MATERIALS
Mild Steel grating load bars are manufactured from steel that complies with AS/NZS 3679.1:2010 grade 300 (or equivalent)

TOP SURFACE

Typically supplied with a plain surface. On our most popular products a Serrated surface (S) is also available. Please refer to the loading charts in this section of the catalogue to see which Mild Steel grating types are available with a Serrated surface.
 

• The "S" at the end of the code represents a Serrated surface, no notation represents a plain surface. Grating will be assumed plain surface unless S is dictated at the end of the product code or is clearly specified as Serrated. Eg- 255/1S or 255/1 Serrated

EXAMPLE OF A SERRATED SURFACE PRODUCT CODE:
325/2S = 32x5mm load bars at 40mm centres, cross bars at 100mm centres (Serrated surface)

EXAMPLE OF PLAIN SURFACE PRODUCT CODE:
255/1 = 25x5mm load bars at 30mm centres, cross bars at 100mm centres (plain surface)

FINISH

• Black (untreated/raw) finish (U)
• Hot dip galvanised finish to meet the requirements of AS/NZS 4680 (G)
• Powder coated finish (P)

STANDARD SHEET SIZE
Series 1 grating: 995mm (wide) x 5800mm (span)
Series 2 grating: 1005mm (wide) x 5800mm (span)
Series 3 grating: 965mm (wide) x 5800mm (span)
*Standard panel widths may vary slightly to what is indicated as there are minor manufacturing tolerances allowable during the process of manufacturing grating.
*Sizes above state grating manufactured from 5mm load bars (for 3mm load bar full panel width please -2mm off the sizes eg- 993mm wide for series 1 and 1003mm wide for series 2).

HOW TO SPECIFY / ORDER MILD STEEL GRATING

• Use the quick reference load charts or the main load charts to determine a suitable load bar size and series to suit your loading requirements. Eg- 255/1 or 325/2 etc...
• Designate at the end of the code with an S if you require a Serrated surface, No designation will be assumed a Plain surface.

*check which grating options are available with a serrated surface within the load charts

• Designate that the product you require is Mild Steel by referencing M = Mild Steel grating
• Designate the finish you require:
  • U = Black (untreated / raw finish)
  • G= Hot dip galvanised to AS/NZS 4680
  • P = Powder coated finish

• Specify the size of the area or panel size(s) for the grating you require along with the load bar direction (span)
• Specify any additional information we need to know for example if there are cut outs or penetrations in the grating, do we need to split cut outs between panels for installation, is kick plate required, are the grates banded or cut to size only etc....

EXAMPLES OF ORDERING / SPECIFYING MILD STEEL GRATING

405/ 1 MU = 40x5mm plain load bars (series 1 grating, load bars at 30mm centres, cross bars at 100mm centres) Mild Steel, Untreated finish
325/2S MG = 32x5mm Serrated load bars (series 2, load bars at 40mm centres, cross bars at 100mm centres) Mild Steel, Galvanised finish.

(1) 2.5 kPa, 5mm deflection- Light use for access and working, AS 1657
(2) 4 kPa, 5mm deflection- High / Repetitive use, AS/NZS 1170
(3) 5 kPa, 5mm deflection – High / Repetitive use with placement of objects and tools (infrequent), AS/NZS 1170
(4) 7.5 kPa, 5mm deflection – High / Repetitive use with placement of objects and tools (frequent), AS/NZS 1170
(5) *product is low use (held in small quantities or not commonly stocked) please contact Steel Grating Ltd for information on quantities regarding these items

SAFE LOAD AND DEFLECTION TABLE

(1)The data provided in the above table based on the critical design case of the Allowable Stress Design and the Ultimate Limit State Design. The Mild steel is Grade 300 with a yielding strength of 320 MPa according to AS3679-2006, the allowable design stress is 211 MPa.
(2) U: Safe Superimposed Uniformly Distributed Load – kPa
(3) D: Deflection due to the Safe Superimposed Load – mm
(4) D4: Deflection due to 4 kPa applied load – mm
(5) Span shown to the left of the heavy line have a deflection of less than 5mm for a 4kPa UDL
(6) Add 12% to the mass provided for galvanising and fabrication banding bars

SAFE LOAD AND DEFLECTION TABLE

SAFE LOAD AND DEFLECTION TABLE

(1)The data provided in the above table based on the critical design case of the Allowable Stress Design and the Ultimate Limit State Design. The Mild steel is Grade 300 with a yielding strength of 320 MPa according to AS3679-2006, the allowable design stress is 211 MPa.
(2) U: Safe Superimposed Uniformly Distributed Load – kPa
(3) D: Deflection due to the Safe Superimposed Load – mm
(4) D4: Deflection due to 4 kPa applied load – mm
(5) Span shown to the left of the heavy line have a deflection of less than 5mm for a 4kPa UDL
(6) Add 14% to the mass provided for galvanising and fabrication banding bars
(7) Series 3 grating does not comply with the requirements of AS 1657 due to the openings exceeding the limits stated in AS1657 design criteria.

(8) *Product is low use (held in small quantities or not commonly stocked) please contact Steel Grating Ltd for information on quantities regarding these items

INSTALLATION DETAIL FOR MILD STEEL GRATING

GALVANISED FIXING CLIPS

Steel Grating Ltd provides a universal fixing clip designed to suit our series 1, series 2 and series 3 Mild Steel grating options with the load bar sizes from 20mm up to 50mm. These clips comprise of a top "M"clip designed to saddle over the top of the grating and a bottom "J"clip that when applicable is designed to fasten the underside of the grating to the support. The bottom clip captivates the nut meaning that fastening the grating to the supports can be done from the top side of the grating for ease of installation.

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• 4 fixing clips per m2 is recommended with additional clips to be used on longer grates at the intermediate spans.
• Minimum 4 clips per panel is recommended.

*In areas of lateral load movement or vibration fixing clips are not generally recommended.

WELDING GRATING TO ITS SUPPORT
Welding grating to the supporting structure is deemed a suitable process for permanently installed grating or in areas of vibration and lateral load movement. Steel Grating recommends a 25mm long, 6mm fillet weld at  1000mm centres. Minimum number of welds per panel is 4.

WELDING FIXING LUGS TO GRATING
Fixing lugs can be provided on grates if necessary. This comprises of a flat bar welded between the load bars with a hole drilled in it. The fixing lug is usually located flush with the bottom side of the grating and the centres of the holes for the fixing lugs are determined by the spacings of the load bars.

ADDITIONAL INFORMATION

MINIMUM SUPPORT DIMENSION

• A minimum support of 25mm for grating up to 50mm deep.
• A minimum support of 50mm for 50mm and 65mm deep grating.

It is generally recommended that the minimum grating support should be equal to the height of the grating load bar.

RECOMMENDED CLEARANCES
• 5mm (min) to 10mm (max) spacing between grates.
• 10mm clearance of grating from the edge of a wall or end of a support
• When grating sits in an angle minimum recommended clearance each side is equal to the thickness of the angle.