Chatterless Countersinks™

6-Flute Design Eliminates Harmonics for Smooth Countersinking

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Jump to: 6-Flute HSS 6-Flute Carbide Double-Ended Threaded Shank Heavy Duty Econo-Sinks Single Flute Stop-Countersink Stop Units Adjustable

The Chatter-Free Difference

Traditional single-flute countersinks create harmonics that cause chatter marks. Our 6-flute design eliminates this problem.

Severance Chatterless Countersinks feature a patented 6-flute design with unequal spacing that breaks up the harmonic patterns responsible for chatter. The result is smooth, burr-free countersinks with excellent surface finish - even in interrupted cuts and difficult materials.

Traditional Countersinks
  • Single flute creates harmonics
  • Chatter marks on surface
  • Rough finish, burrs
  • Tool grabbing in soft materials
Chatterless Design
  • 6 flutes break up harmonics
  • Smooth, mark-free finish
  • Clean, burr-free edges
  • Controlled cutting action
Severance Chatterless Countersinks - 6-Flute Design
Available Angles

Countersinks available in standard included angles:

  • 60° (30° per side)
  • 82° (41° per side) - Standard
  • 90° (45° per side)
  • 100° (50° per side)
  • 110° (55° per side)
  • 120° (60° per side)
Pro Tip

82° included angle is the standard for flat-head machine screws in the USA. Use 90° for metric applications.

6-Flute HSS Chatterless Countersinks

6-Flute HSS Chatterless Countersink diagram

Premium M2 high-speed steel countersinks with the original 6-flute chatterless design. Standard 82° included angle.

Available in all 6 standard included angles. Specify angle when ordering.

Body Dia. Shank Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1/8"1-5/8"CK-1/8023700239002410024300245002470
3/16"3/16"1-1/2"CK-3/16023710239102411024310245102471
1/4"3/16"1-1/2"CK-1/4023720239202412024320245202472
5/16"1/4"1-3/4"CK-5/16023730239302413024330245302473
3/8"1/4"1-3/4"CK-3/8023740239402414024340245402474
1/2"3/8"2-1/8"CK-1/2023750239502415024350245502475
1/2"1/4"2-1/8"CK-1/2-1/4023760239602416024360245602476
5/8"3/8"2-3/8"CK-5/8023770239702417024370245702477
5/8"1/4"2-3/8"CK-5/8-1/4023780239802418024380245802478
3/4"1/2"2-11/16"CK-3/4023790239902419024390245902479
7/8"1/2"2-13/16"CK-7/8023800240002420024400246002480
1"1/2"2-13/16"CK-1023810240102421024410246102481
1-1/4"3/4"3-3/8"CK-1-1/4023820240202422024420246202482
1-1/2"3/4"3-1/2"CK-1-1/2023830240302423024430246302483
1-3/4"1"4-1/4"CK-1-3/4023840240402424024440246402484
2"1"4-3/8"CK-2023850240502425024450246502485
2-1/2"1"4-3/4"CK-2-1/2023860240602426024460246602486
3"1"5"CK-3023870240702427024470246702487

6-Flute Carbide Chatterless Countersinks

6-Flute Carbide Chatterless Countersink

Solid carbide construction for maximum tool life in abrasive materials and high-volume production. 10-20x longer life than HSS in most applications.

Available in all 6 standard included angles. Specify angle when ordering.

Body Dia. Shank Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1/8"1-1/2"CK-1/8-W025200254002560025800260002620
3/16"3/16"1-1/2"CK-3/16-W025210254102561025810260102621
1/4"3/16"1-1/2"CK-1/4-W025220254202562025820260202622
5/16"1/4"2-1/4"CK-5/16-W025230254302563025830260302623
3/8"1/4"2-1/4"CK-3/8-W025240254402564025840260402624
1/2"3/8"2-1/2"CK-1/2-W025250254502565025850260502625
1/2"1/4"2-1/4"CK-1/2-W-1/4025260254602566025860260602626
5/8"3/8"2-5/8"CK-5/8-W025270254702567025870260702627
5/8"1/4"2-3/8"CK-5/8-W-1/4025280254802568025880260802628
3/4"1/2"2-3/4"CK-3/4-W025290254902569025890260902629
7/8"1/2"2-7/8"CK-7/8-W025300255002570025900261002630
1"1/2"3"CK-1-W025310255102571025910261102631

Double-Ended Countersinks

Double-Ended Countersink diagram

Two countersinks in one tool - when one end wears, flip it around for a fresh cutting edge. Economical for high-volume shops.

