Specifications for Blades for Snow and Ice Removal.pdf

EDGCU-2020

- Page 1 of 9

Specifications For

Blades – Snow & Ice Removal

General Requirements

1. Cutting edges shall be of four types: flat drag blades, curved hardened grader blades, serrated grader blades (hardened), and flat carbide insert blades. Any variation in these requirements shall be noted under the various descriptions.

2. Blade thickness tolerances shall be –0.020” and +0.040”

3. Blade length tolerances shall be +0.000” and –0.125”

4. Hole spacing dimensional tolerances shall be 0.0625” non-accumulative as shown in the illustrated attached Drawing A.

5. 11/16” (0.688”) Countersunk square holes shall meet the requirements of SAE standard J740 for 5/8”, No. 3 Head-Plow bolts. Drawing A

6. Camber tolerances: Maximum camber shall not exceed 1/8” for all lengths 0.0 ft through

6.0 ft, 3/16” for all lengths over 6.0 ft. through 10.0 ft. and 1/4” for all lengths over 10.0 ft.

7. Blade ends shall be square and cleanly cut.

8. Blades shall be free from injurious defects.

9. Blade faces shall be clean and free from pits, loose mil scale and rust.

10. Coating: Each blade shall be given one coat of rust resistant paint.

11. Mill test reports (original) shall accompany each blade shipment and shall include all chemical and physical test analysis of each heat number and shall be certified and signed by the producing mill.

12. Each blade shall be uniform in thickness and in width.

13. All grader and serrated blades must be packaged in bundles with the concave faces down so moisture will not be accumulated and be retained in the curvature.

14. Sampling and Testing: A minimum of three (3) samples shall be secured and tested at random by the Iowa Department of Transportation.

Flat Drag Blade Blades shall be flat and may be chamfered on the backside of the upper edge and shall be neither polished nor sharpened. Blades shall be 1/2” thick by 6” wide.

1. Chemical Composition:

Chemical composition of the metal of the blades shall have the following elements

Element Percent Minimum Maximum

Carbon 0.80 1.00 Manganese 0.50 0.90 Sulfur 0.05 Phosphorous 0.05 Silicon 0.30

2. Hardness

A. The average Brinell hardness readings for any heat number of any blade shall not be less than 275 or more than 350.

B. The average of three (3) Brinell hardness readings for any individual blade shall not be less than 260 or more than 370.

C. No spot on any blade shall have a Brinell hardness less than 250 or more than 385.

- Page 2 of 9

Curved Hardened Grader Blade (Curved Blade) Grader blades shall be concave toward the front and chamfered on both edges on the back.

Grader Blades shall be flame or through hardened.

1. Dimensions:

A. Grader blades shall be 3/4” thick and 8” wide.

B. Chamfer width shall not be less than 5/8” and no more than 1-3/16”.

C. Thickness of the chamfered edge shall not be less than 3/32” or more than 0.450”.

(See Drawing B)

2. Chemical Composition:

Blades shall be fabricated from quality hot rolled steel bars meeting the requirements of AISI/SAE 1074 for flame hardened and 15B30 for through hardened or approved equal.

3. Hardness:

A. Hardness shall be uniform. Blades shall be flame hardened on front and back faces or through hardened.

B. Flame hardened blades shall be hardened to Rockwell C 625 for a width of 3- 1/2 “ and a minimum depth of 1/8”.

C. Through hardened blades shall have a minimum hardness of Rockwell C43 or Brinell 400.

4. Markings:

Each blade shall have an identifying mark indicating a flame hardened or through-hardened blade.

Serrated Grader Blades (Hardened) Grader blades shall be concave toward the front and shall be double bevel curved.

Blades shall be through hardened.

1. Dimensions A. Grader blades shall be 3/4” thick and 8” wide.

B. Blade serration shall be as follows:

Tooth length 4 3/8” 1/8” (0.1250”)

Tooth width 1 7/16” 1/16” (0.0625”)

Tooth spacing 2 3/8” 1/16” (0.0625”)

Space between teeth 15/16” 1/16” (0.0625”) (See Drawing C)

2. Chemical Composition A. Blades shall be fabricated from quality hot rolled steel bars meeting the requirements of AISI/SAE 15B30 or approved equal.

B. Hardness: Blades shall have a minimum hardness of Rockwell C43 or Brinell 400.

C. Markings: Each blade shall have an identifying mark indicating a through hardened blade.

Flat Carbide Insert Blades This article of the specification covers the requirements for tungsten-carbide insert snow-plow cutting edge of 3.0 ft. and 4.0 ft. sections.

