VAJRA TOOLSMining & Industrial Diamond Drill Bits
Diamond grading, bit design and matrix composition, tuned through decades of testing across drilling conditions — so every VAJRATOOLS bit is built to the formation it will actually meet.
Vajra Tools has been manufacturing diamond drill bits and drilling accessories since 1987, with production running out of our Vasai works since 1989. What started as a small partnership has grown into a Mumbai-based manufacturer trusted across mining and construction — still privately held, still hands-on with every batch that leaves the works.
Registered as a partnership in Mumbai in January 1987 — 39 years and counting in diamond tooling.
Manufacturing out of our Vasai works since August 1989 — over 35 years of continuous output.
Independently assessed and certified for Quality Management Systems, scoped to diamond drill bit & drilling accessory manufacturing.
Every VAJRATOOLS bit balances diamond selection, waterway layout and crown profile against the formation it's cut for. International standards — DCDMA, CDA, Swedish, British, Russian — set the baseline; custom specifications take it from there.
Protrusion is set by diamond size — larger stones stand proud, smaller stones sit closer to the matrix. Manufacturing control keeps protrusion uniform across the crown.
Soft and medium rock call for more waterways to clear sludge; hard rock calls for fewer, for a more robust bit. We keep the count to the minimum the formation allows.
Exact stone positioning across the crown or reamer shell is drawn from master diamond patterns held for every bit type — precision that's repeatable, not eyeballed.
Most jobs call for the semi-round nose — our standard profile. Where the formation or the hole demands otherwise, we cut flat, semi-flat, two-step or three-step crowns to match.
Full flat face, standard bit.
Broad radius across a flat base.
Our standard — suits most drilling.
Staged face for fractured ground.
Progressive face for tough transitions.
Matrix hardness runs opposite to rock hardness — the tougher the rock, the softer and more self-sharpening the matrix needs to be so fresh diamond keeps exposing itself. Tap a grade below.
A full drilling string, in one house — core bits, casing bits, casing shoe bits and reamer shells to DCDMA and metric standard, plus industrial diamond core bits for concrete and construction work.
Normal concrete, masonry, tiles, natural stone — fast, clear holes.
Bitumen, abrasive concrete, refractories.
Heavily reinforced concrete and hard, abrasive formations under abuse.
A working slice of the DCDMA / metric size range. Full diamond-loading charts across every grit range are available on request.
| Size | Core Bit OD / ID | Reamer Shell OD |
|---|---|---|
| EX / EXT / EWT | 1.470" / 0.845–0.905" | 1.485" |
| AX / AXT / AWT | 1.875" / 1.185–1.281" | 1.890" |
| BX / BXT / BWT | 2.345" / 1.655–1.750" | 2.360" |
| NX / NXT / NWT | 2.965" / 2.313" | 2.980" |
| AQ | 1.875" / 1.062" | 1.890" |
| BQ | 2.345" / 1.433" | 2.360" |
| NQ | 2.965" / 1.875" | 2.890" |
| HQ | 3.765" / 2.500" | — |
| 46mm K3 | OD 1.811" / ID 0.945–1.457" | 1.826" |
| 66mm K3 | OD 2.598" / ID 1.496–2.244" | 2.613" |
| 101mm K3 | OD 3.976" / ID 2.835–3.504" | 3.991" |
| 146mm K3 | OD 5.748" / ID 4.567–5.276" | 5.763" |
Share the rock type, hole size and depth you're working with — we'll recommend a matrix grade and profile, or cut a bit to your own drawing.
Gupte House, Plot No. 376-A,
9th Road, Chembur, Mumbai - 400071
02, Godavari, Tungareshwar Industrial Estate,
Sativali, Vasai (E), 401208
Office — +91 99205 72423
Mobile — +91 98211 63423
DCDMA · CDA · Swedish · British · Russian · Custom specification on request