Step Drill Bits vs Spiral Flute for Metal
By Drill Hog® | Published: 2026-10-19
Category: Comparisons
Compare step drill bits and spiral flute step bits for metal drilling. Learn the trade-offs in chip removal, precision, and material compatibility.
Quick answer
Choose a standard step drill bit for general metal drilling where fast hole stepping is needed, or a spiral flute step bit like the Drill Hog® HELIX Cobalt M42 for cleaner holes and better chip evacuation in deeper or continuous cuts.
Chip removal and hole quality
Standard step drill bits push chips upward as you drill, which can clog the flutes in thicker metal or when drilling multiple holes in quick succession. Spiral flute step bits, such as the Drill Hog® HELIX Cobalt M42, use a twisted flute design that actively lifts chips away from the cutting edge, reducing heat buildup and producing a cleaner hole edge. This makes spiral flutes preferable for deep cuts or when hole finish matters.
Material compatibility and durability
Both types work on mild steel, aluminum, and stainless steel, but cobalt M42 alloy offers extra heat resistance and edge retention. The HELIX Cobalt M42 step bit includes sizes from 3/16" to 1/2" (6 steps) and 1/8" to 1/2" (13 steps), giving you flexibility for thin sheet metal or thicker plate. Standard step bits often lack this range or skip intermediate sizes.
Trade-offs at a glance
- Standard step drill bits: Best for quick, one-pass holes in thin sheet metal (up to 1/8") where chip evacuation is less critical. Lower cost per bit, but flutes can clog in thicker material.
- Spiral flute step bits (e.g., HELIX Cobalt M42): Better for deeper holes (1/4" to 3/4" material) and when hole finish matters. The spiral flute clears chips continuously, reducing heat and extending bit life. Higher initial cost but fewer replacements. If you drill multiple holes in thick metal, the spiral flute pays off in time saved and cleaner results.
- Cobalt M42 alloy: Both standard and spiral flute bits can use cobalt M42, but it is more common in premium spiral flute designs. M42 resists heat and wear better than HSS, especially in stainless steel. Check the bit material—cobalt M42 justifies a higher price if you work with tough alloys regularly.
Product facts
- Drill Hog® HELIX Cobalt M42 Spiral Flute Step Bit: Drill Hog® HELIX Cobalt M42 Spiral Flute Step Bit set includes 3 bits: 3/16" to 1/2" (6 steps), 1/8" to 1/2" (13 steps), and 1/4" to 3/4" (9 steps). You get a broad range of hole sizes in one set, reducing bit changes for common metal drilling tasks.
Drill Hog® HELIX Cobalt M42 Spiral Flute Step Bit
Which one fits your job?
Best for
- Thin sheet metal and quick hole stepping where speed matters more than finish
- Budget-conscious buyers who need a single bit for occasional metal drilling
Not ideal for
- Deep or continuous cuts in thick metal where chip clogging slows progress
- Projects requiring precise hole finish or minimal burr formation