HSS Double-Ended

Body Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1-1/2"CK-1/8-DE026700268502700027150273002745
3/16"1-7/8"CK-3/16-DE026710268602701027160273102746
1/4"2"CK-1/4-DE026720268702702027170273202747
5/16"2-1/8"CK-5/16-DE026730268802703027180273302748
3/8"2-1/2"CK-3/8-DE026740268902704027190273402749
1/2"3"CK-1/2-DE026750269002705027200273502750
5/8"3-1/4"CK-5/8-DE026760269102706027210273602751
3/4"3-1/2"CK-3/4-DE026770269202707027220273702752

Carbide Double-Ended

Body Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1-1/2"CK-1/8-W-DE028200283502850028650288002895
3/16"2"CK-3/16-W-DE028210283602851028660288102896
1/4"2"CK-1/4-W-DE028220283702852028670288202897
5/16"2-1/8"CK-5/16-W-DE028230283802853028680288302898
3/8"2-1/2"CK-3/8-W-DE028240283902854028690288402899
1/2"3"CK-1/2-W-DE028250284002855028700288502900
5/8"3-1/4"CK-5/8-W-DE028260284102856028710288602901
3/4"3-1/2"CK-3/4-W-DE028270284202857028720288702902

Threaded Shank Countersinks

Threaded Shank Countersink diagram

Threaded shank design for use with countersink holders and quick-change systems. Secure clamping prevents slippage.

Body Dia. Thread OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
3/4"3/8"-241-1/2"CK-3/4-T032700328003290033000331003320
7/8"3/8"-241-1/2"CK-7/8-T032710328103291033010331103321
1"1/2"-201-1/2"CK-1-T032720328203292033020331203322
1-1/4"5/8"-181-3/4"CK-1-1/4-T032730328303293033030331303323
1-1/2"3/4"-161-7/8"CK-1-1/2-T032740328403294033040331403324
1-3/4"3/4"-162-1/8"CK-1-3/4-T032750328503295033050331503325
2"3/4"-162-1/4"CK-2-T032760328603296033060331603326
2-1/2"1"-143"CK-2-1/2-T032770328703297033070331703327
3"1-1/4"-123-1/4"CK-3-T032780328803298033080331803328

Heavy Duty Countersinks

Heavy Duty Countersink diagram

Extra-robust construction for demanding applications. Larger shank diameters and increased flute depth for aggressive material removal.

Available in N (normal) and F (fine) tooth configurations. Available in 60°, 82°, and 90° included angles. Designed for use with Glenzer sleeve adapters.

Body Dia. Shank Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP
3/8"13/32"2-13/16"HD-3/8-N039200394003960
3/8"13/32"2-13/16"HD-3/8-F039210394103961
1/2"13/32"3-1/16"HD-1/2-N039220394203962
1/2"13/32"3-1/16"HD-1/2-F039230394303963
3/4"3/4"3-7/8"HD-3/4-N039240394403964
3/4"3/4"3-7/8"HD-3/4-F039250394503965
1"3/4"4-5/16"HD-1-N039260394603966
1"3/4"4-5/16"HD-1-F039270394703967
1-1/4"1"5"HD-1-1/4-N039280394803968
1-1/4"1"5"HD-1-1/4-F039290394903969
1-1/2"1"5-1/4"HD-1-1/2-N039300395003970
1-1/2"1"5-1/4"HD-1-1/2-F039310395103971
2"1"5-3/4"HD-2-N039320395203972
2"1"5-3/4"HD-2-F039330395303973

Glenzer Sleeve Adapters

Sleeve adapters for use with Heavy Duty Countersinks. Allow mounting of HD-series countersinks in standard drill chucks and tool holders.

