Specifications include, but are not limited to: Category 1: Cutting Edges for Truck Mounted Snowplows. Subcategory A: Standard Snowplow Cutting Edges: To be constructed from a high carbon alloy steel (AISI 1084 – C1090) and have a hardness rate greater than 25 on the Rockwell Hardness “C” Scale Shall be supplied in lengths of 3 feet through 8 feet and bid at a cost per foot. Cutting edges shall be supplied in the following size: ½ inch thick x 6 inches wide ½ inch thick x 8 inches wide 3/4 inch thick x 6 inches wide 3/4 inch thick x 8 inches wide Subcategory B: Special Through Hardened Snowplow Cutting Edges: To be constructed of high carbon alloy steel (AISI 1084 – C1090) and have a hardness rating greater than 45 on the Rockwell hardness “C” scale. Cutting edges shall be supplied in the following sizes: Each size will be offered in various lengths, ranging from 3 feet to 14 feet. 5/8 inch thick x 6 inches wide 5/8 inch thick x 8 inches wide ¾ inch thick x 6 inches wide ¾ inch thick x 8 inches wide Subcategory C: Cutting Edges with Carbide Insert: 1. Blade The blade shall be flat hot-rolled finished steel to meet or exceed specifications for A36 or 1020 type steels. The groove for the carbide inserts shall be milled in the center of the blade edge. The center of the bolt holes shall be in line within 1/32 inch of established horizontal centerline and 1/16 inch of established vertical centerline. Cutting edges to be supplied in 2-, 3- and 4-feet lengths. Cutting Edges to be supplied in sizes of ¾ inch thick x 6 inches wide and 7/8 inch thick x 5 inches wide. 2. Tungsten Carbide Inserts The inserts shall be a high shock WC grade of tungsten carbide with 11 to 12.5 percent cobalt content. Hardness: 87.5 minimum to 89.0 Maximum Rc. “A” scale. Transverse rupture strength (p.s.i.): 350,000 Minimum. Porosity: (Based on testing in accordance with ASTM designation B276-79) A06 B02 C00 The carbide insert manufacturer to furnish certification to WSDOT that the inserts meet the specifications as set forth in section an immediately above. The inserts shall be a trapezoid design of the following dimensions: Height: .635” +/- .005 (long side) Width: .365” +/- .010 Length: 1” Nominal Bottom Angle: 25 Degrees with a nose radius of 1/16” minimum A metallurgical evaluation of the carbide insert shall show no evidence of cross grade contamination. Evaluation to be based on a photomicrograph of a polished and etched specimen at 500x magnification. 3. Brazing The brazing material shall be a high strength alloy type. The tungsten carbide inserts shall be positioned in the milled groove at approximately .010” between the inserts the entire length of each cutting edge section. The inserts shall be brazed on all sides consistent with sound brazing practice with no evidence of voids or use of shims. Each blade section to contain one insert for each inch of blade section. Due to the thickness of the braze joints between inserts it may be necessary for several inserts to be slightly shorter or no longer than the nominal 1” length to ensure the carbide insert runs the entire length of the blade without protruding from the end of the steel body. 4. General The difference between the highest and lowest tip point (on any two adjacent inserts) not to exceed 1/32” on any given blade assembly. The finished blade section shall be free of any warpage and longitudinal deviation not to exceed 1/8” in a four-foot blade section. Each blade section shall be identified with manufacturer’s identification stamp. The finished blade sections shall have markings showing the front edge of the blade to avoid improper mounting. Category 2: Grader Cutting Edges: Subcategory A: Standard grader cutting edges: To be constructed from a high carbon alloy (AISI 1084 – 1090) steel and have a hardness rate equal to or greater than 25/35 on the Rockwell Hardness “C” Scale. To be supplied in length of 3 feet through 8 feet and bid at a cost per foot. Shall provide double bevel flat cutting edges with the following dimensions: ½ inch thick x 6 inches wide 5/8 inch thick x 6 inches wide ¾ inch thick x 6 inches wide ¾ inch thick x 8 inches wide To provide singe bevel curved cutting edges in the following dimensions: ½ inch thick x 8 inches wide 5/8 inch thick x 6 inches wide ¾ inch thick x 6 inches wide ¾ inch thick x 8 inches wide To provide double bevel curved cutting edges with the following dimensions: ½ inch thick x 6 inches wide ½ inch thick x 8 inches wide 5/8 inch thick x 6 inches wide 5/8 inch thick x 8 inches wide ¾ inch thick x 8 inches wide To provide serrated cutting edges with a serration of 4.5 inches, 1-inch tooth width, 1.4 inches between the teeth and a 30-degree tooth angle for edges with angle teeth. In the following dimension: ¾ inch thick x 8 inches wide left angle teeth ¾ inch thick x 8 inches wide right angle teeth Subcategory B: Special Through Hardened Grader Cutting Edges: To be constructed from a high carbon alloy (AISI 1084 – C1090) steel and have a hardness rate equal to or greater than 452 on the Rockwell Hardness “C” Scale. To be supplied in length of 3 feet through 8 feet and bid at a cost per foot. Shall provide double bevel flat cutting edges with the following dimensions: ½ inch thick x 6 inches wide 5/8 inch thick x 6 inches wide ¾ inch thick x 6 inches wide ¾ inch thick x 8 inches wide To provide singe bevel curved cutting edges in the following dimensions: ½ inch thick x 8 inches wide 5/8 inch thick x 6 inches wide ¾ inch thick x 6 inches wide ¾ inch thick x 8 inches wide To provide double bevel curved cutting edges with the following dimensions: ½ inch thick x 6 inches wide ½ inch thick x 8 inches wide 5/8 inch thick x 6 inches wide 5/8 inch thick x 8 inches wide ¾ inch thick x 8 inches wide To provide serrated cutting edges with a serration of 4.5 inches, 1-inch tooth width, 1.4 inches between the teeth and a 30-degree tooth angle for edges with angle teeth. In the following dimension: ¾ inch thick x 8 inches wide left angle teeth ¾ inch thick x 8 inches wide right angle teeth Category 3: Rubber cutting edges: Rubber cutting edges to be constructed from material that conforms to ASTM D2000 – SAE J200 (grade 625, duro 60, tensile strength 2500 psi and low temperature –40 F) All edges to be reversible. All edges to have slotted 11/16-inch mounting holes. All edges to be provided in lengths of 5 feet through 12 feet. All edges to be 1 ½ inches thick. Rubber Cutting Edges with Standard Highway Slots and Special Slots (if available) shall be provided. Rubber edges shall be provide in the following widths: 10 inches 12 inches
