4-39mm Step Drill HSS-Co5 Spiral Flute 2 Cutting Edges 118° Point 90° Step Angle - Ruko GmbH

Achieve precise, time‑saving hole production with a single tool: HSS‑Co5 construction combined with a spiral‑fluted geometry and a 118° split point delivers durable performance and low burr formation across the 4–39 mm range; order directly via Metav Werkzeuge or consult their specialists for selection advice.

RUKO step drill bit — spiral‑fluted HSS‑Co5, 4–39 mm, 12 steps

RUKO step drill bit designed for efficient enlargement and deburring of holes in workshop and industrial settings, offering a broad diameter range with spiral flutes for continuous chip removal

• HSS‑Co5 cobalt for superior wear resistance
• Spiral‑fluted geometry for fast chip removal
• 12 steps covering 4–39 mm diameter range
• 118° split point for precise, burr‑reduced starts

Faster production with fewer tool changes

The multi‑step geometry reduces setup time by replacing multiple twist drills with one step drill that covers a wide diameter span. The 12 steps from 4–39 mm allow sequential hole enlargement without reclamping, which shortens cycle times and minimises machine downtime. For production workshops this means fewer tool changes, reduced inventory complexity and a smoother workflow, while the spiral flute improves chip evacuation compared with straight‑fluted variants.

Built for durability and clean hole starts

Constructed from HSS‑Co5, the tool provides higher hot‑hardness and wear resistance than standard high‑speed steels, so cutting edges retain form during prolonged use. The 118° split point with cross grind reduces walking at drill start and produces cleaner entries with less burr formation. These characteristics increase first‑pass quality and reduce rework, translating into measurable gains in throughput and consistency.

Secure gripping and efficient chip control

The shank with 3 flats ensures secure clamping and prevents slippage in chucks and drill holders, while the spiral‑fluted profile channels chips away from the cutting zone to reduce clogging. Improved chip evacuation lowers heat build‑up at the cutting edge, extending tool life and maintaining hole quality over longer runs. The two cutting edges maintain stable cutting forces, which helps preserve machine spindle bearings and fixture integrity.

Practical workshop guidance and compatibility

The tool is adaptable to common drilling equipment thanks to the standard shank geometry with three flats; it fits conventional chucks and many quick‑change holders. Selection of cutting speeds and feeds should follow material‑appropriate guidelines: the HSS‑Co5 core performs well across a range of metals, and conservative parameter adjustment at first use helps identify the optimal setting for specific alloys. For buyers seeking a balance of performance and reliability, the combination of spiral flutes and cobalt alloying offers a robust solution for mixed‑material workshops.

For tailored advice on the RUKO step drill and to place an order through Metav Werkzeuge in Emmerich, call +49 2822 7131930 or email info@metav-werkzeuge.com

Technical data

• Article number: 4000601724NW
• Label: Stufenbohrer Bohrber.4-39mm HSS-Co5 Spiralnut Z.2 Stufen 12 RUKO
• Manufacturer: Ruko GmbH
• Packaging unit: 1
• UID: 4000601724NW

Facts

• Diameter range: 4–39 mm
• Steps: 12
• Point angle: 118°
• Step angle: 90°
• Cutting edges: 2
• Shank: with 3 flats

Special features

• Material: HSS‑Co5
• Nut: spiral‑fluted
• Cross grind (split point)
• 2 cutting edges
• Stages: 12

FAQ

What diameter range does this step drill cover?
The RUKO step drill covers a continuous range between 4 and 39 mm across its 12 steps, enabling sequential hole enlargement without changing tools.

How does the HSS‑Co5 material benefit performance?
HSS‑Co5 provides improved hot‑hardness and wear resistance compared with standard high‑speed steel, so the RUKO step drill maintains cutting edge integrity under higher temperatures and longer runs.

Does the tool require special clamping?
No special holder is required; the shank with three flats allows secure clamping in standard chucks and many quick‑change systems, reducing the risk of slippage.

What advantage does the spiral flute bring?
The spiral‑fluted design promotes continuous chip evacuation away from the cutting zone, reducing clogging, heat build‑up and the likelihood of rework.

Is the split point useful for hole quality?
Yes. The 118° split point with cross grind reduces walking at the hole start and helps produce cleaner entries with less burr, improving first‑pass quality.

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