Drill bit supplier checks by hole application

Application cards with scene photos and site constraints

4140 through holes: coolant-fed versus solid carbide

Production drilling in 4140 often forces a choice between a coolant-fed blank that clears chips and a solid-carbide grind that is cheaper to regrind. A coolant-fed quote is not comparable if the oil-hole diameter, shank collar or holder is missing. A solid-carbide quote is not comparable if pecks, web thickness and point angle stay silent. Keep ±0.025 mm on diameters that control location; open non-critical lands so grind hours do not inflate every feature.

Construction: bond and coolant as delivery stages

State whether bits ship as dry, wet, or vacuum-ready. A factory quoting only a sintered blank is not quoting the same job as a factory quoting laser-welded segments and a named diamond grit.

Mining: geometry must match the hole and the rock

PDC cutter size, tricone IADC class, or DTH face design belong on the RFQ. A mining drill bit manufacturers quote without rock class and flushing method is not comparable.

Offshore versus domestic total landed cost

A lower piece price from a distant shop can reverse after freight, duty, extra FAI travel and a longer change-control loop. A domestic shop can still lose if carbide rod or diamond grit is imported and quoted as a surcharge. Compare one Incoterm and one destination; do not publish a percentage gap. This page does not treat either side as already chosen.

Hole-location Cpk and the tight-tolerance cost curve

Hole-location Cpk asked of the plant is a process-capability number measured on the buyer fixture, not a slogan this desk can reprint. Sample bits may be uncoated or hand-finished; production lots may require a named PVD batch. Awarding a production EAU from a sample-only price cell mixes unlike processes. Keep prototype quantity, production lot and annual usage on separate lines. If Cpk is required, write the sample size, the CMM method and whether Ppk is also requested.