Drilling into metal rewards preparation more than raw force. The wrong bit glazing, wandering, snapping, or refusing to bite at all. Choosing among the many types of drill bit for metal comes down to three things: the material you’re cutting, the hole size you need, and how often you’ll repeat the job. Cobalt and titanium-coated HSS (high-speed steel) bits handle the heat of harder alloys, while stepped bits shine for sheet metal and conduit. Hobbyists can get away with a small titanium set, but anyone running stainless or production work reaches for M35 cobalt fast. Below, the roundup covers full jobber sets, stepped unibits, and specialty spirals, so you can match the tool to the task instead of guessing at the shelf.
The Picks In Brief
Chicago-Latrobe 550 Cobalt Jobber Drill Bit Set
IRONANT Cobalt M35 Spiral Flute Step Bit 3/16 to 7/8 in.
IRONANT 5-Piece HSS Titanium Step Drill Bit Set
IRONANT 5-Piece Spiral Flute Titanium HSS Step Drill Bit Set
IRONANT 3-Piece HSS Step Drill Bit Set Titanium Unibit
IRONANT Cobalt M35 Spiral Flute Step Bit 3/16 to 1/2 in.
IRONANT 3-Piece Cobalt M35 Spiral Flute Step Drill Bit Set
IRONANT M35 Large Step Drill Bit 1-3/8 in. Unibit
A full 115-piece cobalt jobber set in a metal index case is the kind of kit that quietly carries a workshop for years. Unlike the stepped unibits on this list, the Chicago-Latrobe 550 series uses individual round-shank twist bits sized from 1/16 inch up to 1/2 inch, including lettered and numbered fractional sizes that fabricators rely on. Cobalt construction helps the bits shrug off the heat that builds up when you push through stainless or hardened steel. You probably won’t need every size the day it arrives, but missing a single odd dimension in the middle of a job is frustrating enough to justify the case.
Home machinists and small-shop fabricators get the most mileage from a set this broad. It also covers plumbing and electrical rough-in work where tapped holes in sheet metal are routine.
Practical Advantages
- Individual bits stay sharper longer under heavy feed pressure than most titanium-coated general-purpose bits.
- Comprehensive size range covers the odd fractional and lettered dimensions that hobby sets often skip.
- Thicker web design helps the bit resist deflection when you lean into stainless plate.
- Metal index case keeps the set organized and makes missing a size obvious at a glance.
Trade Offs
- The 115-piece count means you’ll likely never use many sizes, so storage space matters.
- Cobalt jobbers excel at through-holes but aren’t a substitute for stepped bits in thin sheet metal.
Key Product Details
Right Fit For
Shop owners, fabricators, and serious hobbyists who want one set that handles almost any round hole size in metal.
Skip It When
Mostly drilling thin sheet metal or conduit, in which case the IRONANT 5PCS HSS Titanium Step Drill Bit Set covers the same ground with less weight and clutter.
Step bits earn their keep when you need several hole sizes from one tool, and the IRONANT M35 version pushes that convenience into stainless territory. M35 refers to a high-speed steel alloyed with 5 percent cobalt, which keeps the cutting edge harder at the temperatures generated by tougher alloys. A TiAlN coating (titanium aluminum nitride, a ceramic-style film that reduces friction and heat) further protects the flutes when you’re working in sheet stainless. The four spiral flutes lift chips away from the cut, which matters when the swarf would otherwise pack in and scorch the work.
Auto fabrication, stainless sheet work, and HVAC fabrication all line up well with this bit. Tradespeople drilling repetitive stepped holes in stainless enclosures will appreciate the durability.
Useful Touches
- Cobalt M35 body handles stainless without losing its edge as quickly as plain HSS.
- TiAlN coating reduces heat buildup during longer cuts in tough alloys.
- Four spiral flutes pull chips up and out, which helps when drilling thicker plate.
- 118-degree split point keeps the bit from walking when you start the hole.
Worth Noting
- Coated bits should not be resharpened the same way as bare HSS, so a dull bit usually means replacement.
- A single bit covers 3/16 to 7/8 inch, so very large holes still need a different tool.
Feature Snapshot
Whose Shelf It Belongs On
Tradespeople and DIYers working regularly in stainless sheet, exhaust components, or thicker steel plate.
Reach For A Different Pick When
Most jobs are light sheet metal and aluminum, where the IRONANT 5PCS HSS Titanium Step Drill Bit Set handles the work at a friendlier cost.
Stepped unibits live or die by their chip-clearing geometry, and the IRONANT titanium-coated set keeps things simple for the casual user. Each bit stacks multiple diameters on a single tool, so swapping to find the right size is faster than fumbling through a jobber index. The titanium coating extends tool life over plain high-speed steel, though it doesn’t perform the same role as a TiAlN layer on true stainless work. Compared with the cobalt picks in this list, this set trades cutting aggression for a more approachable price.
Weekend DIYers, electricians running conduit, and homeowners punching holes in sheet metal for vents or boxes are the natural fit.
