What This Product Does

The 1308 customized convex PDC cutters are diamond composite inserts with a 13.08mm diameter and a convex working surface, manufactured to customer-specified parameters for coal mining drill bit construction. The convex table geometry differs from the standard flat-table 1308 cutter by presenting a dome-shaped cutting face that concentrates cutting force on a smaller contact area, increasing point loading on the formation. This makes convex cutters particularly effective in coal seams with hard inclusions where higher localized pressure is needed to fracture stone bands and pyrite nodules.

Key Features & Technical Specifications

Cutter diameter: 13.08mm. Table geometry: convex with dome height adjustable from 0.8mm to 1.5mm (standard convex: 1mm). 

Diamond layer thickness: 1.8-2.0mm standard, 2.2mm available. 

Substrate: tungsten carbide with 6%-8% cobalt. 

Hardness: HRA 80-90 on diamond face. 

Thermal stability: up to 700 degrees C (thermally stable grade with TSP interface). 

Customization options: dome height, grit size, diamond layer thickness, substrate cobalt content, and interface geometry can all be specified by the customer.

Performance Advantages

Compared to standard flat-table 1308 cutters, convex cutters generate 25-35% higher point pressure on the formation at the same weight on bit, which translates to faster penetration through hard inclusions. In coal seams with 30-50 MPa stone bands, convex cutters maintain penetration rate 40-60% better than flat cutters after the flat cutters develop wear flats. The customized parameters allow bit manufacturers to tune cutter performance to specific seam conditions: higher dome for harder inclusions, coarser grit for more abrasive rock, and thicker diamond layer for longer service intervals. Custom-spec convex cutters extend bit life by 30-50% compared to off-the-shelf flat cutters in seams with frequent hard partings.

Application Scenarios

PDC drill bit construction for coal mines with hard stone bands, pyrite inclusions, or silica partings. Replacement cutters for rebuild programs on existing bit bodies. Bit manufacturers assembling custom bits for specific mining clients. For standard flat-table 1308 cutters suited to general coal drilling without hard inclusions, the 1308 convex PDC Cutters for coal mining button inserts for drill bit provides a cost-effective convex PDC cutter option for button-type drill bit inserts in coal mining. Development of prototype bits for new mining panels.

Problem-Solving Capabilities

Bit manufacturers and mine maintenance workshops often find that standard flat-table cutters wear quickly in seams with hard inclusions because the flat cutting face distributes force across the entire table area, generating insufficient pressure to fracture the hard inclusion. The result is cutter polishing rather than cutting, where the diamond face develops a smooth wear flat that skids across the inclusion surface without penetrating it. Convex cutters concentrate the same force on a smaller dome contact area, generating 30% higher localized stress that fractures the inclusion rather than polishing it. A bit rebuilder in Shanxi Province reported that switching from flat to convex 1308 cutters on their rebuild bits increased bit life in hard-inclusion seams from 180m to 280m, while maintaining penetration rate above 2.0 m/min through stone bands that had previously caused the bit to stall.

Technical Support & Customization

SUNGOOD TECH provides engineering consultation for optimal convex parameter selection based on seam geological data. Sample cutters available for testing before bulk orders. Minimum order for custom specifications: 100 pieces. Standard convex specifications available from stock with no minimum order.