Step Tip Drill Bit Sets

Step Tip Drill Bit Selection — Quick Reference

Step tip drill bits (step drills / Unibit-style / stepped drills) = MULTIPLE DIAMETERS in ONE BIT — drill at smaller diameter, push deeper to increase hole size. Sheet metal + panel + multiple-size workflow.

Critical: Step drills for SHEET MATERIAL ONLY — not thick steel. Use CUTTING FLUID. Stops at required diameter — don't push past target size. Brand: Alpha, Sutton Tools. Companion: step drill bits, drilling, panel drill bits.

Step Tip Drill Bit Sets for Australian Sheet Metal and Panel Work

Step tip drill bits — also called step drills, Unibit-style drills, or stepped drills — are single-bit tools that drill multiple hole sizes by stepping through progressively larger diameters. Each step has a flat at the cutting edge that produces a clean entry hole with minimal burr, making them the right tool for thin sheet metal, panel work, and electrical enclosure drilling where standard twist drills tear and grab. AIMS Industrial supplies step tip drill bit sets in the sizes Australian trade users actually need.

How step tip drills work

The bit has a series of progressively larger steps along its length — typically 5mm, 6mm, 8mm, 10mm, 12mm, and so on up to 32mm or 40mm. Drill into the workpiece until the desired step diameter is reached, then stop. The result is a clean hole at exactly that diameter, with minimal burr at entry and exit. The same bit drills multiple hole sizes without tool changes, making it dramatically faster than swapping individual twist drills for varied-size sheet metal work.

Where step drills earn their place

• Electrical enclosure drilling — making clean holes for cable glands, switches, and panel hardware
• Automotive panel work — drilling clean holes through body panels, dashboards, and trim
• HVAC ducting — making holes for fastener access and instrument mounts
• Sheet metal fabrication — drilling varied-size holes without bit changes
• Service van modifications — installing accessories and storage with multiple hole sizes

Sizing — common step ranges

• 4-12mm step drills — small-hole work in thin sheet
• 4-22mm step drills — the everyday workshop range covering most sheet metal work
• 6-32mm step drills — larger-hole work and conduit penetrations
• 9-39mm step drills — heavy-duty step drills for larger panel work

Common step intervals are 1mm or 2mm — finer step intervals give more size choices but cost more. For most workshops, 2mm steps cover the work; production users may benefit from finer 1mm steps.

HSS versus titanium-coated versus carbide

• HSS step drills — the everyday choice for mild steel sheet, aluminium, and plastic
• Titanium-nitride (TiN) coated HSS — extended life in harder sheet materials
• Cobalt HSS (HSS-E) — for stainless steel and harder sheet metals
• Carbide-tipped step drills — for the toughest sheet materials and longest service life

Drilling practice

Run step drills at moderate RPM (typically 600-1500 RPM depending on diameter and material). Apply firm steady pressure — the step pattern naturally limits feed depth, so excessive force just bogs the drill down. Use cutting fluid (Tap Magic or similar) for steel and stainless work; aluminium and plastic can run dry. Withdraw and clear chips between steps for deeper holes. For very thin sheet, support the work on a backing material to prevent breakthrough damage.

Brands stocked at AIMS

Sutton Tools, Bordo, and Champion cover the step drill range across HSS, coated, and cobalt grades. Sets are typically supplied in hard cases with 2-5 step drills covering the standard size ranges.

Companion ranges at AIMS

Step tip drill bits sit alongside our broader drill bit range — see multi-purpose drill bits, panel drill bit sets, reduced shank drill bits, and holemaking tools for the related products.

Need help speccing step drills for sheet metal, electrical, or panel work? contact our team — we'll match step range and material grade to your work.