B - PERFORMING OPERATIONS
B21 - MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
B21C - MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING
F - MECHANICAL ENGINEERING
F28 - HEAT EXCHANGE IN GENERAL
F28D - HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
B - PERFORMING OPERATIONS
B21 - MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
B21C - MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING
B21C37/06 - of tubes or metal hoses
B21C37/202 - {with guides parallel to the tube axis}
B21C37/30 - Finishing tubes, e.g. sizing, burnishing
F - MECHANICAL ENGINEERING
F28 - HEAT EXCHANGE IN GENERAL
F28D - HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
F28D15/046 - {characterised by the material or the construction of the capillary structure}
F - MECHANICAL ENGINEERING
F28 - HEAT EXCHANGE IN GENERAL
F28F - DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
F28F1/40 - the means being only inside the tubular element
Y - NEW / CROSS SECTIONAL TECHNOLOGIES
Y10 - TECHNICAL SUBJECTS COVERED BY FORMER USPC
Y10T - TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
Y10T29/49353 - Heat pipe device making
Y10T29/4981 - Utilizing transitory attached element or associated separate material
Y10T29/49888 - Subsequently coating