0.040"–0.125" Holley Carburetor Jet Drill Set – 50 Pc Factory Resharpened Carbide HS1

Holley Carburetor Jet Drill Set – 50 Piece .040"–.125"

This 50-piece factory resharpened solid carbide drill set provides a broad assortment of drill sizes from .0400" through .1250". It is especially useful for Holley carburetor jet sizing, checking, matching, tuning, and careful enlargement when a wide range of small carbide drill sizes is needed in one organized set.

This range may also be useful for larger automotive carburetor jet work, including Rochester, Carter, Quadrajet-style, AFB/AVS-style, and similar carburetor applications. Always verify the required jet diameter for your specific carburetor and tuning setup before drilling.

Each drill has a standard 1/8" (3.175 mm) shank and approximately 1.50" overall length. The set is supplied in a protective indexed storage case with a full size chart for easy reference.

Included Sizes – 50 Pieces Total

Includes 1 drill each of the following sizes:

• .0400" — #60
• .0413" — #59 / 1.05 mm
• .0420" — #58
• .0433" — #57 / 1.10 mm
• .0441" — 1.12 mm
• .0453" — 1.15 mm
• .0465" — #56
• .0472" — 1.20 mm
• .0492" — 1.25 mm
• .0512" — 1.30 mm
• .0520" — #55
• .0531" — 1.35 mm
• .0551" — 1.40 mm
• .0571" — 1.45 mm
• .0591" — 1.50 mm
• .0610" — 1.55 mm
• .0625" — 1/16"
• .0635" — #52
• .0650" — 1.65 mm
• .0669" — 1.70 mm
• .0689" — 1.75 mm
• .0700" — #50
• .0709" — 1.80 mm
• .0728" — #49 / 1.85 mm
• .0748" — 1.90 mm
• .0760" — #48
• .0787" — #47 / 2.00 mm
• .0807" — #46 / 2.05 mm
• .0820" — #45
• .0827" — 2.10 mm
• .0846" — 2.15 mm
• .0860" — #44
• .0866" — 2.20 mm
• .0906" — 2.30 mm
• .0925" — 2.35 mm
• .0938" — 3/32"
• .0945" — 2.40 mm
• .0960" — #41
• .0965" — 2.45 mm
• .0980" — #40
• .0995" — #39
• .1004" — 2.55 mm
• .1015" — #38
• .1024" — 2.60 mm
• .1043" — #37 / 2.65 mm
• .1083" — 2.75 mm
• .1102" — #35 / 2.80 mm
• .1161" — #32 / 2.95 mm
• .1181" — 3.00 mm
• .1250" — 1/8"

Specifications

• 50 drills total
• 50 different sizes
• 1 drill of each listed size
• Size range: .0400" through .1250"
• Factory resharpened solid carbide drills
• Standard 1/8" shank, also known as 3.175 mm
• Approximately 1.50" overall length
• Set ID: HS1
• Protective indexed storage case included
• Full size chart included for easy identification

Common Uses

• Holley carburetor jet sizing and tuning
• Checking and matching existing jet openings
• Careful enlargement of brass carburetor jets
• Rochester, Carter, Quadrajet-style, and AFB/AVS-style carburetor jet work when the required diameter falls within the included range
• Main jet sizing and modification
• Checking, matching, or stepping up drill sizes
• Precision small-hole drilling in brass and similar suitable materials

Factory Resharpened Solid Carbide Value

These are factory resharpened solid carbide drills. They are not new drills. Factory resharpening provides a practical lower-cost way to obtain a broad assortment of professional-style carbide drills for precision drilling work.

The full 1/8" shanks provide substantially greater rigidity than lightweight wire-style hobby drill assortments, and the indexed storage case keeps the full size range organized for quick reference.

Use note: Solid carbide drills are extremely hard and wear resistant, but they are also brittle. For best results, use a pin vise, drill press, milling machine, micro-drill fixture, CNC machine, or other controlled holder that keeps the drill straight and the work stable.

Avoid handheld electric drills, side pressure, bending, forcing the drill, or using the drill like a reamer.

Important Carburetor Jet Information

Carburetor jet numbers do not always correspond directly to the actual physical bore diameter, and numbering systems can vary by manufacturer and jet series. Verify the actual diameter required before modifying a jet.

Drilling a carburetor jet is a permanent modification. Increase the opening gradually and do not skip too far at once. Fuel flow may also be affected by the shape, length, entry, exit, and finish of the metering passage, not only by its diameter.

Frequently Asked Questions

Are these new drills?
No. These are factory resharpened solid carbide drills.

Is this set specifically for Holley carburetor jets?
The .040"–.125" size range is especially useful for many Holley carburetor jet applications. It may also be useful for Rochester, Carter, Quadrajet-style, AFB/AVS-style, and similar carburetors when the required jet diameter falls within the included range.

Is this the best set for small motorcycle, scooter, RC, or small-engine carburetors?
Not usually. For many smaller carburetor jet jobs, the 20 Pc Selected Sizes set, the 25 Pc #75–#51 set, or the D7 #80–#56 set may be a better starting point. This HS1 set is focused on a larger .040"–.125" range.

How many drills are included?
This set includes 50 drills total, with 1 drill of each listed size from .0400" through .1250".

Are these solid carbide or carbide tipped?
These are solid carbide drills, not carbide-tipped drills.

Can these be used by hand?
Yes, carefully in a pin vise or other controlled holder. Keep the drill straight, use light pressure, and avoid side loading.

👉 View Carbide Drill Bit Feed & Speed Starting Guide