Weld Stud

CD & Drawn Arc  ·  Copper Coated Mild Steel & Stainless Steel  ·  ISO 13918  ·  M3 to M16

Weld Stud — Specifications

Standard ISO 13918
Thread Sizes M3 to M16
Materials Copper Coated Mild Steel  ·  Stainless Steel
Finish — Mild Steel Copper Plated
Finish — Stainless Steel Passivated
Weld Stud CD Drawn Arc ISO 13918

Available In

Mild Steel
Copper Plated

For automotive, electronics and general fabrication.

Stainless
304 / 316

For outdoor, marine and food processing.

What Is a Weld Stud?

Excel Trading Corporation Provides weld studs in copper coated mild steel and stainless steel — CD process for thin sheet from 0.5mm, drawn arc for structural plate. ISO 13918 compliant, M3 to M16, with custom lengths available. Used in automotive fabrication, switchboard manufacturing, construction steel and electronics enclosures across India.

Excel Trading Corporation stocks weld studs as a speciality product — copper coated mild steel for CD welding on thin sheet, and stainless steel for applications requiring corrosion resistance. Both comply with ISO 13918, the international standard for arc stud welding fasteners.

Two Processes — Which Do You Need?

Click your base metal thickness to see the recommended process.

Copper Coated Mild Steel

CD Process · ISO 13918 · Standard Grade

Low carbon steel (equivalent to AISI 1006–1020) with standard copper plating. The copper coating improves chuck-to-stud conductivity for reliable arc initiation and provides corrosion protection during storage. Conical tip weld base ensures precise arc placement every time. Available M3 to M16 in standard and custom lengths.

Best for: Automotive body panels · Electronics sheet metal · Switchboard fabrication · General construction

Stainless Steel

AISI 304 Standard · 316 on Request · Passivated

300-series austenitic stainless steel, passivated finish. No copper coating — stainless is self-passivating and does not require it. Fully corrosion resistant in outdoor, coastal, food processing and pharmaceutical environments. Compatible with both CD and short cycle processes. Supplied annealed where required for optimum weldability.

Best for: Food processing equipment · Outdoor enclosures · Marine fabrication · Pharmaceutical panels

Where Are Weld Studs Used?

🚗

Automotive

Body panels, brackets, trim attachment, chassis

🏗️

Construction

Shear studs, refractory anchors, cable trays

⚡

Switchboards

Panel mounting, busbar supports, earthing studs

🖥️

Electronics

Enclosure sheet metal, rack chassis, telecom panels

Quick Specifications

M3–M16

Thread Sizes

ISO 13918

Standard

0.5mm+

Min Base Metal (CD)

1-Side

Access Required

For Best Weld Quality

  • ▸ Base metal surface must be clean, bare metal — free from paint, heavy rust, mill scale and grease. Surface prep takes seconds and dramatically improves weld consistency.
  • ▸ Match the stud diameter to your base metal thickness — do not weld large diameter studs to thin sheet using CD process.
  • ▸ Check for 360° weld flash around the full stud base after each weld — full flash confirms a good fusion. Partial flash indicates a cold weld and the stud should be rejected.
  • ▸ Bend test 2 studs at the start of each shift and after any size change — bend 30° with a pipe or hammer. The weld should hold with no cracking at the base.

Frequently Asked Questions

What is a weld stud and how is it installed?

A weld stud is a threaded fastener fused permanently to a metal surface using a stud welding gun — the entire weld completes in 1–6 milliseconds for CD studs. The gun holds the stud against the surface, triggers a rapid electrical discharge that melts the tip and creates an arc, then spring pressure drives the stud into the molten pool to form a full-fusion weld. No hole required, no reverse-side access needed, no visible marking on the other face.

What is the difference between CD and drawn arc weld studs?

CD (capacitor discharge) studs are for thin sheet metal under 2mm — the ultra-fast weld cycle prevents burn-through and distortion. They have a conical tip on the weld base and require no ferrules. Drawn arc studs are for thicker plate from 3mm and structural applications — the longer arc burn gives deep weld penetration and very high pull-out strength. They have a flux ball on the weld end and require ceramic ferrules to contain the molten pool.

Why are mild steel weld studs copper coated?

Copper coating improves electrical conductivity between the stud and the welding gun chuck, ensuring consistent arc ignition every time. It also provides corrosion protection during storage and transit. Copper coating is standard on all externally threaded mild steel CD studs. It does not apply to stainless steel studs, which are self-passivating and do not need it.

Can weld studs be installed on painted or coated surfaces?

Paint and coatings must be removed from the weld area before installation. Contaminants prevent proper arc initiation and fusion — the result is a cold weld with near-zero pull-out strength that will fail under load. A quick grind or wire brush of the weld spot is all that is needed. Drawn arc studs tolerate slightly more surface contamination than CD studs due to the longer, higher-energy arc.

Where can I buy weld studs in Bangalore?

Excel Trading Corporation stocks copper coated mild steel and stainless steel weld studs at our Kumbarpet store in Bengaluru. Weld studs are one of our speciality products — we supply to automotive fabricators, construction companies, switchboard manufacturers and electronics enclosure builders across Karnataka and India-wide. Call +91-9448239476 or email info@exceltrading.in for sizes, pricing and bulk quotes.