Usage and Operation Views: 12

Yes, countersinks can machine blind-hole chamfers - be aware of the differences. Blind vs through holes: 1) Chip removal - through holes evacuate well (chips exit the bottom); blind holes trap chips at the bottom, which can press, scratch the finished surface, even jam the tool; 2) Depth - blind holes have a bottom; do not reach too deep, avoid hitting it; 3) Cooling - cutting fluid does not flow into blind holes well; cooling and lubrication suffer. Notes for blind holes: 1) Chip removal - a) interrupted feed (in 1mm, out 0.5mm, in again) helps chips out; b) flood cutting fluid, or high-pressure fluid to flush chips; c) pre-drill a chip hole at the bottom if allowed; d) withdraw periodically to clear chips; 2) Avoid collision - keep 1-2mm clearance above the bottom to prevent chipping; 3) Parameters - slightly lower speed and feed than through holes to prevent chip-blockage breakage; 4) Tool setting - set Z zero at the hole-mouth face, not the bottom; 5) Tool choice - standard countersinks work; use extended shanks for very small or deep holes; 6) Measuring - hard to measure inside; use dedicated chamfer gauges, a projector, or test with a screw. Techniques: 1) drill first, then chamfer - drill to depth first; never use a countersink to drill; 2) leave bottom stock - drill 0.5-1mm shy of depth so the countersink cannot touch bottom; 3) step chamfering - do blind-hole chamfers in 2-3 steps: cut, withdraw, clear chips, continue; 4) compressed air - blow chips out during machining (safety glasses!). Blind-hole chamfering is harder mainly due to chip removal - these methods solve it. Ask our technical team.