The lower the number , the larger/thicker the needles. 14/16's are usually good for our needs.
(as an example under the skin hypo's are 23 or 25g, and are tiny in comparison)
Edit: chart
Needle | Nominal Outer Diameter | Nominal Inner Diameter | Nominal Wall Thickness | | | | | | |
Gauge | inches | mm | tol. inches (mm) | inches | mm | tol. inches (mm) | inches | mm | tol. inches (mm) |
7 | 0.180 | 4.572 | ±0.001 (±0.025) | 0.150 | 3.810 | ±0.003 (±0.076) | 0.015 | 0.381 | ±0.001 (±0.025) |
8 | 0.165 | 4.191 | ±0.001 (±0.025) | 0.135 | 3.429 | ±0.003 (±0.076) | 0.015 | 0.381 | ±0.001 (±0.025) |
9 | 0.148 | 3.759 | ±0.001 (±0.025) | 0.118 | 2.997 | ±0.003 (±0.076) | 0.015 | 0.381 | ±0.001 (±0.025) |
10 | 0.134 | 3.404 | ±0.001 (±0.025) | 0.106 | 2.692 | ±0.003 (±0.076) | 0.014 | 0.356 | ±0.001 (±0.025) |
11 | 0.120 | 3.048 | ±0.001 (±0.025) | 0.094 | 2.388 | ±0.003 (±0.076) | 0.013 | 0.330 | ±0.001 (±0.025) |
12 | 0.109 | 2.769 | ±0.001 (±0.025) | 0.085 | 2.159 | ±0.003 (±0.076) | 0.012 | 0.305 | ±0.001 (±0.025) |
13 | 0.095 | 2.413 | ±0.001 (±0.025) | 0.071 | 1.803 | ±0.003 (±0.076) | 0.012 | 0.305 | ±0.001 (±0.025) |
14 | 0.083 | 2.108 | ±0.001 (±0.025) | 0.063 | 1.600 | ±0.003 (±0.076) | 0.01 | 0.254 | ±0.001 (±0.025) |
15 | 0.072 | 1.829 | ±0.0005 (±0.013) | 0.054 | 1.372 | ±0.0015 (±0.038) | 0.009 | 0.229 | ±0.0005 (±0.013) |
16 | 0.065 | 1.651 | ±0.0005 (±0.013) | 0.047 | 1.194 | ±0.0015 (±0.038) | 0.009 | 0.229 | ±0.0005 (±0.013) |
17 | 0.058 | 1.473 | ±0.0005 (±0.013) | 0.042 | 1.067 | ±0.0015 (±0.038) | 0.008 | 0.203 | ±0.0005 (±0.013) |
18 | 0.050 | 1.270 | ±0.0005 (±0.013) | 0.033 | 0.838 | ±0.0015 (±0.038) | 0.0085 | 0.216 | ±0.0005 (±0.013) |
19 | 0.042 | 1.067 | ±0.0005 (±0.013) | 0.027 | 0.686 | ±0.0015 (±0.038) | 0.0075 | 0.191 | ±0.0005 (±0.013) |
20 | 0.03575 | 0.9081 | ±0.00025 (±0.0064) | 0.02375 | 0.603 | ±0.00075 (±0.019) | 0.006 | 0.1524 | ±0.00025 (±0.0064) |
21 | 0.03225 | 0.8192 | ±0.00025 (±0.0064) | 0.02025 | 0.514 | ±0.00075 (±0.019) | 0.006 | 0.1524 | ±0.00025 (±0.0064) |
22 | 0.02825 | 0.7176 | ±0.00025 (±0.0064) | 0.01625 | 0.413 | ±0.00075 (±0.019) | 0.006 | 0.1524 | ±0.00025 (±0.0064) |
22s | 0.02825 | 0.7176 | ±0.00025 (±0.0064) | 0.006 | 0.152 | ±0.00075 (±0.019) | 0.0111 | 0.2826 | ±0.00025 (±0.0064) |
23 | 0.02525 | 0.6414 | ±0.00025 (±0.0064) | 0.01325 | 0.337 | ±0.00075 (±0.019) | 0.006 | 0.1524 | ±0.00025 (±0.0064) |
24 | 0.02225 | 0.5652 | ±0.00025 (±0.0064) | 0.01225 | 0.311 | ±0.00075 (±0.019) | 0.005 | 0.1270 | ±0.00025 (±0.0064) |
25 | 0.02025 | 0.5144 | ±0.00025 (±0.0064) | 0.01025 | 0.260 | ±0.00075 (±0.019) | 0.005 | 0.1270 | ±0.00025 (±0.0064) |
26 | 0.01825 | 0.4636 | ±0.00025 (±0.0064) | 0.01025 | 0.260 | ±0.00075 (±0.019) | 0.004 | 0.1016 | ±0.00025 (±0.0064) |
26s | 0.01865 | 0.4737 | ±0.00025 (±0.0064) | 0.005 | 0.127 | ±0.00075 (±0.019) | 0.0068 | 0.1734 | ±0.00025 (±0.0064) |
27 | 0.01625 | 0.4128 | ±0.00025 (±0.0064) | 0.00825 | 0.210 | ±0.00075 (±0.019) | 0.004 | 0.1016 | ±0.00025 (±0.0064) |
28 | 0.01425 | 0.3620 | ±0.00025 (±0.0064) | 0.00725 | 0.184 | ±0.00075 (±0.019) | 0.0035 | 0.0889 | ±0.00025 (±0.0064) |
29 | 0.01325 | 0.3366 | ±0.00025 (±0.0064) | 0.00725 | 0.184 | ±0.00075 (±0.019) | 0.003 | 0.0762 | ±0.00025 (±0.0064) |
30 | 0.01225 | 0.3112 | ±0.00025 (±0.0064) | 0.00625 | 0.159 | ±0.00075 (±0.019) | 0.003 | 0.0762 | ±0.00025 (±0.0064) |
31 | 0.01025 | 0.2604 | ±0.00025 (±0.0064) | 0.00525 | 0.133 | ±0.00075 (±0.019) | 0.0025 | 0.0635 | ±0.00025 (±0.0064) |
32 | 0.00925 | 0.2350 | ±0.00025 (±0.0064) | 0.00425 | 0.108 | ±0.00075 (±0.019) | 0.0025 | 0.0635 | ±0.00025 (±0.0064) |
33 | 0.00825 | 0.2096 | ±0.00025 (±0.0064) | 0.00425 | 0.108 | ±0.00075 (±0.019) | 0.002 | 0.0508 | ±0.00025 (±0.0064) |
34 | 0.00725 | 0.1842 | ±0.00025 (±0.0064) | 0.00325 | 0.0826 | ±0.00075 (±0.019) | 0.002 | 0.0508 | ±0.00025 (±0.0064) |
Last edited: