3-Plate / 6-Edge SDS-Max Drill Bits — the Round-Hole Architecture, Factory-Direct
Program Overview
The 3-plate / 6-cutting-edge SDS-Max head — the architecture behind the Diager Ultimax 168 and the DeWalt mining bits Latin America calls broca francesa — drills round, diameter-calibrated, straight deep holes that flat-tipped bits cannot match on rock. Zhonghuan manufactures this head type in-house: three controlled-atmosphere brazed virgin carbide plates around a self-centering point, on a progressive 42CrMo body, in mining lengths to 920 mm — supplied factory-direct as an OEM / private label program for mining and fastening distributors.
What the Geometry Buys You
| Design element | Function |
|---|---|
| 3 carbide plates / 6 cutting edges | Each blow is shared across six contact lines — no single edge takes the full hit on uneven rock; the bore stays concentric and holds nominal gauge |
| Self-centering point | Engages first and anchors the bit — no walking on sloped or fractured collars, clean spot drilling at 15° into a face |
| Progressive core | Body diameter steps up along the flute — bending resistance for 920 mm bits driven off-axis by hand |
| Wide-spiral deep-hole flutes | Clears coarse rock cuttings in deep dry holes — the main defence against packed-dust overheating |
How this family compares against full carbide head construction — and how to word an RFQ so 6-cutter / 3-plate / full-head never get confused — is covered in our 3-plate / 6-edge vs full carbide head guide. The brand-level story of the benchmark line is in the Diager Ultimax 168 analysis.
Size Program
| Spec | Range | Notes |
|---|---|---|
| Diameter | Ø28–38 mm (Ø32 is the mining volume size) | 32 mm hole fits ø25 mm (1") cartridges with working clearance |
| Total length | 450 / 570 / 620 / 920 mm | Covers the Diager and DeWalt mining length systems; specify working length when hole depth is the requirement |
| Shank | SDS-Max | Fits all SDS-Max rotary hammers; SDS-Plus per project |
| Carbide | Controlled-atmosphere brazed virgin carbide, YG11C class | Ceratizit tips available with supplier mill certificate |
| Body | 42CrMo, progressive core, heat treated | Multi-stage: normalizing, quenching, annealing, stress relieving |
Application Scenarios
1. Mining Blast-Hole Drilling
Material: Medium to hard rock at the working face
Recommended: Ø32 × 620 / 920 mm
Notes: The volume application. Round, full-gauge, straight holes let ø25 mm cartridges seat fully in 450–800 mm holes; retire bits on gauge wear. Field engineering in the blast-hole drilling guide; the wider program on the SDS-Max mining drill bits page.
2. Deep Anchor and Dowel Holes
Material: Concrete, stone, hard masonry
Recommended: Ø28–32 mm, length per embedment + 50 mm
Notes: Diameter-calibrated holes drive anchor pull-out values — the same property the head was designed for. Six edges also tolerate incidental rebar contact better than a flat two-edge tip.
3. Service Penetrations in Masonry and Stone
Material: Brick, block, rubble masonry, natural stone walls
Recommended: Ø28–38 mm, lengths to 920 mm
Notes: Pipe and cable through-holes in old, inconsistent walls reward the self-centering point and distributed impact — mixed material is where flat tips chip.
OEM & First-Order Terms
- MOQ: 200 pcs per size
- Samples: Paid samples; sample and shipping cost carried by the buyer; ~30 days sample lead after confirmation
- Production timing: Confirmed after specification and capacity review at order placement
- Branding: Laser-etched logo + custom packaging (bulk / blister / branded box)
- Quality: ISO 9001; material certificates with every shipment; Ceratizit carbide option with supplier mill certificate
Benchmarking Against the Ultimax 168 Class?
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