Capillary Tubes

Capillary tubes are precision-engineered tubes with extremely small internal diameters designed for applications requiring accurate flow control, measurement, and thermal transfer. These tubes are widely used in refrigeration systems, instrumentation, analytical equipment, laboratory devices, and medical instruments.

KamTube Instruments LLP manufactures high-precision stainless steel and nickel alloy capillary tubes with tight dimensional tolerances, smooth internal surfaces, and excellent mechanical strength. Our capillary tubes are available in coils, straight lengths, and custom cut-to-length formats for various industrial applications.

Whether you need micro-capillary tubing for scientific instrumentation or long coil tubes for refrigeration and flow-control applications, KamTube Instruments LLP provides tailor-made solutions to meet global industry standards and customer-specific requirements.

Specification Table

Parameter	Specification
Outer Diameter (OD)	0.30 mm to 12.70 mm
Wall Thickness	0.05 mm to 1.50 mm
Inner Diameter (ID)	0.10 mm to 10.00 mm
Tolerance	±0.02 mm (custom available)
Length	Coils up to 300 meters / Straight lengths up to 6 meters
Surface Finish	Bright Annealed / Polished / Cleaned & Passivated
Form	Coiled, Straight, Cut-to-Length

Materials & Grades Table

Material	Grade	Applications
Stainless Steel	304, 304L, 316, 316L, 321	Instrumentation, medical devices, chemical processing
Copper	C12200, C11000	Refrigeration and HVAC capillary tubes
Nickel Alloys	Inconel 600, 625, Monel 400	High-temperature & corrosive environments
Titanium	Grade 2, Grade 5	Aerospace, biomedical equipment

Capillary Tube Sizes

Gauge	Capillary Tube Size Chart
	Tolerance for Outside Diameter	Thin Wall (TW)	Ultra Thin Wall (UTW)	Regular Wall (RW)	Extra Thin Wall (XTW)
	Millimeter	Millimeter	Millimeter	Millimeter	Millimeter
10	3.378 – 3.429	0.216 – 0.292		0.318 – 0.394
11	3.023 – 3.073	0.216 – 0.292		0.293 – 0.368
12	2.743 – 2.749			0.267 – 0.321
13	2.387 – 2.438	0.191 – 0.267		0.267 – 0.343
14	2.082 – 2.133	0.165 – 0.229	0.076 – 0.134	0.216 – 0.292	0.114 – 0.165
15	1.816 – 1.841	0.127 – 0.165	0.070 – 0.121	0.204 – 0.254	0.096 – 0.134
16	1.638 – 1.663	0.127 – 0.165	0.070 – 0.121	0.204 – 0.254	0.096 – 0.133
17	1.460 – 1.485	0.115 – 0.152	0.057 – 0.102	0.177 – 0.229	0.083 – 0.127
18	1.257 – 1.282	0.127 – 0.165	0.051 – 0.102	0.191 – 0.241	0.083 – 0.121
19	1.054 – 1.079	0.102 – 0.140		0.166 – 0.216	0.070 – 0.108
20	0.901 – 0.914	0.108 – 0.134		0.108 – 0.165
21	0.812 – 0.825	0.102 – 0.127	0.051 – 0.102	0.140 – 0.165
22	0.711 – 0.723	0.096 – 0.121	0.051 – 0.102	0.140 – 0.165	0.077 – 0.102
23	0.635 – 0.647	0.089 – 0.114	0.051 – 0.102	0.140 – 0.165
24	0.558 – 0.571	0.089 – 0.114	0.051 – 0.102	0.114 – 0.140
25	0.508 – 0.520	0.089 – 0.114		0.115 – 0.140
26	0.457 – 0.469			0.089 – 0.114
27	0.406 – 0.419	0.064 – 0.089		0.089 – 0.115
28	0.355 – 0.368			0.076 – 0.102
29	o.330 – 0.342			0.064 – 0.089
30	0.304 – 0.317			0.064 – 0.089

Key Features

Our capillary tubes are engineered to deliver consistent performance across industrial, medical, laboratory, and refrigeration applications.