Annular Cutters
Core cutters for magnetic drilling — they cut only the annulus and eject the slug, making a clean, accurate hole in a fraction of the energy a twist drill needs. Standard Weldon 19.05mm shank fits virtually any mag drill; three series — HSS, M42 cobalt, brazed TCT — matched to your steel grade and duty cycle.
Product Series
Steel grade is the decision. Mild structural steel, stainless, and hardened or abrasive steel each demand a different cutting edge. Choose the series built for the steel you actually cut — and the duty cycle you run it at.
HSS Annular Cutter (M2)
M2 high-speed steel with a multi-tooth cutting geometry for mild and medium-carbon structural steel. The TiN gold coating lowers cutting temperature and resists built-up edge. Supplied with the matching pilot pin.
Cobalt Annular Cutter (M42)
M42 cobalt high-speed steel keeps its hardness at the higher temperatures generated when cutting stainless, duplex and high-tensile structural steel. The right call when M2 dulls or burns too fast.
TCT Annular Cutter (Carbide-Tipped)
Brazed tungsten-carbide teeth cut hardened, abrasive and high-tensile steel that destroys HSS — rail, spring steel, cast iron and weathered structural steel. Higher feed rates, far longer life, and enough toughness for the less-rigid setups of portable mag drills.
Technical Specifications
Key parameters by series — each matched to a steel grade and duty cycle
Common Diameters & Cutting Depths
Standard stock range across the three grades — custom diameters and depths available on OEM orders
| Diameter | Depth | Shank | Ideal For |
|---|---|---|---|
| Ø12–17mmØ1/2" - Ø11/16" | 25 / 50mm25 / 1-15/16" | Weldon 19.05mmWeldon 3/4" | Bolt holes in light structural steel |
| Ø18–26mmØ11/16" - Ø1" | 25 / 50mm25 / 1-15/16" | Weldon 19.05mmWeldon 3/4" | Standard structural connections |
| Ø27–40mmØ1-1/16" - Ø1-9/16" | 50mm1-15/16" | Weldon 19.05mmWeldon 3/4" | Large bolt and pin holes |
| Ø41–60mmØ1-5/8" - Ø2-3/8" | 50mm1-15/16" | Weldon 19.05mmWeldon 3/4" | Heavy fabrication, base plates |
| Ø61–100mmØ2-3/8" - Ø3-15/16" | 50 / 100mm50 / 3-15/16" | Weldon 31.75mmWeldon 1-1/4" | TCT only — large-diameter cuts |
Getting the Most From an Annular Cutter
Annular cutters cut differently from twist drills — these fundamentals decide tool life and hole quality.
Match the grade to the steel
HSS for mild structural steel, M42 cobalt for stainless and high-tensile, TCT for hardened, abrasive or rail steel. Running HSS in stainless burns the edge in minutes.
Tip · On stainless or steel above S355, step up to cobalt or carbide.
Use the pilot pin and coolant
The pilot pin centers the cut, ejects the slug and feeds coolant to the teeth. For HSS and cobalt, flood or internal coolant is essential — heat is what kills these cutters.
Tip · TCT can run near-dry on portable setups; HSS cannot.
Right speed, steady feed
Annular cutters run slower than twist drills — larger diameter means lower RPM. Feed steadily until a continuous chip forms: too light glazes the edge, too hard chips the teeth.
Tip · Let the cutter cut. A continuous curling chip is the target.
Secure the magnet
Mag-drill holding force needs a clean, flat steel surface of at least about 6mm. On thin or coated material, clamp the machine or fit the safety strap — a cutter grabbing on a weak magnet is the main failure mode.
Tip · Wire-brush mill scale and paint under the magnet base first.
Clear the slug
At the end of the cut the spring-loaded pilot ejects the slug. Keep the cutter bore and gullets clear of swarf between holes to reach full depth.
Tip · Hot slugs eject with force — keep the area below the workpiece clear.
Resharpen and replace pins
HSS and cobalt cutters can be resharpened several times and carbide teeth can be re-brazed. Replace the pilot pin once the slug stops ejecting cleanly.
Tip · Pilot pins are a low-cost consumable — keep spares for each cutting depth.
