Excel Metal & Engg Industries

The latest technology used in construction of buildings and bridges. They are used as a major element in the composite structure. Excellent quality, high load bearing capacity, durability, faster speed of construction, etc. are some of the reasons why it is gaining popularity in the construction industry.

"Shear connector means headed steel studs. These are welded to a structural member for achieving composite action with concrete. Shear connector is one of the major elements in the composite structure

The latest technology used in construction of buildings and bridges. They are used as a major element in the composite structure. Excellent quality, high load bearing capacity, durability, faster speed of construction, etc. are some of the reasons why it is gaining popularity in the construction industry.

"Shear connector means headed steel studs. These are welded to a structural member for achieving composite action with concrete. Shear connector is one of the major elements in the composite structure

Length: Length is listed before weld. Studs diameters 1/2” and below will be approx. 1/8” shorter after welding. 5/8” will be approx. 3/16” shorter after welding. Stud Welding Products RB Studs can be made in any length above the standard minimum.

Material: Low carbon steel, ASTM A29, 1010 1020. RB studs are also available in weldable stainless steel. Type 302 is the most commonly used. Other grades of stainless steel (except Type 303) are available when required.

Ceramic Ferrule are essential part of the standard shear connectors (shear studs) drawn arc stud welding process. In the process, the shear connector will insert into the center hole of the ceramic ferrule, the ceramic ferrule will be pressed on the welding surface by ceramic ferrule holder by the force of spring device inside the welding gun. The ceramic ferrule is used for one weld only and is removed once the molten metal has solidified. It has following functions:
• Protection of the weld pool by creation of metal vapour in the burning chamber at sufficient current intensity,
• Concentration and stabilization of the arc, thus reducing arc blow,
• Further more, it shields the operator from both arc and spatter.

These standard ceramic ferrule are according to ISO 13918: 2008 Type UF, for shear connector welded to steel member in PA position.

Special Ceramic Ferrule for shear connectors welding through metal deck (mostly zinc-plated deck sheets on the steel beams). As there are high amounts of degasification through zinc evaporation when weld shear connectors through zinc-plated deck sheets, the type of WTD ceramic ferrule with larger combustion chamber and larger vents can considerably improve the welding results.

When welding to vertical surface, gravity causes molten metal to flow to the bottom side of the ferrule. There are increased tendency towar dmetal loss through the ferrule vents, and more difficult to displace the metal to the top of the weld. This is important for the development of a full formed weld collar. Special Ceramic Ferrule for shear connectors welding to vertical surface, they have blocked vents at the bottom of the ferrule cavity to prevent weld metal loss, and deposit more of the weld collar at the top of the weld.

Studded Tubes

These are metal tubes with studs welded on the OD throughout the length in a specific pattern, and used in fired heaters in refineries and also in water tube boilers.

• To increase the surface area of the tube and to protect tube surface from direct exposure to heat / corrosive environment
• Studding reduces the amount of bare pipes used in these processes. Heat transfer surface of one studded pipe is equivalent to surface of 4 to 10 bare pipes.
• Use of studded tubes is ideal for processes / applications, where dirty fuels are used in harsh environments

studding is done by resistance welding machine. The linear and angular pitch is precisely maintained by PLC controller. Studs are welded on tubes having diameter from 4" to 8" and length maximum upto 12 meters.

Pipe materials  We use tube materials as Mild Steel or Alloy Steel like grades P3, P5, P9, P11 etc. Stud Material is generally Mild Steel or as per customer requirement.

These are welded by generation of arc between stud and base material. Ceramic ferule is used to contain the molten material and protect the welder's eyes. The raw material, diameter and length of studs will vary depending on requirement of customer.

These types of studs are mostly used in

• Transformers
• Switchgears
• Boilers