PLOW BLADE – CARBIDE TIP (25° Trapezoid shape) a. Plow blades will be 3/4”x 6” with a center bolt-hole distance of 2” from the top and will be hot-rolled SAE 1020 through 1045 quality steel. b. To be made available in 3-foot and 4-foot sections. c. Hole punching will be 11/16” square and countersunk to receive 5/8” bolts. d. Location and spacing of the hole will be per AASHTO standards for “HEAVY-DUTY” punching. e. Tolerance for bolt-hole location will be 1/32”. f. A groove for the carbide inserts will be milled in the center of the blade edge. 2. CARBIDE BLADE INSERTS a. Inserts will be made of the following materials: i. 87-89% tungsten carbide ii. 11-12% cobalt iii. 1% maximum for all other elements b. Inserts will be 25° trapezoidal with the following nominal dimensions: i. Length: 1” ± 0.005” ii. Thickness: 0.365” ± 0.005” iii. Height: 0.635” ± 0.005” (measured on the long side) iv. Nose Radius: 1/16” c. Inserts will have the following properties: i. Hardness: 88.0-90.5 HRA per ASTM B294-92 ii. Density: 14.4-14.5 g/cc per ASTM 311-08 iii. Porosity: A04 = 0.06%, B02 = 0.02%, C04 = 0.06% per ASTM B276-05e1 iv. Transverse rupture strength of 351,000 psi, minimum. d. All surfaces (internal and external) will be free of cracks and laminations. e. The carbide insert manufacturer is to furnish certification to the South Dakota Department of Transportation (SDDOT) that the inserts meet the specifications. f. The insert manufacturer is also to certify that the inserts meet virgin tungsten carbide quality specifications.
