Clean, Controlled Multi-Size Holes in Sheet Metal

Sutton Tools step drills give electricians, fabricators, installers & maintenance crews a practical way to drill multiple hole diameters with a single cutting tool. Built from M2 high-speed steel, Sutton HSS step drill bits use fixed drilling steps & a spiral flute design to provide greater control through each step while reducing vibration.

Ideal for sheet metal, aluminium, plastic & fibreglass, these step drills can produce progressively larger holes without requiring a separate drill bit for every diameter. They're particularly useful in fabrication, electrical installation, switchboard work, automotive applications & workshop jobs where accurate hole sizing matters.

Need the driving tool as well? Compare  Drills for suitable workshop & trade drilling equipment.

What Are Sutton Tools Step Drills?

A step drill bit uses a tapered profile containing multiple fixed diameter steps rather than one continuous cutting diameter.

As the drill advances through suitable material, each successive step increases the hole to the next defined size. That allows one bit to cover multiple hole diameters within its specified range.

Sutton's D504 HSS step drills are available across numerous metric & imperial configurations, including ranges such as 4–12mm, 4–20mm, 4–22mm, 4–25mm, 4–30mm, 5–35mm & 6–36mm, depending on the individual model.

The range is manufactured from M2 High Speed Steel, which Sutton specifies for its combination of strength, heat resistance & wear resistance. A three-flat shank is designed to suit 3-jaw chucks while the spiral flute assists control as the cutter progresses through its steps.

Why Choose Sutton Step Drill Bits?

One hole might need to take a cable gland. The next could be for a switch, fitting, fastener or control component. That's where the stepped design becomes particularly useful.

Multiple Diameters From One Drill Bit

Instead of changing between numerous conventional drill sizes, a step drill allows the operator to progressively enlarge the opening until the required step is reached.

That versatility can be particularly useful for tradespeople working across different hole sizes during installation & fabrication.

No Pre-Drilling Required in Sheet Metal

Sutton identifies its HSS step drills as ideal for drilling sheet metal without pre-drilling.

That makes them especially relevant for electrical, fabrication & maintenance work where new openings need to be produced efficiently in suitable sheet material.

Spiral Flute for Better Control

Sutton's spiral-flute design is intended to reduce vibration & provide greater control as the cutter moves through successive steps.

Greater control matters when the target isn't simply making a hole — it's stopping cleanly at the required diameter.

Deburring Happens as You Progress

A useful feature of the stepped geometry is that the following step deburrs the previously drilled hole as drilling progresses.

That can streamline suitable sheet-metal drilling tasks where both sizing & edge finish matter.

M2 High-Speed Steel Construction

Material choice matters once a cutting tool is put into regular workshop use.

Sutton specifies M2 HSS for these drills, providing a balance of strength, heat resistance & wear resistance for their intended applications.

For businesses building out a broader drilling setup,  Drill Accessories provides a natural next stop for complementary equipment.

Common Applications for Step Drills

Step drills earn their place when trades need controlled hole sizing in relatively thin materials rather than deep-hole drilling.

► Electrical installation — creating or enlarging suitable openings for glands, conduit fittings & components.
► Switchboards & enclosures — producing different hole diameters in suitable sheet material.

► Metal fabrication — drilling progressive hole sizes during workshop fabrication.
► Automotive work — making controlled openings in suitable panels & sheet materials.
► HVAC installation — preparing holes for fittings, controls & associated installation work.
► Maintenance departments — keeping one multi-diameter drilling tool available for varied repair & modification jobs.
► Plastic & fibreglass work — Sutton also lists these materials among the intended applications for its HSS step drills.

Electricians putting together a more complete field setup can also explore  Electrical Tool Kits.

For apprentices still building out their core trade kit, The Apprentice's First Tool Kit: What You Actually Need provides useful broader guidance on prioritising tools that earn their place on the job.

Product Selection Guide – Choosing the Right Sutton Step Drill

Start with the smallest & largest hole diameter you expect to drill regularly.

Buying a step drill with the wrong range can leave the required diameter outside the tool's available steps or result in carrying more cutting capacity than the job needs.

Match the Diameter Range

Sutton offers multiple D504 configurations rather than a single universal step drill.

Available metric ranges include options covering:

► 4–12mm
► 4–20m
► 4–22mm
► 4–25mm
► 4–30mm
► 5–35mm
► 6–18mm
► 6–36mm

Imperial configurations are also available in the wider Sutton range.

Check the Number of Steps

Two drills can cover similar overall dimensions while providing different intermediate sizes.

For example, Sutton lists both a 5-step 4–12mm option & a 9-step 4–12mm configuration. Check the individual diameters rather than purchasing solely from the minimum & maximum range printed on the product.

Individual Drill or Set?

Trades that repeatedly work within one diameter range may only require a single step drill.

For broader workshop coverage, Sutton also offers a three-piece HSS step drill set covering 4–12mm, 4–20mm & 4–30mm ranges.

That can be a more practical choice for technicians who encounter varying hole sizes across different jobs.

Confirm the Material

Sutton identifies the D504 range for sheet metal, aluminium, plastic & fibreglass.

Don't assume a step drill intended for these applications replaces dedicated tooling for every material or drilling situation.

When the job expands beyond stepped holes, Power Tool Accessories provides access to the wider accessory range.

Expert Tips for Cleaner Step Drilling

A good step drill gives you the sizing options. Technique determines how well you use them.

Mark the required diameter before starting. Knowing exactly which step you're aiming for reduces the chance of drilling one size too far.

Keep the drill controlled. Let each cutting step work progressively rather than forcing the tool through the material.

Watch the next step carefully. Once the required diameter has been reached, unnecessary further advancement can enlarge the opening beyond specification.

Secure the workpiece properly. Loose sheet material can move during drilling, reducing control & creating an avoidable workshop hazard.

Inspect the material before cutting. Confirm the step drill is appropriate for the workpiece rather than assuming one cutting tool suits every substrate.

Pay attention to heat & cutting performance. Cutting conditions influence tool performance & life, particularly during repeated metal drilling.

Protect the cutting edges in storage. Throwing cutting tools loose into a drawer can expose them to unnecessary contact & damage.

For tradespeople reviewing broader tool-care habits, A tool is not just a tool. It’s a promise. looks at the value of dependable equipment in day-to-day trade work.

Workshop teams can also pair drilling equipment with Clamps & Vises where appropriate workpiece holding is required.