Points In Its Favor
- Five bits cover a wide spread of common stepped sizes for sheet metal work.
- Titanium coating helps bits last longer in mild steel and aluminum.
- Single-bit design means fewer pieces to lose in a busy toolbox.
- Dual-flute geometry reduces the climbing pressure on a hand drill.
Soft Spots
- Not recommended for stainless steel, so its specialty is narrower than the cobalt picks above.
- Cutting fluid becomes more important for keeping the coating from wearing prematurely on thicker stock.
Best Suited To
Light-duty sheet metal projects around the house, including electrical boxes, vent cuts, and aluminum flashing.
Consider Something Else When
Stainless or hard alloys are in the mix, where the IRONANT Cobalt M35 Spiral Flute Step Bit 3/16 to 7/8 in. earns its keep.
Where the budget titanium set uses straight dual flutes, this IRONANT 5-piece version steps up to a spiral flute design. That shape pulls chips up and away from the cut rather than letting them stack at the bottom of the hole, which matters in deeper or stickier materials. The titanium coating still leans toward aluminum and mild steel rather than stainless, so it sits between the plain HSS picks and the true cobalt workhorses on this list. With 50 stepped sizes distributed across the five bits, the spread covers most common hole sizes in sheet metal.
Tradespeople running repetitive stepped holes in junction boxes, brackets, and ductwork benefit from the better chip evacuation.
A Favorable Mix
- Spiral flute geometry clears chips faster than straight flutes, reducing heat in the cut.
- Five-bit layout totals 50 sizes, covering most small- to mid-range stepped holes.
- Titanium coating adds useful life over bare HSS at modest cost.
- 118-degree split point minimizes walking on startup.
Points To Note
- Still not aimed at stainless steel, so heavier alloys need the M35 picks.
- Spiral flutes cut a touch more aggressively, so light feed pressure helps avoid grabbing thin sheet.
Who Will Love This
Regular sheet-metal users who want a step up from a basic titanium set without jumping to cobalt pricing.
A Better Fit Elsewhere
Anyone working mostly stainless should skip this for the IRONANT 3-Piece Cobalt M35 Spiral Flute Step Drill Bit Set.
Three bits are often all a first-time step-bit user really needs, which is exactly what IRONANT offers here. The largest bit alone runs through 13 stepped sizes from 1/8 inch up to 1/2 inch, so most small electrical and plumbing holes come out of a single tool. The titanium coating and 118-degree split point do their best to keep the cut centered and the flute clean. It costs less than the 5-piece spiral sets while still covering the most common diameter range a homeowner is likely to need.
Newcomers to step bits, occasional handymen, and anyone putting together a small starter kit get a friendly entry point.
Noteworthy Benefits
- Compact three-bit set keeps the toolbox light while still covering common sizes.
- Single largest bit covers a generous 13-step range from 1/8 to 1/2 inch.
- Titanium coating extends life over bare HSS at a low cost.
- Split point tip helps the bit stay where you start it on shiny metal.
Honest Caveats
- Three bits can run thin on coverage for larger conduit or panel work.
- Not suited to stainless or thick plate, where heat builds beyond the coating’s tolerance.
Made For
First-time step-bit users and homeowners who only need a handful of stepped sizes for occasional sheet-metal jobs.
Look Elsewhere When
You need a wider size spread in one go, in which case the IRONANT 5-Piece HSS Titanium Step Drill Bit Set extends the range without much extra weight.
Most electrical and plumbing holes fall inside a fairly small diameter window, and this IRONANT cobalt bit covers that sweet spot cleanly. The 3/16 to 1/2 inch range handles everything from pilot holes up to standard conduit knockouts without dragging along a long bit you rarely need. Cobalt M35 with a TiAlN coating keeps the edge cool enough to push through stainless junction boxes or thicker steel plates where a standard titanium bit would glaze. Spiral flutes finish the chip-clearing job, so the bit doesn’t pack up halfway through the cut.
Electricians, low-voltage installers, and HVAC techs who repeatedly drill the same small stepped range get a tidy specialty tool.
Everyday Advantages
- Compact size range matches the holes most service trades actually drill.
- Cobalt M35 body tolerates stainless for specialty enclosure work.
- TiAlN coating reduces heat at the cutting edge on longer cuts.
- Spiral flutes keep the cut clear, which matters in deeper electrical box walls.
A Few Limitations
- Not the right choice once hole sizes cross 1/2 inch, where larger step bits or hole saws take over.
- A single specialty bit costs more than a 3-piece titanium set covering similar ground in mild steel.
Quick Facts
Perfect Match For
Tradespeople repeatedly drilling small stepped holes in tougher metals, including stainless enclosures.
Not Your Match When
Most of your work is mild steel or aluminum, where the IRONANT 3-Piece HSS Step Drill Bit Set does the job at a lower cost.
