, 25G ½ refers to a 25 gauge, ½ inch-long needle. Longer needles (½ inch or longer) are commonly used for intramuscular injections, while shorter (shorter than ½ inch) needles are more often used for intravenous injections.
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What is the diameter of a needle gauge?
Tip: always use a needle with a larger outer diameter than the inner diameter of your tubing! Needle gauge. Outer diameter (inches) Outer diameter (mm) Inner diameter (inches) Inner diameter (mm) 7. 0.180. 4.572.
What is a 23G needle?
You can use it to determine the needle you should use depending on the inner diameter of your soft-walled tubing. Example: 23G needle = 0.02525" or 0.6414 mm ( inner diameter) - 0.01325" or 0.337 mm (outer diameter). Tip: always use a needle with ...
What happens to needle caliber as the gauge number increases?
Moreover, as the Gauge number increases, the needle caliber decreases. Although there is not an equal increment between each step in the system, the caliber decreases by ≈11% per increment. The lowest and highest allowable gauges are pre-defined and published tables state the sizing of every available gauge. Attempts have been made ...
When was the first gauge system invented?
When the UK became the first country in the world to standardize a gauge system in 1884, an attempt was made to make the increments between the gauge numbers more regular. This system was known as the British Standard Wire Gauge, and it was developed from the older Birmingham gauge system.
How was gauge wire made?
For centuries, wire was manufactured by a process known as 'drawing'. The process of wire-making started with a thick wire , and thinner wires were made by pulling (or drawing) the wire through progressively smaller holes. The size of the largest wire that one could start with was limited by the force that could be generated to pull it through a smaller hole. In the pre-steam age, the greatest force could be supplied by horse or a water-wheel.
Why is the gauge size not derived from a formula?
It was adopted from pre-existing gauges which were used in industry to size metal wire. In contradistinction to the French scale , the other well-known sizing system, which is a metric system, the Gauge size cannot be derived from a straightforward formula. This is because the size was not designed to be an absolute measure, ...
What gauges are used to avoid negative numbers?
To avoid negative numbers the gauges greater than 1 were designated 0, 1/0, 2/0 etc. Each wire-maker would have a standard metal gauge for their customers' use by which they could choose the thickness of wire they might require and also verify that their purchased wire was of the stated size.
Do peripheral and central venous catheters use the same measurement for cannula size?
Although peripheral and central venous catheters use the same measurement for cannula size, the color system for PVCs is different from the ISO needles above:
Is the Gauge scale a metric or metric?
In contradistinction to the French scale, the other well-known sizing system, which is a metric system, the Gauge size cannot be derived from a straightforward formula. This is because the size was not designed to be an absolute measure, but instead a relative scale. Moreover, as the Gauge number increases, the needle caliber decreases.
Needle Size and Choice
Needle gauges are sized numerically, with the smaller numbers correlating to larger needles and larger numbers correlating to smaller needles. In general, the smallest appropriately sized needle is used. The most common sizes are 18, 20, and 22 gauge.
Other Considerations
The gauge size also varies with the purpose of the stick. For example, if the patient needs to have blood drawn or requires infusion of blood products, some of the smaller gauges may be contraindicated because the small bore can damage the cells.
Basic Needle Gauges and Uses
Remember that the larger the needle gauge number, the smaller the size of the needle. These are the more commonly used needle gauges and their general purposes:
What gauge needles are used for IV?
Different Types of IV Gauge Needles: 18, 20, and 22 Gauge Needles. One of the of the important things to know when starting an IV is the proper needle size to use. IV needles are sized by gauges, and the smaller the gauge number, the bigger the needle will be.
What size needles are used for pediatrics?
There is a size 24 gauge that is mostly used for pediatrics due to its small size. There are also 16 gauge needles that are used primarily for ICU or surgery. Nevertheless, 18, 20, and 22 gauge is the size you’ll encounter most frequently in most areas of nursing.
Why are retractable needles used in IVs?
Therefore, the retractable needle feature in most IVs today can help reduce the risk of accidental (or intentional) needle sticks.
How many gauge IV needles are needed for blood product administration?
