4-12mm Step Drill HSS-Co5 Spiral Flute 2-Flute 118° Point, 90° Step Angle - Ruko GmbH

Take advantage of the combination of robust HSS-Co5 cutting performance, spiral-fluted chip evacuation, and a 3-flat shank for secure clamping to maintain consistent hole quality in production or repair work. Order directly via Metav Werkzeuge or consult our specialists for compatibility and stock information.

RUKO Step Drill 4–12 mm — HSS‑Co5, spiral‑fluted, 2‑cut

A RUKO Step Drill 4–12 mm designed for precise stepped holes in thin metals and technical plastics, with spiral flutes and a 3‑flat shank for reliable clamping.

• HSS‑Co5 for enhanced wear resistance
• Spiral‑fluted for effective chip removal
• 3‑flat shank for secure clamping
• 118° point angle for fast centring

Consistent cutting with high‑alloy steel for longer tool life

The HSS‑Co5 composition denotes high‑speed steel with added cobalt, which increases red‑hardness and wear resistance under elevated temperatures. This alloyed construction provides a stable cutting edge when machining thin stainless steel, mild steel or non‑ferrous metals. The tool’s two cutting edges and cross‑ground point reduce vibration at entry, producing cleaner first steps and minimising burr formation — a direct benefit where repeatable hole quality is required across batches.

Reliable chip control for uninterrupted processes

The spiral‑fluted geometry evacuates chips more effectively than straight‑fluted step drills, lowering the risk of clogging in the stepped profile and reducing heat build‑up. Improved chip flow leads to fewer interruptions and longer intervals between tool checks. This geometry, combined with the step angle of 90° and precisely ground steps, simplifies deburring and trimming operations, which supports faster cycle times in assembly or fabrication workflows.

Secure clamping and accurate centring for production use

A shank with three flats permits secure clamping in standard chucks and collets, preventing slippage during heavier feed rates. The 118° point angle encourages reliable centring without the need for a pilot drill in many applications, saving preparation time. With a nominal drilling range of 4–12 mm across the stepped profile, the design is well suited for progressive hole enlargement in sheet work and thin plate, reducing tool changes and setup complexity for repetitive tasks.

For precise step drilling choose the RUKO HSS‑Co5 step drill and contact Metav Werkzeuge for stock checks or technical advice direct from Emmerich: info@metav-werkzeuge.com, +49 2822 7131930

Technical Data

• Article number: 4000601721NW
• Label: Stufenbohrer Bohrber.4-12mm HSS-Co5 Spiralnut Z.2 Stufen 9 RUKO
• Manufacturer: Ruko GmbH

Facts

• Drilling range: 4–12 mm
• Steps: 9
• Point angle: 118°
• Step angle: 90°
• Cutting edges: 2

Special features

• Material: HSS‑Co5
• Flute: spiral‑fluted
• Tip: cross‑ground point
• Shank: with 3 flats
• Geometry: step drill with 90° step angle

FAQ

What materials can be machined with this step drill?
The RUKO step drill is made from HSS‑Co5 and is suitable for steels and many non‑ferrous metals; its alloyed composition improves performance when cutting mild steel and some stainless grades.

Is a pilot hole required before using the step drill?
Often no pilot is necessary thanks to the 118° point angle and cross‑ground tip, but a pilot hole can be used in very thin or highly stressed sheets to ensure exact positioning.

How does the spiral flute affect drilling performance?
Spiral flutes promote continuous chip evacuation and reduce clogging in the stepped profile, which preserves cutting edges and maintains consistent hole quality.

Can the tool be held in standard chucks?
Yes; the shank with three flats provides secure clamping in common chucks and collet systems to prevent slippage under load.

What size range does the tool cover and how precise are the steps?
The tool covers stepped diameters from 4 to 12 mm across nine steps, each step ground for repeatable diameters and reduced burr formation.

Manufacturer/Responsible: Ruko GmbH Präzisionswerkzeuge, Robert‑Bosch‑Strasse 7, 71088 Holzgerlingen