Premier Global Industry
Premier Global Industry
Premier Global Industry

Standard & Specification For The U.S.
Municipal Drainage & Construction Castings

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  • ASTM A48, ASTM A536

Material

Grey Iron castings shall conform to ASTM A48-2003 (A48M) Class 35B, AASHTO M105, and/or AASHTO-M306 unless otherwise specified. Ductile Iron castings shall conform to ASTM A536-84(2004) and A536 Grade 80-55-06. Castings shall conform to ASTM A48 Class 30/35B Or ASTM A 536.

Manufacturing

Castings supply will be free from pouring faults, shrinkage, cracks, cold shuts, sponginess, blow-holes, and other defects. Bearing surfaces shall be machined, if necessary, so that the grates and covers sit firmly on the frames without rocking. The cover or grate shall not rock when rotated to any position in the frame. Circular manhole frames, covers, and grates shall be furnished with machined horizontal bearing surfaces unless otherwise specified. All square and rectangular units shall be furnished with an as-cast bearing surface unless otherwise specified.

Tolerances

As cast dimensions may vary by ± 1/16 inch per foot in critical areas relating to fit, load bearing capacity and drainage openings.
Dimension Tolerances:

  • a) 300 mm or less +/- 3 mm
  • b) Up to and including 900 mm +/- 6mm
Non-critical dimensions may be modified to facilitate proper casting techniques, performance and value, without notice. Notwithstanding these tolerances, all rings, covers, frames, grates and curb hoods of the same nominal size are interchangeable.

Weights

Casting weights shall be within ± 5% of the specified weight and/or as shown on customer drawing.

Paint

Castings are supplied unpainted as a standard, unless specified. If paint is required, all surfaces shall be painted with one shop coat of asphalt or at base black paint having a minimum softening point of 71 degree centigrade. All joints and crevices shall be thoroughly coated.

Cast Iron Load Rating

All castings to have load tested in accordance with the destructive testing protocol below, and are assigned one of the following four load rating designations:

  • Non-Traffic: These castings are intended for areas such as sidewalks, terraces and other areas not subject to vehicular traffic loads.
  • Medium Duty: Castings bearing this designation are able to withstand occasional vehicular loading, but are not intended to receive heavy highway traffic. Applications include driveways, parking lots, and ramps.
  • Heavy Duty: These castings are manufactured to withstand highway traffic loads, exceeding AASHTO H-20/HS-20 specifications (wheel loads of 16,000 pounds with a tire contact area of 10” x 20”) 25,000 pounds proof load in accordance with CID A-A 60005 or 40,000 pounds proof load per AASHTO M-306.

Quality Assurance

Upon request, two type ‘C’ test bars for each lot of castings as described in ASTM A48 shall be supplied. Failure of the test bars to meet the specified tension requirements will be reported within two weeks from receipt of the test bars.

Manufacturing

Castings supply will be free from pouring faults, shrinkage, cracks, cold shuts, sponginess, blow-holes, and other defects. Bearing surfaces shall be machined, if necessary, so that the grates and covers sit firmly on the frames without rocking. The cover or grate shall not rock when rotated to any position in the frame. Circular manhole frames, covers, and grates shall be furnished with machined horizontal bearing surfaces unless otherwise specified. All square and rectangular units shall be furnished with an as-cast bearing surface unless otherwise specified.