What Defines a Sintered Diamond Core Bit
Sintering is the volume-tier diamond segment manufacturing process. Synthetic diamond crystals are mixed with metal powders (cobalt, iron, copper, bronze) in a precise formula, then hot-pressed at high temperature and pressure (typically 700-900°C, 200-400 MPa) into a solid segment block. The diamond is distributed through the entire segment depth — not just at the cutting surface. As the metal matrix wears under cutting load, fresh diamond exposes, giving the tool a self-sharpening behavior across its lifetime.
For OEM procurement, the sintering process is the segment formation step. The segment then needs to be attached to a steel body — typically by silver brazing for 105-350 mm cutting wheels and small-diameter cores, sometimes by laser welding when the application requires heat survival. The attachment method matters as much as the sintering itself; specify both in the RFQ.
Zhonghuan Sintered Diamond Core Bit Spec
| Parameter | Standard Spec |
|---|---|
| Segment formation | Hot-pressed sintering, 700-900°C, 200-400 MPa |
| Matrix composition | Cobalt-iron-copper-bronze powder, formula per substrate |
| Diamond grit and concentration | US 30/40 to 50/60 typical, C20-C35 concentration |
| Segment-to-body attachment | Silver braze standard; laser weld available for premium specs |
| Diameter range | 105-350 mm volume tier |
| Segment height | 7-12 mm typical for cutting wheels, 9-10 mm for core bits |
| Matrix hardness verification | Rockwell C measurement on QC sample |
Recommended Sintered Core Bit Ranges
| Range | Specification | Channel Fit |
|---|---|---|
| Masonry handheld cores | Ø35–150 mm, 5/8-11 UNC, hard bond, 9 mm segment | Plumber, electrician, brick and block drilling |
| Cutting wheels for angle grinder | Ø100–230 mm, 22.23 mm arbor, soft-medium bond, 7-10 mm segment | DIY, entry-pro, masonry contractor |
| Wet-cut tile and stone blades | Ø180–350 mm, 25.4 mm arbor, fine grit, 10-12 mm segment | Tile saw, fabrication shop, contractor |
| Small-diameter wet cores | Ø25–100 mm, 5/8-11 UNC, sintered + silver brazed | Cost-sensitive handheld coring, retail |
Bond Hardness — Spec by Substrate, Not by Code
The most common procurement error in sintered diamond core bits is specifying the bond by code letter (M, H, MH) without naming the substrate. Bond hardness must match substrate hardness inversely: soft bond for hard substrate, hard bond for soft substrate. Hard, high-MPa concrete with dense aggregate wears the bond fast and exposes diamond continuously — soft bond is correct. Soft, abrasive substrates (asphalt, green concrete, soft brick) wear the bond out before the diamond — hard bond is correct.
For OEM RFQs, name the substrate explicitly: "C25-C35 reinforced concrete with #4 rebar" or "sand-aggregate masonry brick" or "asphalt over base concrete." The supplier matches the bond formula to your substrate description — this is more reliable than guessing the bond code letter.
RFQ Checklist
- Target substrate (concrete strength class, aggregate hardness, rebar density)
- Diameter range and quantity per size
- Arbor configuration (5/8-11 UNC, 22.23mm angle grinder, 25.4mm saw blade)
- Segment height (7-9 mm cost-sensitive, 10-12 mm premium)
- Diamond grit and concentration target
- Segment-to-body attachment method (silver braze standard, laser weld premium)
- Matrix hardness verification by Rockwell C measurement
- Witness cutting test on target substrate
- Max RPM stamp per blade size
- Packaging: bulk for distributor, blister card for retail, individual sleeve for premium
Trust Signals
- Matrix hardness verified by Rockwell C on production QC sample
- Diamond concentration documented per bond formula
- Silver brazing or laser welding attachment process per application requirement
- Witness cutting test on target substrate before mass production
- Max RPM stamp per blade per ANSI B7.1 or EN 13236
Build Your Sintered Diamond Core Bit Range
Send substrate description, diameter range, arbor, and annual volume. We respond with a sintered spec, bond match, matrix hardness verification plan, and quotation path.
Request Sintered Diamond Core OEM Quote