What the Ultimax 168 Is
The Diager Ultimax SDS-Max line — reference format 168D, as in 168D32L0920 (Ø32 mm, 780 mm working length, 920 mm total) — is a French-made hammer drill bit built around one idea: three carbide plates forming six cutting edges around a self-centering point, on a progressive core with a spiral engineered for fast dust extraction and resistance to point bending.
Two reference codes are easy to confuse at dealers: 168D = Ultimax 168, the 3-plate / 6-edge line this article covers; 166D = Ultimax 646, a different and higher tier — a massive carbide head with 10 cutters, six lateral stabilisers and an elliptical 130° tip, built for the most rebar-dense concrete. The 168 catalog itself spans Ø12–52 mm, with total lengths from 340 mm up to 3,850 mm — the XXL sizes dealers list as “4000 mm” (168D22L3850 / 168D25L3850, 3,580 mm working length).
Diager's catalog language is disarmingly practical: round and calibrated holes, self-centering plunge, optimal transfer of impact energy, low vibration, long life. No drama — just the properties that matter when the hole itself is the product.
In the Andean mining trade this architecture has a different name entirely: it is the head behind what buyers call the broca francesa — and when a Peruvian distributor recently sent us their benchmark sheets for a private-label mining program, the French-made 6-edge bit was the reference everything else was measured against. That market story is told in our broca francesa vs broca alemana analysis; this article is about the head itself.
The Geometry: Why 3 Plates and 6 Edges
A standard SDS-Max bit carries one wide carbide insert (2 cutting edges) or a flat 4-cutter cross. The Ultimax head splits the carbide into three separate plates, each presenting two edges — six in total — arranged around a raised centering point. Three consequences follow:
1. Impact distribution. Each hammer blow is shared across six contact lines instead of two or four. On an uneven rock collar — where the first contact lands on one corner of the head at full impact energy — no single edge absorbs the whole hit. This is the chipping-resistance mechanism, and it is why the geometry survives rock faces that break flat-tipped concrete bits.
2. Round, calibrated holes. Six edges sweeping the bore produce a more concentric hole that holds its nominal diameter — Diager's catalog explicitly promises holes calibrated to diameter. In anchor work that means dowel pull-out values; in mining it means a ø25 mm cartridge slides to the bottom of a 32 mm hole instead of jamming on an out-of-round section.
3. Self-centering on bad surfaces. The center point engages first and anchors the bit before the plates touch, so the bit does not walk on sloped or fractured collars. Hand-held drilling at 15° into a blast face is exactly the situation this solves.
Under the head, the progressive core — body diameter stepping up along the flute — resists the point-bending loads of long bits driven off-axis by hand, and the wide spiral clears coarse rock cuttings rather than fine concrete dust. The architecture is coherent top to bottom: everything serves deep, straight, round holes in non-ideal material.
The Line: References, Sizes, Lengths
| Reference (examples) | Size | Note |
|---|---|---|
| 830200 (entry of range) | 12 × 200 × 340 mm | Line starts at small anchor diameters |
| 168D28L0920 | 28 × 920 mm | Mining-length format |
| 168D32L0920 | 32 × 780 × 920 mm | The blast-hole size; note 780 mm usable length on the 920 format |
Two details worth a buyer's attention. First, the usable length: Diager lists 780 mm working length on the 32 × 920 — slightly under the 800 mm that DeWalt's equivalent format quotes — a reminder to specify working length, not total, when an 800 mm hole is the requirement. Second, the reference logic (16xD + diameter + L + total length) makes the family easy to audit across dealer listings, which is how we assembled the pricing picture below.
Catalog Says Rebar — the Field Says Blast Holes
Diager's official applications for the line are construction: fixing steel rebar (dowelling) and passage of pipes or electrical cable. Nothing about mining.
The mining adoption happened in the field, for a geometric reason: the properties that make a perfect dowel hole — round, calibrated, straight, full-depth — are the same properties that make a chargeable blast hole. Small-scale miners drilling 32 mm × up to 800 mm holes with 10 kg rotary hammers discovered that the 6-edge head holds gauge in abrasive rock and keeps deep holes on line, and the trade built a vocabulary around it (broca francesa, the French bit). The full field engineering — hole-to-cartridge sizing, wear modes, cost per metre — is in our blast-hole drilling guide.
Ultimax 168 vs Ultimax-G
Diager today runs two Ultimax generations side by side, and they solve different problems:
| Ultimax (168D, this article) | Ultimax-G | |
|---|---|---|
| Architecture | 3 plates / 6 edges + centering point, progressive core | Diager’s newer premium reinforced-concrete head |
| Optimized for | Hole roundness, calibration, depth — rock and masonry | Rebar engagement and speed in structural concrete |
| Field constituency | Anchoring contractors; hand-held mining | Heavy construction in reinforced concrete |
We compared the Ultimax-G against its German rival in Heller TriJET Ultimate vs Diager Ultimax-G. The short version: the G belongs in the rebar conversation; the 168 belongs in the rock conversation. Confusing the two leads distributors to stock the wrong bit for their market.
What It Retails For Worldwide
The 168 family is distributed and premium-priced on every continent we checked (street prices, VAT-inclusive where shown, mid-2026):
| Market | Size | Observed retail |
|---|---|---|
| Germany (dealer shop) | 28 × 920 mm | ≈€158 gross / €129 net |
| Japan (Amazon marketplace) | 32 × 780 × 920 mm | ≈¥28,000 |
| Thailand (tool retailer) | 12 × 340 mm (entry) and up | from ≈฿1,580, range tops ฿50,000+ |
Two readings. For end users: a 920 mm mining-length bit in this architecture costs roughly €130–180 at retail in developed markets. For distributors: that price band — multiplied by the consumption rate of abrasive-rock drilling — is precisely the margin pool that private-label mining programs are built against, which is why the Peruvian benchmark sheets we received quoted this family and not a budget line.
The OEM-Equivalent Program
The 3-plate / 6-edge architecture is specifiable, and Zhonghuan manufactures it in-house as our 6-edge mining head:
- Head: three controlled-atmosphere brazed virgin carbide plates, six cutting edges, self-centering geometry — YG11C-class carbide for SDS-Max diameters; Ceratizit tips available with mill certificate.
- Body: progressive 42CrMo heat-treated body, wide-spiral deep-hole flutes.
- Sizes: Ø22–45 mm, total lengths 450 / 570 / 620 / 920 mm — covering both the Diager and DeWalt mining length systems; other sizes by drawing.
- Program: MOQ 200 pcs per size, paid samples (~30 days), laser-etched private label, ISO 9001 with material certificates.
Full specifications, hammer compatibility and application scenarios are on the 3-plate / 6-edge manufacturer page and the wider SDS-Max mining drill bits program. For where this head sits among the other SDS-Max architectures, see the ZHMAX geometry guide.
