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Cobalt S&D Reduced Shank Drill Bit

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Cobalt S&D drill bits expands the size range capacity of a 1/2" portable drill chuck. Common flute and overall length for minimal adjustment during tool changes. Precision ground for high degree of concentricity between shank and body diameter. Ideal for drilling in tough, high tensile strength materials. The 135º split point reduces thrust and eliminates walking at the drill point.

Products

Dimensional Specifications

Size Decimal
Equivalent		 Flute
Length		 Overall
Length
33/64 0.5156 3 6
17/32 0.5313 3 6
35/64 0.5469 3 6
9/16 0.5625 3 6
37/64 0.5781 3 6
19/32 0.5938 3 6
39/64 0.6094 3 6
5/8 0.6250 3 6
41/64 0.6406 3 6
21/32 0.6563 3 6
43/64 0.6719 3 6
11/16 0.6875 3 6
45/64 0.7031 3 6
23/32 0.7188 3 6
47/64 0.7344 3 6
3/4 0.7500 3 6
49/64 0.7656 3 6
25/32 0.7813 3 6
51/64 0.7969 3 6
13/16 0.8125 3 6
53/64 0.8281 3 6
27/32 0.8438 3 6
55/64 0.8594 3 6
7/8 0.8750 3 6
57/64 0.8906 3 6
29/32 0.9063 3 6
59/64 0.9219 3 6
15/16 0.9375 3 6
61/64 0.9531 3 6
31/32 0.9688 3 6
63/64 0.9844 3 6
1 1.0000 3 6
1 1/32 1.0313 3 6
1 1/16 1.0625 3 6
1 3/32 1.0938 3 6
1 1/8 1.1250 3 6
1 5/32 1.1563 3 6
1 3/16 1.1875 3 6
1 7/32 1.2188 3 6
1 1/4 1.2500 3 6
1 9/32 1.2813 3 6
1 5/16 1.3125 3 6
1 11/32 1.3438 3 6
1 3/8 1.3750 3 6
1 13/32 1.4063 3 6
1 7/16 1.4375 3 6
1 15/32 1.4688 3 6
1 1/2 1.5000 3 6
  1. All dimensions are in inches.

Drill Feeds & Speeds

Material Hardness Drill Type Point Style Point
Angle		 Speed
(SFM)		 Feed Coolant
Aluminum / Aluminum Alloys - High Helix Standard 118° 200-300 Medium to Heavy Water Soluble
Aluminum Bronze - High Helix Standard 118° 50-100 Medium to Heavy Water Soluble
Brass, Free Machining - Low Helix Standard 118° 100-250 Medium to Heavy Water Soluble
Bronze, Soft Medium Below 200 General Purpose Standard 118° 70-150 Medium to Heavy Water Soluble
Bronze, High Tensile - Low Helix or Half RD Standard 118° 50-100 Medium to Heavy Water Soluble
Copper / Copper Alloys - General Purpose Standard 118° 100-200 Medium Water Soluble
High Temp Alloys, Cobalt Base 180-300 Cobalt Split Point 135° 5-20 Medium Activated Oils
High Temp Alloys, Iron Base 180-300 Cobalt Split Point 135° 5-20 Medium Activated Oils
High Temp Alloys, Nickel Base 180-300 Nitro® or Cobalt Split Point 135° 5-15 Medium Activated Oils
Iron, Soft Case Up to 150 Heavy Duty or Nitro® Split Point 135° 75-150 Medium Dry / Air
Iron, Medium Case 150-250 Heavy Duty or Nitro® Split Point 135° 50-100 Medium Dry / Air
Iron, Hard Case Over 250 Carbide Standard 118° 40-75 Light to Medium Dry / Air
Plastic & Related Materials - Low Helix Low Angle 90° 100-200 Medium to Heavy Dry / Air
Steel, Low Carbon Alloy 125-275 General Purpose Standard 118° 50-70 Medium Water Soluble
Steel, Medium Carbon Alloy 275-325 Heavy Duty or Nitro® Split Point 135° 40-55 Medium Water Soluble
Steel, High Carbon Alloy Over 325 Cobalt Split Point 135° 30-50 Medium Water Soluble
Steel, Low & Medium Carbon Alloy Below 175 General Purpose Standard 118° 45-95 Medium to Heavy Water Soluble
Steel, High Carbon Alloy 175-225 General Purpose Standard 118° 45-65 Medium Water Soluble
Stainless Steel, Austenitic Below 300 Heavy Duty or Nitro® Split Point 135° 40-60 Medium to Heavy Water Soluble
Stainless Steel, Precipitation Over 300 Cobalt Split Point 135° 20-40 Medium Cutting Oil
  1. Feeds – Feed rates for drilling are governed by the drill diameter, machinability of materials and depth of hole.
  2. Speeds – The speed of a drill is determined by the rate which the outer periphery of the tool rotates in relation to material being cut. In general, the SFM at which a drill will operate is within a range based upon the workpiece material, its condition, hardness and depth of hole. It is usually advisable to start the drilling process at a slower SFM and then increase to the maximum.
  3. RPM = (SFM x 3.82) divided by TD = Revolutions Per Minute
  4. SFM = RPM x TD x .262 = Surface Feet Per Minute
  5. TD – Tool diameter in inches