Description EDP
Glenzer Sleeve Adapter - Small36210
Glenzer Sleeve Adapter - Medium36211
Glenzer Sleeve Adapter - Large36212

4-Flute Chatter-Free® Econo-Sinks®

An economical alternative to our 6-flute countersinks, the 4-Flute Econo-Sinks provide excellent chatter-free performance at a lower cost. Ideal for general-purpose countersinking applications.

4-Flute Econo-Sink
Features:
  • 4-flute chatter-free design
  • Economical pricing for high-volume applications
  • Available in HSS and Carbide
  • All 6 standard included angles available
  • Sizes from 1/8" to 3" diameter

HSS Econo-Sinks

Available in all 6 standard included angles. Specify angle when ordering.

Body Dia. Shank Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1/8"1-5/8"ES-1/8009700099101012010330105401075
3/16"3/16"1-1/2"ES-3/16009710099201013010340105501076
1/4"3/16"1-1/2"ES-1/4009720099301014010350105601077
5/16"1/4"1-3/4"ES-5/16009730099401015010360105701078
3/8"1/4"1-3/4"ES-3/8009740099501016010370105801079
1/2"3/8"2-1/8"ES-1/2009760099701018010390106001081
1/2"1/4"2-1/8"ES-1/2-1/4009770099801019010400106101082
5/8"3/8"2-3/8"ES-5/8009780099901020010410106201083
5/8"1/4"2-3/8"ES-5/8-1/4009790100001021010420106301084
3/4"1/2"2-11/16"ES-3/4009800100101022010430106401085
7/8"1/2"2-13/16"ES-7/8009820100301024010450106601087
1"1/2"2-13/16"ES-1009830100401025010460106701088
1-1/4"3/4"3-3/8"ES-1-1/4009840100501026010470106801089
1-1/2"3/4"3-1/2"ES-1-1/2009850100601027010480106901090
1-3/4"1"4-1/4"ES-1-3/4009870100801029010500107101092
2"1"4-3/8"ES-2009880100901030010510107201093
2-1/2"1"4-3/4"ES-2-1/2009890101001031010520107301094
3"1"5"ES-3009900101101032010530107401095

Carbide Econo-Sinks

Body Dia. Shank Dia. OAL Tool Name 60° EDP 82° EDP 90° EDP 100° EDP 110° EDP 120° EDP
1/8"1/8"1-1/2"ES-1/8-W011200113501150011650118001195
1/4"3/16"1-1/2"ES-1/4-W011210113601151011660118101196
3/8"1/4"2-1/4"ES-3/8-W011220113701152011670118201197
1/2"3/8"2-1/4"ES-1/2-W011250114001155011700118501200
5/8"3/8"2-5/8"ES-5/8-W011260114101156011710118601201
3/4"1/2"2-3/4"ES-3/4-W011270114201157011720118701202
1"1/2"3"ES-1-W011280114301158011730118801203

Single Flute Countersinks

Single Flute Countersink diagram

Economical option for light-duty applications. Single flute design with pilot for accurate hole centering.

Body Dia. Shank Dia. OAL Tool Name 82° HSS EDP
1/4"3/16"1-1/2"1/4-SF00290
3/8"1/4"1-3/4"3/8-SF00292
1/2"3/8"2-1/8"1/2-SF00293
5/8"3/8"2-3/8"5/8-SF00295
3/4"1/2"2-11/16"3/4-SF00297
1"1/2"2-13/16"1-SF00299

Chatter-Free® Stop-Countersink Cutters

Stop-Countersink Cutters are designed for use with Severance Precision Stop Countersink Units (SC-14 through SC-57). Available in 5 included angles with multiple pilot diameter options per body size. All cutters have 1/4"-28 threads.

