Construction and Structural Steelwork Fabrication
Base plates, gussets, cleats and stair components cut, drilled and welded to structural drawings for MENA construction
Structural steelwork on a construction site depends on connection plates arriving with holes on-centre and edges square, because a misaligned bolt pattern stops a crew mid-erection. CutLinq laser cuts and CNC drills base plates, gussets, cleats, splice plates and stair components from S235JR and S355J2 plate 6-40 mm, to the hole tolerances required for structural bolting per EN 1090.
This page covers the plate grades, standard connection details, hole and edge tolerances, and the galvanising or painting most contractors specify for exterior steel in Egypt, the UAE and Saudi Arabia.
Plate grades and thickness by connection type
S235JR covers light gussets and non-critical brackets; S355J2 is specified where the connection carries significant shear or moment load, such as column base plates and moment-frame splice plates. Thickness is set by the structural calculation, but CutLinq laser cuts up to 25 mm cleanly and plasma or waterjet handles 25-60 mm plate for base plates and heavy gussets.
Stair stringers and treads are typically S235JR 8-12 mm, laser or plasma cut then welded; checker plate (5+1 mm raised pattern) is a common tread finish specified for anti-slip in wet or dusty conditions.
| Connection type | Typical grade | Thickness range | Cutting process |
|---|---|---|---|
| Base plates | S355J2 | 16-40 mm | Plasma or waterjet |
| Gusset plates | S235JR / S355J2 | 8-20 mm | Fiber laser |
| Splice / cleat plates | S355J2 | 10-25 mm | Fiber laser |
| Stair stringers | S235JR | 8-12 mm | Fiber laser or plasma |
| Checker plate treads | S235JR | 5+1 mm raised | Plasma / oxy-fuel for large sheets |
| Handrail brackets | S235JR / 304 stainless | 4-8 mm | Fiber laser |
Hole and edge tolerances for structural bolting
EN 1090 execution classes (EXC1 to EXC4) set the tolerance a fabricator must hold; most commercial building steelwork is EXC2. Standard clearance holes for M16-M24 structural bolts are the bolt diameter plus 2 mm, laser or drilled to ±0.3 mm position accuracy so multi-hole patterns line up with the connecting member across a splice.
Plate flatness matters as much as hole position: plate over 20 mm thick can carry mill camber that shows up after cutting. CutLinq checks flatness before drilling and flags plate that will not sit square without correction.
| Bolt size | Standard clearance hole | Hole position tolerance | Execution class |
|---|---|---|---|
| M16 | 18 mm | ±0.3 mm | EXC2 |
| M20 | 22 mm | ±0.3 mm | EXC2 |
| M24 | 26 mm | ±0.5 mm | EXC2 |
| M16-M24, slotted | bolt dia + 4 to 6 mm | ±0.5 mm | EXC2, movement joints |
Welding and NDT for structural connections
Fillet and butt welds on load-bearing connections are made to ISO 5817 acceptance level C or B as specified on the drawing, with visual inspection standard on every weld and dye penetrant or ultrasonic testing on full-penetration welds when the specification calls for it. Preheat is applied on S355J2 above 25 mm thickness to avoid hydrogen cracking, particularly relevant on cold winter mornings in the Saudi interior.
Weld procedure qualification records and welder certificates are held by suppliers in the CutLinq network for structural work; ask for these documents at order time if your project specification requires them.
Corrosion protection for exterior structural steel
Interior structural steel usually needs only a primer coat, but exterior steelwork in coastal Jeddah, Abu Dhabi or Alexandria needs hot-dip galvanising to ISO 1461 or a duplex system (galvanising plus polyester powder or epoxy topcoat) for both corrosion resistance and architectural colour. Galvanising bath size limits the length of a single dipped stringer or plate, typically 6-12 metres depending on the facility, so long members may need a splice joint designed in.
Design tips
- Specify execution class (EXC1-EXC4) per EN 1090 on the drawing so the fabricator applies the correct tolerance and documentation.
- Standard clearance hole = bolt diameter + 2 mm; use slotted holes only where drawing shows a movement or tolerance joint.
- Keep edge distance from any hole to plate edge at least 1.5x bolt diameter to avoid tear-out under load.
- For galvanised assemblies, add 6-8 mm vent and drain holes to hollow sections before galvanising to prevent explosion in the zinc bath.
- Design splice plates with 2-3 mm gap at butt joints so laser-cut tolerance stack-up does not prevent fit-up on site.
- State weld acceptance level (ISO 5817 B or C) per joint on the drawing, not as a single blanket note.
- Group base plates and gussets by grade and thickness in one nesting file to reduce per-part laser cost.
Applications
| Industry | Example parts | Typical material |
|---|---|---|
| Commercial buildings | Base plates, gussets, splice plates | S235JR, S355J2 8-40 mm |
| Warehouses and industrial sheds | Column bases, purlin cleats | S235JR 6-16 mm |
| Stairs and mezzanines | Stringers, treads, handrail brackets | S235JR 8-12 mm, checker plate |
| Bridges and infrastructure | Bearing plates, stiffeners | S355J2 16-40 mm |
| Solar and utility structures | Foundation plates, bracing gussets | S235JR galvanised 6-12 mm |
| Facade support | Bracket plates, fixing cleats | S235JR / 304 stainless 6-10 mm |
Pricing and lead time
Cost is set by plate thickness and cutting process (plasma is cheaper than laser above 20 mm but laser holds tighter hole tolerance), by the number of drilled or laser-pierced holes per plate, and by finishing (hot-dip galvanising is priced per batch and is more economical when several plates are combined). Laser-cut and drilled connection plates without finishing are typically ready in 3-6 working days; hot-dip galvanised structural steelwork 8-12 working days across Egypt, the UAE and Saudi Arabia.
Frequently asked questions
Yes, plate above 25 mm is cut by plasma or waterjet and then drilled on a CNC machine to ±0.3-0.5 mm hole position depending on execution class, which laser alone cannot guarantee at that thickness.
Upload your DXF or STEP file with grade, execution class and finish noted, and receive a binding quote within 12 hours.