Tubing Size Reference Chart

Gauge

For swivels, blunt needles, couplers, plugs, PinPorts


Gauge
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
13TW 0.095 2.41 0.077 1.96 30.0
13 0.095 2.41 0.071 1.80 25.5
14TW 0.083 2.11 0.067 1.70 22.8
14 0.083 2.11 0.063 1.60 20.1
15TW 0.072 1.83 0.061 1.55 18.9
15 0.072 1.83 0.054 1.37 14.8
16TW 0.065 1.65 0.054 1.37 14.8
16 0.065 1.65 0.047 1.19 11.1
17TW 0.058 1.47 0.048 1.22 11.7
17 0.058 1.47 0.042 1.07 8.99
18TW 0.050 1.27 0.039 0.99 7.70
18 0.050 1.27 0.033 0.84 5.54
19TW 0.042 1.07 0.033 0.84 5.54
19 0.042 1.07 0.027 0.69 3.74
20TW 0.036 0.91 0.026 0.66 3.42
20 0.036 0.91 0.024 0.61 2.92
21TW 0.032 0.81 0.023 0.58 2.64
21 0.032 0.81 0.020 0.51 2.04
22TW 0.028 0.71 0.020 0.51 2.04
22 0.028 0.71 0.016 0.41 1.32
22Q 0.028 0.71 0.006 0.15 0.18
23TW 0.025 0.64 0.017 0.43 1.45
23 0.025 0.64 0.013 0.33 0.86
24TW 0.022 0.56 0.015 0.38 1.13
24 0.022 0.56 0.012 0.30 0.71
25TW 0.020 0.51 0.012 0.30 0.71
25 0.020 0.51 0.010 0.25 0.49
26 0.018 0.46 0.010 0.25 0.49
27 0.016 0.41 0.008 0.20 0.31
28 0.014 0.36 0.007 0.18 0.25
29 0.013 0.33 0.007 0.18 0.25
30 0.012 0.30 0.006 0.15 0.18
31 0.010 0.26 0.005 0.13 0.12
32 0.009 0.24 0.004 0.10 0.08

 

 

French

Describes catheter OD (3Fr=1mm)


French
OD
(in)
OD
(mm)

Gauge

PE
1Fr 0.013 0.33 27 -
2Fr 0.026 0.67 23 PE-10
3Fr 0.039 1.00 20 PE-50
4Fr 0.053 1.33 18 PE-90
5Fr 0.066 1.67 16 PE-190
6Fr 0.079 2.00 14 PE-205
7Fr 0.092 2.33 13 PE-240
8Fr 0.105 2.67 12 PE-260
9Fr 0.118 3.00 11 -
10Fr 0.131 3.33 10 PE-280

 

 

Intravascular Polyurethane (PU)

For finished catheters, bulk tubing


Size
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
BTPU-014 (1Fr) 0.014 0.36 0.007 0.18 0.3
BTPU-027 (2Fr) 0.027 0.69 0.017 0.43 1.5
BTPU-040 (3Fr) 0.040 1.01 0.025 0.64 3.2

 

 

External Polyurethane (PU)

For bulk tubing


Size
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
VAHBPU-T25 0.037 0.94 0.017 0.42 1.5
VAHBPU-T22 0.055 1.40 0.024 0.61 2.9

 

 

Silicone (Silastic®)

For bulk tubing


Size
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
2Fr 0.025 0.64 0.012 0.30 0.7
3Fr 0.037 0.94 0.020 0.51 2.0
3.5Fr 0.047 1.19 0.025 0.64 3.2
5Fr 0.065 1.65 0.030 0.76 4.5
7Fr 0.085 2.16 0.040 1.02 8.2

 

 

Polyethylene (PE)

For bulk tubing


Size
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
PE-10 0.024 0.61 0.011 0.28 0.6
PE-20 0.043 1.09 0.015 0.38 1.1
PE-25 0.036 0.91 0.018 0.46 1.7
PE-50 0.038 0.97 0.023 0.58 2.6
PE-60 0.048 1.22 0.030 0.76 4.5
PE-90 0.050 1.27 0.034 0.86 5.8

 

 

Co-extruded PE/PVC tubing

For bulk tubing


Size
OD
(in)
OD
(mm)
ID
(in)
ID
(mm)
Vol
(µl/cm)
BTCOEX-25 0.051 1.30 0.017 0.43 1.5
BTCOEX-22 0.064 1.60 0.024 0.61 2.9
BTCOEX-22B 0.072 1.83 0.024 0.61 2.9

 

 

Instech does not sell all sizes of tubing shown here. Follow links above each chart for available sizes and prices. Values are approximate; in particular IDs of extruded tubing typically vary by �0.002in (0.05mm) from nominal values. If dead volume is critical measure the tubing you are using directly by comparing the weights of a filled and empty sample.