What Do 10 Number and 12 Number Welding Rods Mean in Pakistan?
Complete guide to Pakistani welding electrode trade sizes. Understand what 10-number and 12-number rods mean in metric millimeters, SWG gauge history, amperage settings, and box packaging specs.
Direct Answer for Pakistani Fabricators & Contractors
Why Does Pakistan Use "Number" Instead of Millimeters?
If you visit hardware markets in Badami Bagh Lahore, Shershah Karachi, City Saddar Road Rawalpindi, or Railway Road Multan, shopkeepers (dukan-dar) and seasoned welders (ustads) rarely ask for "2.5 mm" or "3.2 mm" electrodes. Instead, they consistently order "10 number dabba" or "12 number packet".
This trade convention dates back to pre-metric industrial standards in British India, where wire and sheet metal thicknesses were cataloged under the Imperial Standard Wire Gauge (SWG) system: - In the SWG system, a higher gauge number represents a thinner wire. - Thus, a 12-number rod (SWG 12 = 0.104 inches ≈ 2.64 mm, manufactured to 2.5 mm metric standard) is thinner than a 10-number rod (SWG 10 = 0.128 inches ≈ 3.25 mm, manufactured to 3.2 mm metric standard). - Today, Pakistani primary manufacturers like Perfect Craft (Pvt.) Ltd. produce electrodes to exact metric specifications (2.5 mm, 3.2 mm, 4.0 mm, 5.0 mm) under international AWS A5.1 and JIS Z 3211 standards, while printing both the metric diameter and the traditional gauge number on every box to eliminate field confusion.
Complete Pakistan Trade Size Conversion & Operating Master Table
The table below reconciles local trade language, international metric engineering standards, recommended welding amperages, and packaging metrics:
| Local Trade Term | Metric Diameter | Rod Length | Core Wire Gauge | Recommended Current (Flat) | Vertical / Overhead Current | Standard Inner Box Weight | Estimated Rods per Box | Master Carton Packaging |
|---|---|---|---|---|---|---|---|---|
| 12 Number | 2.5 mm (3/32") | 300 mm | SWG 12 | 50 – 90 A | 50 – 80 A | 2.5 kg | ~140 – 150 pcs | 8 boxes × 2.5 kg = 20 kg |
| 10 Number | 3.2 mm (1/8") | 350 mm | SWG 10 | 90 – 130 A | 80 – 120 A | 5.0 kg | ~140 – 150 pcs | 4 boxes × 5.0 kg = 20 kg |
| 8 Number | 4.0 mm (5/32") | 400 mm | SWG 8 | 140 – 190 A | 120 – 170 A | 5.0 kg | ~90 – 100 pcs | 4 boxes × 5.0 kg = 20 kg |
| 6 Number | 5.0 mm (3/16") | 400 mm | SWG 6 | 180 – 240 A | 160 – 210 A | 5.0 kg | ~60 – 65 pcs | 4 boxes × 5.0 kg = 20 kg |
Operating Note: When welding in the vertical-up or overhead orientation, decrease machine amperage by approximately 10% to 15% to maintain molten weld pool control and prevent sagging.
What Does J421 Mean and How Does It Relate to 10 and 12 Number Rods?
Many contractors and fabricators in Pakistan notice the code "J421" printed on imported or local electrode packets alongside "10 number" or "12 number".
- What is J421? J421 is the classification code established under the Chinese National Standard (GB/T 5117 E4313) for carbon steel covered electrodes.
- Is J421 the same as AWS E6013? Technically, yes. Both J421 and AWS A5.1 E6013 describe an all-position, rutile-titanium coated mild steel electrode designed for AC and DC power sources:
- - "42" in J421 indicates a minimum tensile strength of 420 MPa (~60,000 psi, identical to the "60" in E6013).
- - "1" indicates all-position welding capability.
- - "J" stands for structural steel (Jiegou Gang).
- Both Perfect Bridge and Perfect King manufactured by Perfect Craft in Karachi conform to AWS A5.1 E6013, JIS Z 3211 D4313, and are 100% cross-compatible with J421 job specifications.
12 Number (2.5 mm) vs 10 Number (3.2 mm): Which One Should You Buy?
Choosing between 12-number and 10-number depends on the thickness of your base steel and the type of welding work:
When to choose 12 Number (2.5 mm): 1. **Thin Sheet Metal & Hollow Sections:** Best for metal thicknesses between **1.2 mm and 3.0 mm**. A 10-number rod will generate too much heat on thin gauge hollow sections (pipe/square tubes), causing severe burn-through (*surakh*). 2. **Decorative Grills & Gates:** Allows fine cosmetic ripples, minimal post-weld grinding, and precise bead placement on intricate ornamental ironwork. 3. **Low-Amperage Welding Machines:** Can be run effortlessly on small 140A–160A portable single-phase inverters or domestic 220V workshop connections without tripping breakers.
When to choose 10 Number (3.2 mm): 1. **General Structural Steel:** Ideal for metal thicknesses between **3.0 mm and 8.0 mm**. Used for building trusses, channel sections, angles, I-beams, and staircases. 2. **Faster Deposition Rate:** Deposits approximately 60% more weld metal per minute than a 12-number rod, cutting fabrication time in half on structural projects. 3. **Heavy Vehicle & Trailer Repair:** Provides adequate throat depth and penetration on chassis frames, agricultural trolleys, and dumper bodies.
Packaging Standards: Avoiding Market Fraud on Rod Counts & Box Weights
A common problem faced by Pakistani buyers in retail markets is receiving short-weight or repackaged electrodes. Here is how genuine manufacturer packaging works:
- Net Weight vs Gross Weight:
- Piece Counts per Box:
- Moisture-Resistant Inner Sealing:
Frequently Asked Questions (FAQ)
What is the exact price of a 10-number and 12-number welding rod box in Pakistan? Electrode prices in Pakistan fluctuate based on international billet prices, imported rutile flux costs, and currency exchange rates. As an indicative benchmark, a 2.5 kg box of 12-number rods ranges between PKR 850 and PKR 1,150, while a 5.0 kg box of 10-number rods ranges between PKR 1,650 and PKR 2,200 depending on volume and city. For today's verified factory wholesale rate, [request a live commercial quote](/quote/).
Can I weld 10-number rods with a domestic 220V household electricity connection? Yes, provided your welding machine is a modern inverter capable of delivering a sustained 110–130 Amperes. Standard household 15A or 20A circuit breakers may trip if you run heavy continuous welds on old oil-cooled transformer machines. For domestic power lines, a 12-number rod (50–90 A) is much gentler on the electrical supply.
Does Perfect Craft manufacture both 10-number and 12-number rods? Yes. Perfect Craft (Pvt.) Ltd. manufactures both **Perfect Bridge** and **Perfect King** in 12 Number (2.5 mm), 10 Number (3.2 mm), 8 Number (4.0 mm), and 6 Number (5.0 mm) at its Karachi manufacturing plant.
How do I order genuine Perfect Craft electrodes in my city? You can locate authorized distributors in Karachi, Lahore, Rawalpindi, Peshawar, Multan, and other major industrial hubs through our [Dealer Locator](/dealers/), or contact our factory sales desk at **(021) 32417795**.
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Published by Perfect Craft (Pvt.) Ltd., Karachi, Pakistan. For questions or technical verification, reach our engineering desk at [email protected].
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