Same Head, Two Grinds
Start with what does not change. Both bits here are a full carbide head: the entire cutting head is one sintered piece of tungsten carbide, resistance friction-welded to the steel body, with no brazed inserts and no silver-braze seam to fatigue under impact. Same construction, same YG11C grade, same seam-free durability, same Ø3–20 mm SDS-Plus range. The only thing that changes is how the one-piece head is ground — to three cutting edges at 120° (a Y), or to four at 90° (a cross). That single geometric choice is the whole decision.
4-Cutter (Cross, 90°): Roundest Holes, Best Anchor Precision
Four edges in a symmetric cross balance the cutting forces around the axis. More edges ride the hole wall and the symmetry cancels side load, so the 4-cutter grind drills the roundest, most dimensionally accurate hole and starts with the most precise positioning. In clean, unreinforced concrete it is also the fastest — four edges remove more material per revolution with less single-edge thrust. When the job is precise anchor holes in sound concrete, where hole roundness drives anchor pull-out, the 4-cutter full carbide head is the pick. This is the geometry on the right of the image above.
3-Cutter (Y, 120°): Self-Centering and Rebar-Steady
Three edges at 120° form a triangle — the minimum stable contact set — so at least two edges are engaged at every instant. That buys two things a symmetric 4-cutter cannot match. It self-centers hard on smooth or sloped starts without walking; and it stays steady when an edge meets rebar — instead of grabbing and deflecting, the Y keeps the bit centered and shears through the bar. This is the grind for expected rebar contact and awkward starts: the 120° three-point is the rebar-tolerant, anti-jam geometry. It trades a little of the 4-cutter's clean-concrete speed and hole-wall polish for that stability. This is the geometry on the left of the image above.
Which to Grind for Which Job
| The job | Grind to pick |
|---|---|
| Precise anchor holes in sound concrete | 4-cutter |
| Clean / unreinforced concrete, maximum speed | 4-cutter |
| Rebar contact expected (anchors near bars, post-installed rebar) | 3-cutter |
| Awkward, sloped or smooth-surface starts | 3-cutter |
| Steel deck-plate pass-through | 3-cutter |
| General mixed concrete | Either — 4-cutter for roundness, 3-cutter for rebar safety |
What They Share (Because Both Are Full Carbide Head)
Whichever grind you choose, the full-carbide-head construction gives both a baseline brazed-tip bits cannot: no braze joint to crack, a head that holds its gauge several times longer, and one-piece carbide that survives rebar strikes without losing a tip. Both run YG11C full-carbide-head grade (the heaviest-impact grade), a 40Cr body (42CrMo option), and Ø3–20 mm SDS-Plus. So the 3-vs-4 decision is about hole character and rebar behaviour — not durability, which both share. For the deeper construction story, see the 3-cutter full carbide head guide.
OEM & Private-Label
Zhonghuan manufactures both grinds — 3-cutter (Y) and 4-cutter (cross) full carbide head — under OEM and private-label programs, with documented grade, weld method and runout inspection. Contact Zhonghuan Tools with your diameter range and application for a sample plan and quotation.
Related Procurement Programs
Sourcing full carbide head SDS for a distributor or private-label channel? These OEM programs cover both grinds.
- 3-Cutter Full Carbide Head SDS-Plus Manufacturer — OEM / private-label for the 3-cutter (Y) grind.
- Y-Cutter SDS Drill Bits Manufacturer & OEM — the 3-blade 120° geometry as a Heller-Trijet-class OEM line.
- Full Carbide Head SDS-Plus Drill Bits Manufacturer — the full-carbide-head program both grinds belong to.