Wholesale & OEM Information
Wholesale and OEM support for global partners
Packaging Options
OEM/ODM Services
- — Custom diameter range (Ø12–100mm) and cutting depths
- — Material grade selection — M2 HSS, M42 cobalt, or carbide-tipped
- — Custom shank: Weldon 19.05mm, Weldon 31.75mm, Nitto one-touch, or quick-change
- — Coating options — TiN, TiAlN, TiCN
- — Laser engraving of company logo and diameter markings
- — Pilot pin length and specification matched to cutter depth and machine
- — Branded retail packaging: tube, printed box, set case, or master carton
Order Details
Frequently Asked Questions
What is an annular cutter and how is it different from a twist drill?
An annular cutter (also called a core cutter, broach cutter or mag-drill cutter) removes only a ring of material around the hole and leaves a solid slug in the center, which is ejected at the end of the cut. Because it cuts only the annulus instead of the full hole, it needs roughly one-third the power of an equivalent twist drill, runs faster, makes a cleaner and more accurate hole, and skips the large pre-drilling step. It is designed to run in a magnetic drilling machine.
Which grade should I choose — HSS, cobalt, or TCT?
Match the grade to the steel: (1) Mild and medium-carbon structural steel → HSS (M2). (2) Stainless, duplex, high-tensile or work-hardening steel → M42 cobalt, which holds its edge at higher temperatures. (3) Hardened, abrasive, rail or weathered steel, or jobs needing maximum tool life and high feed → TCT carbide-tipped. TCT also tolerates the less-rigid setups of portable mag drills and interrupted cuts.
What shank do your annular cutters use — will they fit my magnetic drill?
The standard is the Weldon 19.05mm (3/4") shank with two flats, which fits the large majority of magnetic drilling machines worldwide. Large-diameter cutters use a 31.75mm (1-1/4") Weldon shank. We can also supply Nitto/one-touch and quick-change shanks on request — tell us your machine model and we will confirm fitment.
What cutting depths are available?
Standard cutting (drilling) depths are 25mm and 50mm for HSS and cobalt, and 35, 50 and 100mm for TCT. The pilot pin must match the cutting depth, so a deeper cutter ships with the correct longer pilot pin. Custom depths are available on OEM orders.
Is the pilot pin included, and is it replaceable?
Yes. Every cutter ships with the matching pilot pin. The pilot pin centers the cutter at the start of the hole, feeds coolant to the cutting teeth, and ejects the slug at the end. It is a replaceable consumable — keep spares for each cutting depth, and replace it once the slug stops ejecting cleanly.
Can annular cutters cut stainless steel?
Yes — use the M42 cobalt series for austenitic stainless (304/316) and duplex, or the TCT series for harder grades. Stainless work-hardens quickly, so keep a steady feed (never dwell or rub), use generous coolant, and run a lower RPM. Plain M2 HSS dulls rapidly in stainless and is not recommended.
Can I run an annular cutter in a hand drill or a pillar drill?
Annular cutters are designed for magnetic drilling machines, which provide the rigidity and the Weldon arbor they need, so they are not suited to handheld drills. With a quick-change/keyless adapter some smaller cutters can be used in a rigid pillar/bench drill, but rigidity and accurate centering are critical — TCT tolerates less-rigid setups better than HSS.
Do you offer OEM annular cutter supply?
Yes. OEM options include custom diameter and depth ranges, grade selection (M2 HSS, M42 cobalt, carbide-tipped), shank type, coatings, laser engraving, and full retail packaging design. Contact us with your specification and destination market.
Not Sure Which Grade Your Steel Needs?
Tell us the steel grade, plate thickness, hole diameters and your mag-drill model — we'll confirm HSS, cobalt or TCT and the right cutting depth, and can arrange samples before a production order.
Related Products
Related Sourcing Guides
Top Annular Cutter Manufacturers (2026): Premium Brands and OEM Sourcing Shortlist
A buyer-focused shortlist of annular cutter (mag-drill core cutter) manufacturers for steel-fabrication distributors, importers, and OEM buyers. Covers Hougen, Fein/Jancy Slugger, Euroboor, Milwaukee, Nitto Kohki, and BDS, plus direct-from-factory OEM. HSS vs M42 cobalt vs TCT carbide grade guide, Weldon 19.05mm shank standards, and a procurement-ready RFQ template.
TCT Core Bits vs TCT Annular Cutters: Different Tools for Different Substrates
Technical disambiguation of TCT core bits (SDS-Plus / SDS-Max for concrete and masonry) and TCT annular cutters (Weldon-shank for steel on magnetic drills). Covers shank standards, carbide grade selection (impact vs shear), cutting mechanism, machine compatibility, and why the two products cannot substitute for each other.