1. Blades:

A. Blades shall be fabricated from quality hot rolled steel meeting the requirement of

ASTM A36

B. Blades shall be fabricated from 6” x 3/4” (0.750”) flat as shown on Drawing D or 5” x 7/8” (0.875”) flat as shown on Drawing E.

- Page 3 of 9

2. Tungsten-Carbide Inserts:

A. Inserts shall be cemented pure virgin tungsten carbide consisting of 11.0% to 12.5% cobalt content grade. Reclaimed carbide shall not be acceptable.

B. Hardness: Insert hardness shall have a Rockwell “A” minimum of 87.5 and a maximum of 89.0.

C. Density: Insert density shall have a minimum of 14.1 and a maximum of 14.6 grams per cubic centimeter.

D. Rupture strength: The transverse rupture strength of the carbide insert shall not be less than 350,000 psi.

E. Dimensions:

a. Inserts shall be trapezoidal (Drawing D & E) and shall have the following dimension requirements:

Height (Greatest)------------------------------0.635” 0.010”

Width----------------------------------------------0.365” 0.005” Length--------------------------------------------1” nominal

Bottom Angle-----------------------------------25 2 with a nose radius of 1/16” (.0625) minimum

3. Brazing Inserts:

The brazing material shall be of high strength alloy type. The braze shear strength shall be a minimum of 30,000 psi, to withstand the impact loading these blades are subjected to in normal snow removal operations. The tungsten carbide inserts shall be positioned in the milled groove as close as possible to each other for 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.

Inserts removed for inspection shall show complete wetting of the contact surface between the filler material and the carbide. Cracked carbides shall be cause for rejection of a shipment. (See Drawings D & E for Carbide-Insert Cutting Edge Sections).

4. Specific Requirements:

The difference between the highest and lowest tip point shall not exceed 1/32” on any blade section. The finished blade sections shall be free of warping, and longitudinal deviation shall not exceed 1/8” in a 4-foot blade section or 3/32” in a 3-foot blade section. Inserts shall be free of cracks. The finished blade sections shall be given one coat of rust-resistant paint, exclusive of the edge with carbide inserts, which shall be masked prior to painting.

Packaging

A. All cutting edges including carbides shall be banded in bundles of ten with metal strapping. Bundles need to be all the same blades. Do not mix different blades in the same bundle. Bolts in the blade holes will not be acceptable.

B. The carbide-insert sections shall be securely banded to nonrefundable pallets, each with a gross weight not exceeding 2,500 pounds. The carbide blade 3’ & 4’ pallets must meet the requirements of the attached drawings (See Pallet Drawings F & G). A pallet of blades should only have one type/size. Do not mix blades on the same pallet.

C. Pallets must be 2-way entry only. 4-way entry is not acceptable.

- Page 4 of 9

Drawing A – Hole Spacing

3" 3" 12"

3" 3" 12"

1-1/2"

1-1/2"

3" 3" 12"

11/16"

1-1/8"

11/16"

11/16"

1-1/8"

11/16"

3' & 4' - 3/4"x 6" Flat Carbide Blades

3' & 4' - 7/8"x 5" Flat Carbide Blades

8', 11' & 12' - 1/2"x 6" Flat Drag Blade

3" 3" 6" 6"

6"

5"

6"

11/16"

11/16"

11/16"

11/16"

8"

1-1/2"

5'-6'-8' & 9' x 8" Curved Blade

1-5/8"

MT-6/22/16

All Curved Blades (Regular and Serrated)

Flat Carbide Insert Blades

Flat Carbide Insert Blades

- Page 5 of 9

Drawing B – Curved Hardened Grader Blades (Curved Blade)

- Page 6 of 9

DRAWING C SERRATED GRADER BLADES (HARDENED)

4.375" 0.1250"+-

8"

3"

3"

12"

1.4375" 0.0625"

0.9375"

2.375"

0.0625"

0.0625"

11/16" 1-1/8"

1-5/8"

MT-6/22/16

6”

- Page 7 of 9

Drawing D

0.750"

1-1/2"

6"

0.688" Square Hole

25-degrees

0.031" Radius

0.635"

0.0625" Radius

0.365"

- Page 8 of 9

Drawing E

0.406"

1-1/2"

5"

0.688" Square Hole

1"

0.531"

0.875"

0.031" Radius

25-degrees

0.0625" Radius

0.365"

0.635"

- Page 9 of 9

Drawing F – Pallet Drawing

Drawing G – Pallet Drawing