Drill bit set Bosch step HSS 3 pcs 4–30 mm; sizes 4–12, 4–20, 6–30 mm

Bosch step drill bit set of 3 HSS pieces covers a wide drilling range up to 30 mm and is designed for progressive hole enlargement in sheet metal, thin materials and plastics. The set contains three step bits with ranges 4–12 mm, 4–20 mm and 6–30 mm, enabling versatile use without frequent tool changes. These HSS step bits are suitable for use with electric drills and drill presses and provide efficient cutting and deburring in one operation.

Advantages

The compact 3‑piece set reduces the need to change bits when enlarging holes and saves storage space. High-speed steel construction offers good wear resistance and stable cutting performance on thin metal and plastic. The stepped design enables controlled incremental drilling and integrated deburring, producing cleaner hole edges and reducing finishing work. Compatibility with standard drill chucks makes the bits easy to fit on most drilling machines.

Suitable for

Key specifications

How to use

Select the step bit with the appropriate range for the target hole size, mount it securely in the drill chuck and set the drill to a moderate speed suitable for the material being drilled. Start drilling with light pressure to locate the hole, then increase steady pressure while allowing the bit to cut through progressively larger steps. Withdraw the bit intermittently if necessary to clear chips and reduce heat. After drilling, use the larger steps to deburr the hole edge if required.

Recommendations

Use cutting lubricant when working with thicker or harder sheet metal to prolong bit life and improve hole quality. Secure thin workpieces with clamps or a vice to prevent vibration and ensure precise hole placement. Replace the bit if wear causes reduced cutting efficiency or excessive burr formation.