EZARC 4–12mm M35 Cobalt Step Drill Bit / Unibit – 9 Steps, AlTiN Coated, Spiral Flute, 1/4" Hex Shank, For Metal, Stainless Steel & Aluminium

EZARC 4–12mm M35 Cobalt Step Drill Bit / Unibit – 9 Steps, AlTiN Coated, Spiral Flute, 1/4" Hex Shank, For Metal, Stainless Steel & Aluminium9 Steps. M35 Cobalt. AlTiN Coated. One Bit for Every Hole Size. Sheet metal, stainless steel, aluminium, brass, copper, cast iron the EZARC 412mm M35 Cobalt Step Drill Bit (also known as a unibit or cone drill bit) cuts clean, precise holes in a single pass without needing to swap bits. Nine steps from 4mm to 12mm in 1mm increments, M35 cobalt high speed steel for superior hardness and toughness, and an AlTiN coating rated at 89 HRC that withstands

9 Steps. M35 Cobalt. AlTiN Coated. One Bit for Every Hole Size.

Sheet metal, stainless steel, aluminium, brass, copper, cast iron — the EZARC 4–12mm M35 Cobalt Step Drill Bit (also known as a unibit or cone drill bit) cuts clean, precise holes in a single pass without needing to swap bits. Nine steps from 4mm to 12mm in 1mm increments, M35 cobalt high-speed steel for superior hardness and toughness, and an AlTiN coating rated at 89 HRC that withstands temperatures up to 900°C. The triple-flute C-profile cutting edge delivers 2× the cutting speed of standard step drills with enhanced stability and reduced deviation. Fits any drill with a 1/4" hex chuck.

Key Features

• 9 Step Sizes: 4, 5, 6, 7, 8, 9, 10, 11, 12mm — one bit replaces nine; no swapping required
• M35 Cobalt HSS — superior hardness, toughness and bending strength vs standard HSS; ideal for harder materials
• AlTiN Coating (89 HRC) — aluminium titanium nitride; resists heat up to 900°C, wear and corrosion; outlasts black oxide coatings
• Triple-Flute Spiral Design — enhanced stability; reduces deviation during cutting
• C-Profile Cutting Edge — smoother cutting; 2× faster than standard step drills
• 1/4" Hex Shank — fits standard drill chucks and quick-release hex chuck systems
• 145mm Overall Length

Compatible Materials

• Mild steel and medium hardness steel (plate up to 3mm)
• Stainless steel (plate up to 1mm)
• Aluminium, brass, copper and cast iron
• Galvanised pipe and low-carbon steel
• Plastic

Usage Tips

• Use low speed and light pressure until reaching the desired depth
• Apply cutting oil or water-soluble lubricant to reduce friction, heat and debris
• Start-up speed may be slower due to the larger cutting angle — this is normal