Chapter 5.90
CASTINGS AND METAL FABRICATIONS
Sections:
5.90.030 Structural and miscellaneous steel.
5.90.040 Bolts, nuts and washers.
5.90.060 Cast iron frames and covers.
5.90.080 Aluminum fabrications.
5.90.090 Aluminum isolation coatings.
5.90.010 Description.
Castings and metal fabrications shall be constructed in accordance with the details shown on the plans, standard drawings and as hereinafter specified. The contractor shall install or erect the metal work, remove the temporary construction, including the removal of the old structure or structures if specified, in accordance with the plans, these specifications and the special provisions. [Ord. 2014-2 (Att. § 18-01).]
5.90.020 Materials.
The various materials shall conform to the requirements of the specifications of the ASTM as listed in the following tabulation with certain modifications and additions as specified later in this chapter.
|
MATERIAL |
ASTM DESIGNATION |
|---|---|
|
Structural steel |
A-36 |
|
Structural silicon steel |
A-94 |
|
Structural nickel steel |
A-8 |
|
Low alloy structural steel for welding |
A-242 |
|
Structural steel for welding |
A-373 |
|
High-strength structural rivet steel |
A-502 |
|
Bolts and nuts |
A-307 |
|
Black steel pipe (std. wt. seamless) |
A-120 |
|
Carbon steel for forgings |
A-235, Class C1 |
|
Alloy steel for forgings |
A-237, Class A |
|
Cast steel |
A-37, Grade 65-35 |
|
Cast iron |
A-48, Class 30 |
|
Malleable iron castings |
A-47, Grade No. 32510 |
|
Bronze castings |
A-22, Class C |
|
Aluminum alloy GS11A-T6 |
A-209 |
|
Stainless steel forgings |
A-473 |
Materials used in the manufacture of corrugated metal pipes shall conform to AASHO Designation M-36.
Where the contractor has been granted permission to substitute rolled stock for forgings, the rolled stock shall meet the physical and chemical requirements for forged steel. [Ord. 2014-2 (Att. § 18-02).]
5.90.030 Structural and miscellaneous steel.
Steel shapes and plates shall be ASTM A-36. Steel pipes shall be ASTM A-501. Anchor bolts shall be ASTM A-307 with hex heads and nuts. Bolt holes in steel shall be one-sixteenth-inch oversize, except for holes in column baseplates which may be three-inch oversize.
Fabrication and erection shall conform to the AISC Specification for the Design, Fabrication and Erection of Structural Steel for Buildings, latest edition. All welding shall conform to the standards of the Structural Welding Code of the American Welding Society and Section 1.17 of the AISC Specification, latest edition. All welders shall be certified by the AWS and approved by the testing agency. [Ord. 2014-2 (Att. § 18-03).]
5.90.040 Bolts, nuts and washers.
Bolts and nuts shall conform to the requirements for regular hexagon bolts and nuts of ANSI B18.2.1 and B18.2.2, respectively. Material shall conform to ASTM A-307. Circular washers for common bolts shall conform to ANSI B27.2, Type A. All bolts, nuts and washers shall be galvanized or Type 316 stainless steel as shown on the plans. [Ord. 2014-2 (Att. § 18-04).]
5.90.050 Galvanizing.
Hot dip galvanize all sheet steel, plain or shaped, in accordance with ASTM A-525, Commercial Class 1.25.
Hot dip galvanize all products fabricated from rolled, pressed, and forged steel shapes, plates, bars and strip one-eighth-inch thick or heavier in accordance with ASTM A-123.
Hot dip galvanize all steel hardware, nuts, bolts, washers, anchors and threaded rods in accordance with ASTM A-153. Nuts shall be sized so that they screw on threaded bolts readily after galvanizing.
Repair damaged galvanizing by heated repair method. Repair materials shall be Galvalloy, or Gal-Viz, or equal. [Ord. 2014-2 (Att. § 18-05).]
5.90.060 Cast iron frames and covers.
Castings shall conform to the shape and dimensions shown on the standard drawings. All castings shall be clean and free from blow or sand holes or defects of any kind.
The cover and its seat in the frame shall be machined so that the cover will sit evenly and firmly in the frame.
Cast iron frames and covers shall be dipped or painted with asphalt which will form a tough, tenacious, nonscaling coating which does not have a tendency to become brittle when cold or sticky when hot. Covers shall be easily removable. [Ord. 2014-2 (Att. § 18-06).]
5.90.070 Metal railings.
Metal railings shall be of standard one-and-one-half-inch galvanized iron pipe, aluminum, or stainless steel, as detailed on the plans. They shall be neatly welded and finished and securely anchored in place in their designated locations. Pin connections shall be used wherever possible. A minimum of field welding shall be made. All steel railings shall be ground smooth and galvanized after fabrication.
The contractor shall provide suitable chains with eyes welded to the end post or rail at one end, and with snap catch and eye at the other end, at entrance to floor openings and wells within and adjacent to the structure. Chains and eyes shall be ground smooth and galvanized after fabrication. [Ord. 2014-2 (Att. § 18-07).]
5.90.080 Aluminum fabrications.
All aluminum handrails, gratings and frames shall be fabricated in a substantial and workmanlike manner. All grating openings shall be banded, and aluminum angle supports shall be installed as necessary for safety. All grating shall be removable. Grating not secured in position by angles shall be provided with standard bolted aluminum clips or fasteners.
After fabrication, all aluminum material shall be given a clear anodized (electro-chemical) finish conforming to NAAM NA-2A designation to a thickness of seven-tenth mils minimum anodized coating.
Where shown, aluminum gratings shall be provided with Type 316 stainless steel hinges and locking hasps. All screws or bolts shall be Type 316 stainless steel. A padlock shall be provided for each lock and grating. The padlock shall be master keyed to the District standard. [Ord. 2014-2 (Att. § 18-08).]
5.90.090 Aluminum isolation coatings.
Aluminum pigmented asphalt paint shall be used for aluminum in contact with other metals.
All aluminum in contact with concrete shall be coated with an approved isolation coating. [Ord. 2014-2 (Att. § 18-09).]
5.90.100 Cutting with torch.
The use of a cutting torch is permissible if the metal being cut is not carrying stress during the operations. The radius of reentrant flame cut fillets shall be as large as possible, but never less than one inch. To determine the net area of members so cut, one-eighth inch shall be deducted from the flame cut edges. Stresses shall not be transmitted through a flame cut surface.
When cutting with a torch, cuts shall be true to line with a maximum deviation of one-sixteenth inch. All burned edges shall be finished by grinding or chipping. The use of the burning torch will be permitted on ends that form compression connections, providing a minimum of one-quarter inch of metal is left to be removed by machining. [Ord. 2014-2 (Att. § 18-10).]
5.90.110 Painting.
All iron and steel surfaces shall be cleaned and painted in accordance with the requirements of Chapter 5.95 SD5MCC. [Ord. 2014-2 (Att. § 18-11).]
5.90.120 Inspection.
All castings and fabrications shall be inspected and approved prior to installation. The acceptance of any material or finished members by the Inspector shall not be a bar to their subsequent rejection, if found defective. Rejected material shall be immediately removed from the site and replaced promptly by the contractor. [Ord. 2014-2 (Att. § 18-12).]