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McNichols Technical Support Center

Load tables, specification guides, ASTM standards references, and answers to the questions our engineers get every day.

Bar Grating Load Tables

ANSI/NAAMM MBG 531 compliant load tables for standard bearing bar sizes. Covers uniform and concentrated loads, deflection limits, and span recommendations.

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ASTM & Standards Reference

Key ASTM standards used in McNichols products: A36, A1011, A240, A276, B209. Summaries of chemical and mechanical property requirements.

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Mill Test Reports (CMTR)

Every order can ship with a certified mill test report. Critical for public infrastructure, government projects, and ASME-regulated applications. Request at time of order.

Request with Order

FRP Chemical Resistance

Fiberglass grating resistance tables for common industrial chemicals: sulfuric acid, caustic soda, chlorine, and more. Available for ISO VE and Phenolic resins.

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Can't find what you need? Call our engineers.

Mon–Fri 7:30 AM – 6:00 PM EST · 1-844-645-6200 ext. 2

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Frequently Asked Technical Questions

What is the difference between welded and press-locked bar grating?

Welded bar grating has cross bars resistance-welded to the bearing bars, creating a permanent bond. Press-locked grating has cross bars mechanically interlocked into slots cut in the bearing bars — no welding required. Press-locked is preferred where smooth top surface appearance is critical. Welded is generally more economical and more widely stocked. Both types meet ANSI/NAAMM MBG 531 when specified accordingly.

How do I interpret bearing bar size designations?

Bearing bar dimensions are expressed as Height × Width (H × W). A "1-3/16 × 3/16" bar is 1-3/16 inches tall and 3/16 inches thick. Taller bearing bars carry greater loads at longer spans. Cross bar spacing (typically 4-3/16" or 2-3/16" centers) affects the open area percentage and load capacity. McNichols can provide a load table for any specific bar size and span you're working with.

When should I specify fiberglass (FRP) grating instead of steel?

Specify FRP when the environment involves: chemical splash (acids, caustic, chlorine), continuous moisture or seawater exposure, electrical non-conductivity requirements, or weight restrictions where aluminum is too costly. FRP fiberglass grating adds cost per square foot compared to standard carbon steel, but eliminates ongoing galvanizing and repainting costs in corrosive environments. Typical service life in chemical plants is 15–25 years with minimal maintenance.

Can McNichols cut grating to non-standard panel sizes?

Yes. All 19 service centers operate fabrication shops with band saws and shearing equipment. Standard tolerances are ±1/16 inch on cuts. We also perform cut-outs for pipes, columns, and equipment bases. For aluminum and stainless grating, cross bar ends may need to be banded or welded after cutting — specify this in your RFQ. Lead time for cut-to-order panels is typically 1–3 business days from in-stock material.

What does hot-dip galvanizing after fabrication (HDGAF) cost compared to pre-galvanized?

Hot-dip galvanizing after fabrication provides superior corrosion protection because the zinc coating covers all cut edges, welds, and holes — areas left bare when ordering pre-galvanized sheet. HDGAF typically adds 20–35% to base material cost and 5–7 business days of lead time. For coastal and industrial environments with 15+ year design life requirements, the lifecycle cost is almost always lower than painting pre-galvanized panels annually. McNichols offers HDGAF through our certified galvanizing partners.

Do you provide CMTR (Certified Mill Test Reports) with every order?

CMTRs are available on request for all carbon steel, stainless steel, and aluminum products. Most public infrastructure, DOT, and ASME-regulated projects require CMTR documentation. Request at time of order — there is no additional charge for CMTR on standard stocked material. Chain-of-custody documentation is available for critical applications at a small processing fee.

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Our product specialists answer technical questions about grating specifications, load requirements, ASTM standards, and fabrication options.

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