Wholesale Single Internal Coolant Hole Factory & Factories

A single straight axial internal coolant hole is optimal for single-lip deep-hole gun drills, precision reamers, single-point boring tools, and specialized end mills where fluid needs to exit along the core axis. Double helical coolant channels are engineered specifically for twist drills where coolant conduits must follow the flute helix ($30^\circ$ or $40^\circ$) to avoid flute break-through during CNC grinding. Single straight hole blanks offer significantly lower manufacturing friction, superior center-line laminar flow rates, and lower purchase costs per piece.

Concentricity is guaranteed at two stages: first during high-precision extrusion where core mandrels are aligned via laser centering fixtures to maintain total runout $\le 0.02\,\text{mm}$; second during centerless cylindrical grinding where workholding pressures and throughfeed wheels maintain uniform concentric ground outer diameters (OD) relative to the internal channel. Each batch undergoes ultrasonic non-destructive core inspection to certify that web-thickness variations stay within $\pm 0.01\,\text{mm}$.

For machining hardened tool steels, mould steels (up to 55–60 HRC), and difficult nickel alloys, our 10% Cobalt (Co) sub-micron grade ($0.6\,\mu\text{m}$ to $0.8\,\mu\text{m}$ grain size) is strongly recommended. It yields a Rockwell hardness of $92.0 - 92.5\,\text{HRA}$ alongside a Transverse Rupture Strength (TRS) exceeding $4,000\,\text{MPa}$. For interrupted cuts or extreme structural vibration, a 12% Cobalt ultra-fine grade provides the essential fracture toughness.

Yes. Our internal coolant channel bores are manufactured with an ultra-smooth internal surface finish ($Ra \le 0.4\,\mu\text{m}$). This prevents aerosol droplet agglomeration in MQL systems, delivering a precise air-oil fog mist directly to the cutting shear zone without premature condensation. Furthermore, our Sinter-HIP densified matrices tolerate severe cryogenic thermal gradients without micro-fissuring or binder leaching.

For catalog standard single-hole carbide rods (ground to h5/h6 or unground blank), the MOQ is 1 piece, and stock items dispatch within 24 to 72 hours. For customized dimensions—such as non-standard hole diameters, custom chamfers, specialized Weldon flats, or cut-to-length blanks—the initial sample validation lead time is 7 to 10 days, with full production batch lead times averaging 14 to 25 business days depending on volume.