Which hole diameters can you drill with this step drill bit?

It features 9 steps in 2 mm increments for diameters of 4, 6, 8, 10, 12, 14, 16, 18, and 20 mm.

What type of shank does this Milwaukee step drill bit have?

It has an 8 mm 3-flat secure-grip shank to prevent slippage inside the drill chuck.

Which materials is this step drill bit suitable for?

It is suitable for drilling sheet metal, pipes, non-ferrous metals, stainless steel, and plastics.

Do you need to centre-punch before drilling?

No, the precision tip starts fast and accurately without walking or pre-punching.

Are the hole size markings visible while drilling?

Yes, the laser-engraved reference marks allow clear identification of hole sizes during use.

MILWAUKEE 48899320 increment borer 4-20 mm (9 2-mm increments)

Name: MILWAUKEE 48899320 increment borer 4-20 mm (9 2-mm increments)
Brand: MILWAUKEE
SKU: 02883345
Price: 33.6 EUR
Availability: InStock

Supplier number: MILWAUKEE 48899320 | EAN 0045242344406

Recommended Retail Price €74.96

33.60 tax incl.

€27.77 excl. VAT (incl. all environmental contributions)

On stock - immediately available

Delivery by DHL

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How does it work?

Buy Milwaukee products with a total order value of at least €250 excl. VAT.
For a total order value of €250 excl. VAT up to but excluding €500 excl. VAT, you receive a FREE Milwaukee 12-piece Tri-Lobe screwdriver set (4932472003) worth €55.90.
For a total order value of €500 excl. VAT up to but excluding €750 excl. VAT, you receive a FREE Milwaukee M18 125 mm Random Orbital Sander cordless random orbital sander (4933464228) worth €168.90.
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This promotion cannot be combined with the ongoing Milwaukee Cashback Promotion on Milwaukee hand tools. An invoice for which you receive a free Buy More, Get More gift therefore cannot also be submitted for the Milwaukee hand tools cashback promotion.
The promotion is valid from 01.10.2026 to 31.10.2026.
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Accurate drilling with Milwaukee

Practical benefits

Fast start without walking: The centering tip prevents wandering on smooth metal surfaces, letting you drill immediately without prior center punching.
Clear laser-etched size marks: Visible diameter markings remain legible during use, allowing you to stop precisely at your chosen hole diameter.
Secure grip in chuck: The 3-flat shank eliminates slippage in the drill chuck, ensuring consistent power transfer and control throughout drilling.

In a nutshell

The right choise for

With the Milwaukee 48899320 step drill bit, you can drill and enlarge holes from 4 to 20 mm in 2 mm increments using a single tool. Thanks to the precision centering tip, you start drilling immediately in sheet metal, pipes, stainless steel, and plastics without walking or centre-punching. The 8 mm 3-flat shank ensures a firm grip in the chuck and prevents slipping under load. Clear laser-engraved size marks remain visible while drilling so you stop at the exact diameter every time. It is ideal for installing cable glands and working on thin-gauge metals without warping.

Product information FAQ

€33.60

In stock - tax incl.

Key features according to our expert

Smallest diameter: 4 mm
Largest diameter: 20 mm
Shank size: 8 mm

Product description

Step drills are ideal for drilling into the following materials: - Ferrous & non-ferrous sheets metals, profiles and pipes. - Copper, brass and aluminium. - Stainless steel. - Plastics. - Maximum material thickness 4 mm. - To ensure best lifetime we recommend the use of a coolant.
Trades: - Electrical: drilling of panels and cabinets for cable gland installation. - Plumbing / HVAC: access holes for pipework and installation. - Metal workers / fabrication: various sizes and hole enlargement. - Automotive: holes for cable installation (mobile telephones, antennas, re-directing electrical wiring). - Maintenance repair operations: various applications, sizes and hole enlargement.
Step Drill advantages over conventional drill bits: - One drill bit to drill multiple sizes - Do more carry less! - Best option for enlarging existing holes. - More durable than twist drill bits, thick core resists breakage. - More accurate and less walking, tip starts on contact. - Clean burr free holes, less reaming required. - Drills plastic without splitting or cracking.
MILWAUKEE Advantages
Spot drill - Drill - Deburr - All in one go
RAPID STRIKE TIP: Accurate start without walking and fast drilling without the need to pre-drill the material.
Special tip and step geometry for jam-free performance - less risk of drill snagging when used with high speed cordless tools and also prevents deformation of the drilled material.
Optimised 2 flute ground sharpened edge geometry for 2 x faster and smoother cutting.
Produced from custom engineered steel with black oxide coating for 4 x longer life.
Optimised for use with high speed cordless drills.
Laser engraved size markings for best long term visibility.
Each step is relief ground to drill and deburr automatically.
With 3 flat secure grip to prevent step drill from slipping in the chuck and ensure maximum transmission of torque.

All Features

Smallest diameter: 4 mm
Largest diameter: 20 mm
Shank size: 8 mm
Number of steps: 9
Overall length (mm): 65
Shaft diameter (mm): 8

Brand MILWAUKEE
02883345
EAN 0045242344406
Supplier number MILWAUKEE 48899320

Frequently asked questions about this product

Answered by specialists

Which hole diameters can you drill with this step drill bit?: It features 9 steps in 2 mm increments for diameters of 4, 6, 8, 10, 12, 14, 16, 18, and 20 mm.
What type of shank does this Milwaukee step drill bit have?: It has an 8 mm 3-flat secure-grip shank to prevent slippage inside the drill chuck.
Which materials is this step drill bit suitable for?: It is suitable for drilling sheet metal, pipes, non-ferrous metals, stainless steel, and plastics.
Do you need to centre-punch before drilling?: No, the precision tip starts fast and accurately without walking or pre-punching.
Are the hole size markings visible while drilling?: Yes, the laser-engraved reference marks allow clear identification of hole sizes during use.