Most hospital protocols will outline for you what gauge of IV needles you can use for blood product administration. Some hospitals allow you to use 20 or 22 gauge IV needles in the adult population, however, some do not and may require a central line. So, always check with your organization’s policy.
Why is it important to use the right gauge?
The reason it’s important to use the right gauge is because some nursing procedures can only be done with a particular sized needle. For example, if you have a patient who needs to have his or her blood drawn, you’ll want to go with a gauge large enough to do it.
What color is an IV needle?
Luckily, most manufacturers color code their IV needles. Here’s a little rhyme you can use to help you remember what colors correspond to what sized gauge: 22 is blue and 18 is green. Pink is the one in the middle. There are other IV gauge sizes besides those, although they aren’t as common. There is a size 24 gauge that is mostly used ...
What is a 16 gauge?
16 Gauge: This size is mostly used in the ICU or surgery areas. This large size enables many different procedures to be performed, such as blood administration, rapid fluid administration, and so forth.
Why is it important to choose the right size needle and syringe?
Choosing the right size needle and syringe is necessary to get the correct dose of medicine, inject it properly, and minimize pain. 1 To make it easier, these items are sold separately and designed to attach securely. Your doctor or a nurse will show you how to administer your injections at home, including which syringes and needles to use.
Which needle is better for injections?
For larger amounts of medicine, a wider needle with a lower gauge is often a better choice. While it might hurt more, a wide, low-gauge needle will deliver the injection faster than a thin, high-gauge needle. 5 .
How long should a needle be for intramuscular injection?
5 Muscle is deeper than skin, so the needle used for these shots must be thicker and longer. Needles with a gauge of 20 or 22 G and a length of 1 or 1.5 inches are usually best.
What to do if you have questions about needle size?
If you have questions, reach out to the healthcare provider who prescribed the medication. Knowing the basics of needle size labeling will help you avoid making errors when you're giving the shot and replacing your supplies.
How are syringes labeled?
Syringes are labeled based on how much liquid they can hold. There are two ways to measure them.
What do you see on a syringe?
Syringes can hold liquids or solids. You'll see milliliters (mL) marked on the tube for measuring liquids . You'll see cubic centimeters (cc) for measuring solids. Try to choose a syringe that holds the exact dose you need.
How many cc is in a syringe?
If you use a syringe that contains only 2 cc, you would have to inject yourself more than once (which would be unnecessarily painful). On the other hand, if you use a syringe that holds 15 cc, it will be harder to see the cc markings and measure 3 cc accurately.
What does gauge mean in needles?
When we talk about the gauge of a needle we are referring to the size of the hole in the needle. The higher the gauge, the smaller the hole. The lower the gauge the wider the hole.
How to know what gauge needle to use?
How do I know what gauge needle to use? The size of the needle must match the size of the vein. A 21 gauge is used on a big vein. A 23 gauge is used on a small vein. If the vein can’t be seen use the tip of the index or middle finger to search and feel for the vein. Feeling the vein will give you an idea of its size. Choose a gauge needle accordingly.
What Gauge Needles Are Used For Donating Blood?
A large amount of blood is drawn during donation. It can vary from 200 to 550 ml depending on the country but 450 to 500 ml is typical. A 16, 17, or 18 gauge needle is used. This will vary from country to country. A 16 gauge may be the go-to in one country while an 18 gauge may be more common in another.
What About The 22 Gauge Needle?
The 22 gauge needle falls somewhere between the 21 and 23 gauge. Use it for adults who have medium-sized veins and for older children.
How fast does a 21 gauge needle fill?
When filling tubes pay close attention because if you don’t you may draw more blood than you need. Depending on the size of the tube and the flow of blood, a tube will fill in 2 to 8 seconds.
What is the difference between gauge needle numbers?
What is the difference between gauge needle numbers? The numbers refer to the size of the hole in the needle. Lower numbers mean that the hole in the needle is wide. Higher numbers mean that the hole in the needle is small. So, as the numbers get lower the hole gets wider and as the numbers get higher the hole gets smaller.
What gauge is used for blood?
Of all 3, the 21 gauge is the most common used when drawing blood. It is the go-to gauge for most adults with plump veins. The hole through which blood flows is wide enough to allow for a fast flow of blood while maintaining the integrity of the sample.
