Aircraft Tool Supply Countersink Kit W/Pilot Cutter

Q: what does the number stand-for for the countersink cutter? sometime is #40, #21, sometime is 1/4", I need 1/8" or 5/32", do you have?

The number is standard drill size. #40 being slightly larger than 3/32" and #30 slightly larger than 1/8". A quick google will give you a conversion chart. They do also sell them in standard sizes like 3/32 or 1/4, but you may have to contact ATS directly.

Q: Although this seems to be used for rivets on aircraft, can it also be used on solid aluminum and steel millwork projects for flat head machine screws?

Hello, Unfortunately this item will not work for the purpose you are proposing. These pilot cutters are 100 degree 3 flute cutting edge and I believe if you are using AN screws they will require a 82 degree cutter which we do not sell.

Q: What is the Thread size of the cutter's shank? (IE 1/4-28 ?)

It looks like 1/4" 28. I don't have any fine thread nuts around. It catches the first thread on 1/4 20 but won't go any further.

Q: Is it 60 degrees or, like most countersinks, 80 degrees? They don't say in the description.

100 degree counter sinks -- for standard aviation rivets AD426-xxxx

Product ID: 6310901

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Details

Material
metal
Finish Type
Uncoated
Shank Type
Straight
Brand
Aircraft Tool
Tool Flute Type
Spiral

🎯Pilot cutter ensures pinpoint accuracy

⚙️2-flute spiral for smooth chip removal

🛠️Stainless steel for corrosion resistance

Description

🎯 Drill with precision, finish with pride!

BUILT TO LAST - Durable stainless steel construction resists corrosion and wear
METAL MASTERY - Optimized for countersinking metal surfaces—your go-to for versatile projects
PINPOINT ACCURACY - Included pilot cutter guarantees exact starting points for flawless drilling
PRECISION PERFECTED - Professional-grade countersink delivers clean, accurate holes every time
EFFORTLESS EFFICIENCY - 2-flute spiral design minimizes binding and speeds up chip clearance

The Aircraft Tool Supply Countersink Kit features a professional-grade, 2-flute spiral countersink bit made from corrosion-resistant stainless steel. It includes a pilot cutter for precise hole starting points, designed specifically for clean, accurate countersinking in metal surfaces. Durable and efficient, this tool is essential for any serious metalworking project.

Specifications

Material	metal
Finish Type	Uncoated
Shank Type	Straight
Brand	Aircraft Tool Supply
Tool Flute Type	Spiral
Point Style	Taper Point
Surface Recommendation	Metal
Number of Flutes	2
Unit Count	1.0 Count
Manufacturer	Aircraft Tool Supply
Part Number	133KIT
Item Weight	1 pounds
Package Dimensions	7.2 x 3.54 x 1.14 inches
Item model number	Aircraft Tool Supply [SOMETHING]
Is Discontinued By Manufacturer	No
Finish	Uncoated
Item Package Quantity	1
Batteries Included?	No
Batteries Required?	No

Have a Question? See What Others Asked

what does the number stand-for for the countersink cutter? sometime is #40, #21, sometime is 1/4", I need 1/8" or 5/32", do you have?

Although this seems to be used for rivets on aircraft, can it also be used on solid aluminum and steel millwork projects for flat head machine screws?

What is the Thread size of the cutter's shank? (IE 1/4-28 ?)

Is it 60 degrees or, like most countersinks, 80 degrees? They don't say in the description.