Syringe Needle Gauge Table

Published by ELEXAN Scientific on Jul 11th 2025

Needle Gauge and Tubing Selection

Choosing the correct needle gauge is critical in microfluidic applications for several reasons:

Leak Prevention: Proper gauge selection ensures a tight seal between the needle and tubing, preventing fluid leakage which is crucial in microfluidic systems where sample volumes are small.
Flow Control: The inner diameter directly affects flow rate and pressure, important for precise fluid handling.
Material Compatibility: The gauge affects how much the tubing is compressed, which can impact both seal quality and potential damage to soft tubing materials.
Dead Volume: Proper sizing minimizes dead volume in connections.

For soft-wall tubing, we recommend a compression between 5% and 15% for safe sealing, with 10% as the ideal target. Always test your specific tubing–needle combination for optimal performance. This dynamic table helps you find the inner diameter (ID) and outer diameter (OD) of needles by highlighting the closest matches to your search criteria.

Needle Gauge	OD (in)	OD (mm)	ID (in)	ID (mm)
7	0.180	4.572	0.150	3.810
8	0.165	4.191	0.135	3.429
9	0.148	3.759	0.118	2.997
10	0.134	3.404	0.106	2.692
11	0.120	3.048	0.094	2.388
12	0.109	2.769	0.085	2.159
13	0.095	2.413	0.071	1.803
14	0.083	2.108	0.063	1.600
15	0.072	1.829	0.054	1.372
16	0.065	1.651	0.047	1.194
17	0.058	1.473	0.042	1.067
18	0.050	1.270	0.033	0.838
19	0.042	1.067	0.027	0.686
20	0.03575	0.9081	0.02375	0.603
21	0.03225	0.8192	0.02025	0.514
22	0.02825	0.7176	0.01625	0.413
22.s	0.02825	0.7176	0.006	0.152
23	0.02525	0.6414	0.01325	0.337
24	0.02225	0.5652	0.01225	0.311
25	0.02025	0.5144	0.01025	0.260
26	0.01825	0.4636	0.01025	0.260
26.s	0.01865	0.4737	0.005	0.127
27	0.01625	0.4128	0.00825	0.210
28	0.01425	0.3620	0.00725	0.184
29	0.01325	0.3366	0.00725	0.184
30	0.01225	0.3112	0.00625	0.159
31	0.01025	0.2604	0.00525	0.133
32	0.00925	0.2350	0.00425	0.108
33	0.00825	0.2096	0.00425	0.108
34	0.00725	0.1842	0.00325	0.0826