Click for larger image and other views Image is representative of the product family. Select individual products in the table below for more specific images and product specifications

How can we improve our images or Product Specifications?

Precision Twist R56CO Cobalt Steel Reduced Shank Drill Bit, Black and Gold Oxide Finish, 1/2" Reduced Shank, 118 Degree Split Point

Be the first to review this item

Product Specifications
Cutting Direction
Right-Hand
Finish Types
Gold Oxide
Shank Type
Round
Material Type
Cobalt Steel
Drill Point
Split
UNSPSC Code
20121600
Cutting Angle
118  Degrees
Brand Name
Precision Twist
Flute Type
Spiral

This item is no longer available

These items ship for FREE with 2-Day Shipping on orders over $50. (Details)

Want it delivered on Mon, Oct 27? Order in-stock items in the next 3 hrs 43 mins and choose One-Day Shipping at checkout.

  • Share
Currently showing 1-20 of 32 Next 12 »
Size Mfg Series # System of Measurement Flute Length Overall Length Pkg Qty Mfr Part # ASIN

The Amazon Standard Item Number (ASIN) uniquely identifies
the item in the AmazonSupply.com (and Amazon) catalog.

Available

If an item is currently out of stock, but has an estimated lead time, you can place an order now and we will ship it as soon as it is available.
You can also order more than we currently have in stock.
Read more about back orders in our help section.

Price  
All All All All All All      
Currently showing 1-20 of 32 Next 12 »
33/64" R56CO Inch 3" 6" 1 92333 B002097HQ4 yes $12.45 Buy Options
17/32" R56CO Inch 3" 6" 1 92334 B00075R7AY yes $43.67 Buy Options
35/64" R56CO Inch 3" 6" 1 92335 B003JTIIZI yes $30.72 Buy Options
9/16" R56CO Inch 3" 6" 1 92336 B00075R7BI yes $29.87 Buy Options
37/64" R56CO Inch 3" 6" 1 92337 B002091Z3U yes $49.93 Buy Options
19/32" R56CO Inch 3" 6" 1 92338 B00075R7C2 yes $48.77 Buy Options
39/64" R56CO Inch 3" 6" 1 92339 B002KNM42W yes $10.73 Buy Options
5/8" R56CO Inch 3" 6" 1 92340 B003JTIJ1G yes $54.35 Buy Options
41/64" R56CO Inch 3" 6" 1 92341 B003JTIIZS yes $34.01 Buy Options
21/32" R56CO Inch 3" 6" 1 92342 B003JTIIYE yes $33.72 Buy Options
43/64" R56CO Inch 3" 6" 1 92343 B003JTIJ02 yes $36.47 Buy Options
11/16" R56CO Inch 3" 6" 1 92344 B00075R7F4 Usually ships in 2 to 5 weeks $52.46 Buy Options
45/64" R56CO Inch 3" 6" 1 92345 B003JTIJ0C yes $37.46 Buy Options
23/32" R56CO Inch 3" 6" 1 92346 B003JTIIYO yes $12.22 Buy Options
47/64" R56CO Inch 3" 6" 1 92347 B003JTIJ0M yes $40.23 Buy Options
3/4" R56CO Inch 3" 6" 1 92348 B00075R7G8 yes $61.19 Buy Options
49/64" R56CO Inch 3" 6" 1 92349 B003JTIJ0W yes $24.97 Buy Options
25/32" R56CO Inch 3" 6" 1 92350 B003JTIIYY yes $39.91 Buy Options
51/64" R56CO Inch 3" 6" 1 92351 B002KNG4MS yes $17.24 Buy Options
13/16" R56CO Inch 3" 6" 1 92352 B001VXU690 yes $43.26 Buy Options

Key Features

  • High-speed steel (HSS) containing cobalt is a good combination of toughness and hardness, for use on drilling through hard substances
  • Combination black oxide and gold finish, improves lubricity, resists corrosion, and will not chip or flake off
  • Half-inch round shank allows larger sized drills to fit into small size chucks
  • Jobber-length drill bits, most common length drill bit, suitable for a wide range of applications
  • 118-degree split-point angles, for general drilling applications

Product Description

The Precision Twist R56CO Jobber-length, combination black (also called steam tempered) and gold oxide, general-purpose, round shank drill bit drills holes into a wide variety of metals and synthetic materials with best performance with steel, stainless steel, cast iron, titanium, nickel, and copper. It can drill to a depth up to four times the diameter of the drill size. Flute length is three inches, overall length is six inches, with a half-inch, reduced shank.

The R56CO series has a type N flute form (a regular helix angle of 21 to 34 degrees). The combination black oxide and gold finish improves lubricity, resists corrosion, and will not chip or flake off. Black and gold oxide is an appealing surface treatment which combines the benefits of both black oxide and gold oxide. Black oxide finish gives a strongly adhering blue oxide surface that acts to retain cutting fluid and prevent chip to tool welding, reducing the formation of a built-up edge. Gold oxide is a low temperature heat treatment which reduces grinding stress within the tool, and has an appealing, easy-to-identify gold color. Gold oxide is commonly used to identify cobalt steel tools.

Reduced shanks are smaller than the drill diameter, so they can drill holes larger than the typical chuck capacity. These are sometimes called Silver & Deming drills; they used to be made by Silver & Deming in the late 1800s, but now it refers to any reduced shank twist drill bit.

Made of HSS with cobalt which is many times harder/stiffer than HSS, will hold an edge longer, and will deflect less than HSS. These are also more resistant to heat than HSS. These qualities allow it to run at higher speeds and feeds. They are made to ANSI (fractional sizing) industry standards, which ensure that drill bits around the world, conform to the same specifications.

Drilling, or hole making, is the most common metalworking operation in the world. Twist drill bits are the most common type of drill bit used. Twist drill bits are commonly used to drill holes with hand-operated drills, standalone drill presses, or lathes. The flutes of the drill bit act a passageway for chip extraction from the hole and for coolant to enter the hole. These drill bits have a right-hand twist that brings chips up and away from the cutting edge.

Precision manufactures machine tools under the following brands: Precision Twist, Precision Dormer, and Union Butterfield. They have locations around the world, and provide tools adhering to ANSI, NAS, and DIN standards.

How can we improve our Product Description?

Customer Reviews

There are no customer reviews yet.

Be the first to review this item

Go to the HomePage

Order by Phone
M-F 8am-8pm ET, Sat-Sun 8am-5pm ET 800-220-4242

My Account| Returns| Help

Website Feedback| Contact Us| Sell on AmazonSupply| Become an Affiliate

Privacy Notice| Conditions of Use

Follow Us 

© 2014 Amazon.com, Inc. and its affiliates.