1. 2D/3D Drawings & Dimensional Tolerances

Your fabricator's Heavy Machining and estimating departments require absolute clarity regarding part geometry. While a 3D model explains the shape, the 2D PDF drawing contains the critical, legally binding manufacturing specs.

• Provide Native 3D CAD Files: We highly recommend supplying .STEP or .IGES files. These non-proprietary formats integrate perfectly with Mastercam and our heavy CNC programming software.
• Flat 2D Prints (.PDF/.DWG): A detailed 2D print is mandatory for revealing the Geometrics Dimensioning and Tolerancing (GD&T). Call out precisely which surfaces require micron-level finish milling and which can remain plasma-cut plate.
• Weight & C.G.: Explicitly declare the anticipated total weight and Center of Gravity on your prints—essential for determining crane capacity (up to 250 tons at Openex).

2. Material Selection & Traceability Requirements

Materials drive 30% to 50% of your quote cost. Simply asking for "Carbon Steel" leaves too much to interpretation. You must strictly specify the grades available in our Materials Hub.

Does your component demand highly abrasive operations? Specifically request Wear-Resistant Hardox or AR500 steel. We need to know this instantly, as machining these materials requires significantly longer tooling setup times and hardened end-mills.

3. Welding Codes and WPS Constraints

Not all welds are equal. If you are ordering Offshore Components or large structural beams, explicitly define your regulatory frameworks in the RFQ document.

• Will the product be inspected under AWS D1.1 Structural Code or ASME Section IX (Pressure Vessels)?
• Does the structural design require multi-pass Submerged Arc Welding (SAW) for full penetration, or is robotic Flux-Cored acceptable?
• Can your fabricator develop their own Welding Procedure Specifications (WPS) or will you be supplying locked client specifications?

4. Inspection & NDT (Non-Destructive Testing) Requirements

Heavy equipment operators rely heavily on safety codes. Defining your quality testing requirements limits costly mid-manufacturing arguments regarding pass/fail states on deep weldments.

Ensure you explicitly dictate testing percentages inside the RFQ:

• Radiography (RT): Ex: "10% RT required on all major hull structural seams."
• Ultrasonic (UT): Ex: "100% full-penetration UT required on thick plate flanges."
• Magnetic Particle / Dye Penetrant: Necessary for spotting surface-level stress-cracking.
• Laser Tracker CMM: State whether third-party witnessing of geometric measuring reports is necessary prior to final component delivery.

5. Post-Weld Heat Treatment (PWHT) & Coating

Raw metal fabrication is only phase one. Residual stresses from heavy welding drastically weaken pressure vessels or bridge spans. The RFQ should state if the vendor is responsible for Stress Relieving via large furnace Heat Treatment.

Regarding finishing: Include explicit painting or corrosion defense specs. We must know the exact SA Grit Blasting Standard (e.g. SA2.5 or SA3.0), followed by the total required dry film thickness (DFT) using epoxy or polyurethane.

6. Target Dates & Extreme Shipping Logistics

Transporting a standard pallet across the country is simple. Transporting a 5-meter diameter, 100-ton Tube Sheet across global waters requires monumental supply-chain orchestration and harbor permissions.

Your RFQ must mention your **Incoterm Requirements** (Ex: FOB Shanghai or CIF Los Angeles). Also, establish clear milestone deadlines so fabricators can evaluate capacity on our gantry mills and large turning lathes during those strict scheduling periods.