Countersinks A countersink is a cutting tool which puts a conical hole into an object. A common use is to allow the head of a countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface. Countersinks may also be used to remove burrs left from drilling or tapping operations. Countersinks have been around for many years - from early jewelry making to countersinking detonar holes to be filled with hand grenades during WW1.

Champion offers a variety of high speed steel countersinks for chatter free performance, with smooth and fast chip removal. Countersinks can be used in many tools such as hand held drills or drill presses, milling machines and lathes. They are effective cutting many materials including metal, plastic and wood and are ideal for the glass and window industry. Most Popular Countersink Types

ZERO FLUTE COUNTERSINKS Piloted HSS Champion’s zero-flute countersink is a cross-hole countersink, • Piloted countersinks commonly referred to as a Weldon Style countersink. This is a are recommended for cone shaped tool with a cutting edge provided by a hole that screws from 1/4” to 1/2” diameter. goes through the side of the cone. The intersection of the hole (Round shank - CSK 82º) and cone form the cutting edge of the tool. Pilotless HSS Zero-flute countersinks are best used as deburring tools and • Pilotless countersinks for countersinking softer materials such as aluminum, wood are recommended for or plastic to create a countersunk hole for a screw. bolt sizes from .073 to 1-15/32 and screw sizes #4 Zero countersinks come in 2 styles: Piloted and Pilotless. through #10. (Round shank - DCB 60º, CSK 82º, DBK90º, CSKA100º) (insert here what the pilot does?!?!) (1/4” Hex Shank - CSK-SH)

SINGLE FLUTE COUNTERSINKS • XL801 - Single flute countersink Single flute countersinks are designed for use when multi-flute High hook countersinks chatter or the hole is too small for a multi-flute 60º/82º/90º/100º/120º countersinks to enter. Used for machine and portable work when perating at high speeds. THREE AND FOUR FLUTE COUNTERSINKS • 799 - Three flute countersink As with the single flute countersinks they are designed for 60º/82º/90º/100º/120º chatter free performance and are mostly in portable applications. COMBINED DRILL & COUNTERSINKS • 798 - Plain style drill Combined drill and countersinks (Champion #798, & countersink 796) are designed to produce accurate conical holes HSS / 60º angle in components which require machining between • 796 - Bell style drill centers. & countersink HSS / 60º & 90º angles

HOW TO CHOOSE THE RIGHT SIZE COUNTERSINK (DIAMETER) A simple rule of thumb is to choose a countersink which is larger than the bolt size of hole. Countersink diameter = 1.5 x Bolt Size (hole) diameter. Example: For a 1/4-20 bolt, multiply the diameter (.250) x 1.5 = .375. This equates to a 3/8” countersink. HOW TO CALCULATE COUNTERSINK SPEEDS Countersinking is usually performed at 1/3 the RPM of drilling. First calculate drilling speed by using the formula below. Then simply divide by 3. Formula: SFM (surface feet/minute) x 3.82 / Cutter Diameter (decimal equivalent) / 3 Material Surface Feet / Minute (SFM) Sample Calculations for 1/4” Countersink Speed (RPM) Aluminum 200 - 250 (225 (SFM) x 3.82 / .2500) /3 = 1,146 RPM Mild Steel 100 - 110 (115 (SFM) x 3.82 / .2500) /3 = 586 RPM Stainless Steel 30 - 100 (65 (SFM) x 3.82 / .2500) /3 = 381 RPM * We recommend BruteLube to enhance performance and extend tool life for all cutting tools. For more information please contact our Customer Service Department at 516-536-8200 or visit our website at www.championcuttingtool.com