Product Description.
3‑piece HSS‑Co spiral step drill bit set with black‑oxide finish. 1/4‑inch hex shank fits most power drills. Three size ranges: 3/16‑7/8", 1/8‑1/2", 1/4‑3/4". Laser‑engraved inch markings for quick size reading. Split‑point tip prevents bit wandering. Spiral flutes rapidly evacuate chips. Creates smooth low‑burr holes for sheet metal. Great for hole enlarging, deburring tasks. Wear‑resistant for DIY and light industrial applications.
Usage Instructions.
Insert the 1/4" hex shank fully into drill chuck and tighten securely.
Keep drill perpendicular (90°) to workpiece surface, avoid tilted operation.
Use low‑to‑medium speed when drilling metal materials.
Apply steady moderate pressure; do not force or jam the drill bit.
Drill step‑by‑step to reach target hole size; pause often for heat dissipation.
For enlarging or deburring existing holes, rotate bit gently inside holes.
Stop drilling if bit overheats. Clear metal chips from flutes after use.
Wear safety goggles. Not suitable for hard reinforced steel.