Stop-Countersink Cutter
Features:
  • Threaded shank (1/4"-28) for use with SC- stop units
  • Chatter-free cutting action
  • Multiple pilot diameters per body size
  • 5 included angles: 78°, 82°, 90°, 100°, 120°
  • 4 body sizes: 3/8" (SC-6), 7/16" (SC-7), 1/2" (SC-8), 5/8" (SC-10)

SC-6 Cutters (3/8" Body)

Pilot Dia. 78° EDP 82° EDP 90° EDP 100° EDP 120° EDP
3/32" (.0938)1534015485156291577415919
#40 (.0980)1534115486156301577515920
1/8" (.1250)1534215487156311577615921
#30 (.1285)1534315488156321577715922
5/32" (.1562)1534515489156341577915924
#21 (.1590)1534615490156351578015925
3/16" (.1875)1534715491156361578115926
#10 (.1935)1534815492156371578215927

SC-7 Cutters (7/16" Body)

Pilot Dia. 78° EDP 82° EDP 90° EDP 100° EDP 120° EDP
3/32" (.0938)1535015494156391578415929
#40 (.0980)1535115495156401578515930
1/8" (.1250)1535215496156411578615931
#30 (.1285)1535315497156421578715932
5/32" (.1562)1535515499156441578915934
#21 (.1590)1535615500156451579015935
3/16" (.1875)1535715501156461579115936
#10 (.1935)1535815502156471579215937

SC-8 Cutters (1/2" Body)

Pilot Dia. 78° EDP 82° EDP 90° EDP 100° EDP 120° EDP
3/32" (.0938)1536015504156491579415939
#40 (.0980)1536115505156501579515940
1/8" (.1250)1536215506156511579615941
#30 (.1285)1536315507156521579715942
5/32" (.1562)1536415508156531579815943
#21 (.1590)1536615510156551580015945
3/16" (.1875)1536715511156561580115946
#10 (.1935)1536815512156571580215947
7/32" (.2187)1536915513156581580315948
1/4" (.2500)1537015514156591580415949

SC-10 Cutters (5/8" Body)

Pilot Dia. 78° EDP 82° EDP 90° EDP 100° EDP 120° EDP
1/8" (.1250)1537215516156611580615951
#30 (.1285)1537315517156621580715952
5/32" (.1562)1537415518156631580815953
#21 (.1590)1537515519156641580915954
3/16" (.1875)1537615520156651581015955

Precision Stop Countersink Units

Severance Precision Stop Countersink Units convert your drill press into a precision countersinking unit, giving you identical countersinks on parts of various thicknesses. Designed for hand power-tool and drill-press use. Units accept threaded SC- series cutters (sold separately).

Precision Stop Countersink Unit
Features:
  • Precision depth control for consistent countersinks
  • Spring-loaded for consistent pressure
  • Accepts threaded SC- series stop-countersink cutters
  • Available in light duty through super duty configurations
  • "R" suffix models feature reverse rotation capability
  • "P" suffix models feature positive stop
Unit Name Type Max Cutter Shank Dia. Outside Dia. Internal Thread Stroke EDP
SC-14Light Duty7/16"1/4"7/8"1/4"-28.180"21220
SC-24Standard Duty3/4"1/4"1-1/16"1/4"-28.180"21221
SC-24RStandard Duty (Reverse)3/4"1/4"1-1/16"1/4"-28.180"21227
SC-25PStandard Duty (Positive)3/4"1/4"1-1/16"1/4"-28.180"21322
SC-25PRStandard Duty (Pos/Rev)3/4"1/4"1-1/16"1/4"-28.180"21323
SC-35PHeavy Duty (Positive)3/4"3/8"1-1/16"3/8"-24.180"21324
SC-35PRHeavy Duty (Pos/Rev)3/4"3/8"1-1/16"3/8"-24.180"21325
SC-36Heavy Duty3/4"3/8"1-1/16"3/8"-24.180"21222
SC-36RHeavy Duty (Reverse)3/4"3/8"1-1/16"3/8"-24.180"21228
SC-47Long Stroke Super Duty1-1/4"1/2"1-3/4"7/16"-20.280"21223
SC-57Long Stroke Heavy Duty1-1/4"3/8"1-3/4"3/8"-24.280"21224

Non-Marking Nylon Foot Accessories

For Unit Max Cutting Dia. With Foot Part Number EDP
SC-147/16"SC-14-1121245
SC-245/8"SC-24-1121264
SC-365/8"SC-36-1121264
SC-471-1/4"SC-47-1121302
SC-571-1/4"SC-57-1121302

Adjustable Countersinks

Combination drill and countersink tools with specific built-in drill sizes for aircraft fastener applications. Each tool is sized for a specific drill diameter. Available in 82° and 90° included angles.