A three-bit cobalt M35 set is a smart middle ground for a workshop that runs daily, but not exclusively, on stainless or thick plate. Each bit covers a different slice of the diameter range, from 1/8 inch up to 7/8 inch, so you get the cobalt durability in more sizes than a single specialty bit offers. The TiAlN coating and four spiral flutes do the same job they do on the single-bit M35 picks, just multiplied across a set. Compared with the 5-piece titanium sets, this is the one you’d reach for when the work gets harder and the cuts run hotter.
Fabrication shops, auto restorers, and serious DIYers with regular stainless or thicker steel work benefit most from this set.
A Few Strong Suits
- Cobalt M35 build holds an edge in stainless where titanium coatings glaze.
- Three-bit range covers small pilot holes through larger conduit sizes.
- TiAlN coating reduces friction during long cuts in tough alloys.
- Spiral flutes evacuate chips that would otherwise burn the cut surface.
Points To Keep In Mind
- Higher material and coating cost than the titanium HSS sets, so light-duty users pay for capability they won’t use.
- Replacing any single bit is more expensive than swapping a titanium unibit.
Right Fit For
Busy home workshops and small fabrication spaces that routinely cut stainless or thicker steel plate.
Swap It Out When
Your drilling stays in aluminum, copper, and mild steel, where the IRONANT 5-Piece HSS Titanium Step Drill Bit Set handles daily work more economically.
Big holes need different tools, and this IRONANT M35 step bit handles diameters that smaller unibits simply can’t reach. Stepped from 7/8 inch up to 1-3/8 inch, it covers oversized conduit knockouts, junction box penetrations, and large panel cutouts in a single pass. The cobalt body and TiAlN coating that the smaller M35 picks use show up here too, so the bit tolerates the heat that large-diameter cuts generate. Owners commonly note that without a pilot dimmer on the starter step, the bit can walk on slick metal, so a center punch pays off.
Electricians running large conduit, metalworkers building control panels, and HVAC fabricators punching duct penetrations are the natural users.
Positive Takeaways
- Reaches diameters that most stepped bit sets cap out well below.
- M35 cobalt body keeps cutting under the heat load of large holes.
- TiAlN coating slows wear during long cuts in stainless or thick plate.
- Spiral flutes clear the heavier chip volume that big cuts produce.
Things To Consider
- Larger diameter means more torque, so a steady drill press or a low-speed corded drill helps.
- Replacement is pricier than for smaller bits, so storing it safely is worth the effort.
Made For
Trades and shops that regularly drill large-diameter holes in metal and want one tool to cover the range.
Where Another Pick Suits Better
Smaller repeated holes dominate your day, in which case the IRONANT 3-Piece Cobalt M35 Spiral Flute Step Drill Bit Set covers the high-frequency sizes more practically.
## What To Weigh Before Picking Drill Bits For Metal ### Match The Bit Material To The Stock High-speed steel handles mild steel, aluminum, and copper with ease, while cobalt M35 earns its keep on stainless and thicker alloys that build heat fast. Titanium and TiAlN coatings extend bit life by lowering friction, but they don’t transform plain HSS into a stainless-cutting tool. For occasional DIY work in thin metal, a titanium-coated HSS set is plenty. For production or stainless, cobalt becomes a practical upgrade rather than a luxury. ### Understand Why Geometry Matters Point angle, flute shape, and split-point design all influence how a bit starts, cuts, and clears chips. A 118-degree split point reduces walking on slick surfaces, while spiral flutes evacuate chips more aggressively than straight ones. Stepped unibits shine for sheet metal and conduit because one tool replaces a stack of individual bits. Twist jobbers win when hole size varies widely across a project. ### Right Size For The Job Buying the largest set you can afford isn’t always the smartest move. A 115-piece cobalt jobber set covers almost any round hole, yet the bulk and weight are wasted if you only need a handful of common diameters. A 3-piece titanium set or one or two specialty step bits often covers a homeowner’s needs without dominating the drawer. Match the range to your real workload. ### Speed, Pressure, And Lubrication Even the best bit burns up fast when run too hot. Slower speeds, steady feed pressure, and a drop of cutting fluid on steel and stainless extend tool life noticeably. Stepped bits especially benefit from light pressure so each step can clear before the next one engages. Owners commonly find that patience and lubrication do more for bit longevity than any coating claim. ## Sharp Edges To Watch In This Category ### Mistakes Worth Dodging Buying HSS bits expecting them to handle stainless is the most common trap in this category. The bit appears to cut at first, then quickly overheats and loses its edge. A related slip is treating titanium coating like a magic shield: the coating slows wear but doesn’t make a soft bit suitable for hard alloys. Skipping a center punch on smooth or polished stock is another easy mistake, since split-point geometry helps but doesn’t always prevent walking on its own. ### Where The Extra Money Goes The jump from a titanium HSS set to a cobalt M35 set reflects real material and coating upgrades, not just branding. Cobalt stays hard at the temperatures generated by stainless, and TiAlN coatings reduce friction on long cuts. Spiral flutes also cost more to grind than straight ones, but they evacuate chips that would otherwise scorch the work. The upgrade pays off when you cut stainless, thick plate, or run repetitive production cuts. For occasional thin sheet metal, the titanium tier is plenty.