Aircraft Style Stop Countersink
Features:
  • Specific drill size built into each tool
  • 5 body sizes: 6-AC (3/8"), 8-AC (1/2"), 10-AC (5/8"), 14-AC (7/8"), 18-AC (1-1/8")
  • Available in 82° and 90° included angles
  • Designed for aircraft and aerospace fastener applications
Body Dia. Drill Size OAL Tool Name 82° EDP 90° EDP
6-AC Series (3/8" Body)
3/8"1/8" (.1250)1"6-AC-20357203622
3/8"#29 (.1360)1"6-AC-290357303623
3/8"#28 (.1405)1"6-AC-280357403624
3/8"#25 (.1495)1"6-AC-250357503625
3/8"#21 (.1590)1"6-AC-210357603626
3/8"#19 (.1660)1"6-AC-190357703627
8-AC Series (1/2" Body)
1/2"3/16" (.1875)1-1/8"8-AC-3/160357803628
1/2"#16 (.1770)1-1/8"8-AC-160357903629
1/2"#14 (.1820)1-1/8"8-AC-140358003630
1/2"7/32" (.2188)1-1/8"8-AC-7/320358103631
1/2"#10 (.1935)1-1/8"8-AC-100358203632
1/2"#7 (.2010)1-1/8"8-AC-70358303633
10-AC Series (5/8" Body)
5/8"7/32" (.2188)1-1/8"10-AC-7/320358403634
5/8"1/4" (.2500)1-1/8"10-AC-40358503635
5/8"#3 (.2130)1-1/8"10-AC-30358603636
5/8"#2 (.2210)1-1/8"10-AC-20358703637
5/8"9/32" (.2813)1-1/8"10-AC-9/320358803638
5/8"5/16" (.3125)1-1/8"10-AC-5/160358903639
5/8"D (.2460)1-1/8"10-AC-D0359003640
5/8"I (.2720)1-1/8"10-AC-I0359103641
5/8"F (.2570)1-1/8"10-AC-F0360303604
14-AC Series (7/8" Body)
7/8"Q (.3320)1-1/2"14-AC-Q0359203642
7/8"R (.3390)1-1/2"14-AC-R0359303643
7/8"S (.3480)1-1/2"14-AC-S0359403644
7/8"3/8" (.3750)1-1/2"14-AC-3/80359503645
7/8"U (.3680)1-1/2"14-AC-U0359603646
7/8"25/64" (.3906)1-1/2"14-AC-25/640359703647
18-AC Series (1-1/8" Body)
1-1/8"27/64" (.4219)1-3/4"18-AC-27/640359803648
1-1/8"7/16" (.4375)1-3/4"18-AC-7/160359903649
1-1/8"29/64" (.4531)1-3/4"18-AC-29/640360003650
1-1/8"1/2" (.5000)1-3/4"18-AC-1/20360103651
1-1/8"31/64" (.4844)1-3/4"18-AC-31/640360203652

Technical Data & Speed/Feed Recommendations

Chatterless Countersinks perform best at moderate speeds with consistent feed rates. The 6-flute design allows for higher feed rates than conventional countersinks while maintaining a smooth finish.

HSS Countersinks
Material RPM (1/2" dia) Feed IPR
Aluminum 2000-3000 .003-.006"
Brass/Bronze 1500-2500 .002-.004"
Mild Steel 500-1000 .002-.003"
Stainless Steel 300-600 .001-.002"
Carbide Countersinks
Material RPM (1/2" dia) Feed IPR
Aluminum 4000-6000 .004-.008"
Brass/Bronze 3000-5000 .003-.005"
Mild Steel 1000-2000 .002-.004"
Stainless Steel 600-1200 .001-.003"
Why Chatterless?

Traditional 4-flute countersinks create harmonic vibrations that cause chatter marks on the countersink surface. The 6-flute Chatterless design interrupts these harmonics, producing smooth, professional finishes even at higher feed rates. This allows for faster cycle times without sacrificing quality.

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Need a Custom Countersink Solution?

We manufacture custom angles, sizes, and configurations. Contact our engineering team for a quote.

Contact Us 989-777-5500