Oval holes, tapered walls, or hole size that changes depending on which station ran the job. Here is how to work out what is actually causing it before you spend money on the wrong fix.
Holes that measure round on one axis and oversize on another. Walls that taper through the material. Or the same tool producing a good hole in one station and a poor one in another. Often it appears gradually — parts that used to pass inspection start getting rejected, and nobody changed the program.
Roughly in the order we encounter them. The first two are cheap to rule out, so start there.
A punch with a chipped or rounded cutting edge, or a die with a worn opening, will not produce a clean round hole regardless of the machine's condition. Inspect the punch and die under magnification before looking any further.
Clearance that suited mild steel will not suit stainless or aluminium of the same thickness. If the material or gauge changed and the tooling did not, hole quality changes with it.
If the die can move, the punch and die are no longer concentric at the moment of the stroke. Check that the die holder is clean, undamaged and properly seated.
This is the one that gets missed, because the machine looks fine and the tooling is new. Every punch stroke loads the upper turret station bore. After enough hits those bores wear out of round, and a punch sitting in an out-of-round bore is no longer held truly perpendicular or centred. The hole it makes reflects that.
Because the wear is in the machine rather than the tool, a new punch does not fix it — which is usually the point at which people start looking at the turret.
Move the tool, not the program. Take the tooling that is producing bad holes and run the same job from a different station.
If the bad holes follow the tool, the problem is the tooling or the clearance. If the bad holes stay with the station while the tool produces good parts elsewhere, the station bore is worn, and no amount of new tooling will fix it.
This is worth doing before anyone quotes you for anything — including us.
A worn bore does not have to mean a new turret or a new machine. The bore is machined to a precise oversize and a hardened USA-made steel sleeve is pressed in, restoring the station to Amada factory tolerance — typically within 0.0002″.
It is done at your facility, on the machine, with no shipping. Most jobs take 2–3 days of downtime and run $8,000–$25,000 depending on whether some stations or the whole turret need doing. For comparison, replacing an Amada turret punch press runs $100,000–$500,000+.
Read the detail on the turret sleeving page, or see how it compares to an OEM turret replacement in sleeve or replace.
There is no single number, because it depends on your tolerance requirements and what you are running. A shop holding ±0.005″ on mild steel brackets will live with wear that a shop doing precision stainless cannot. The practical answer is that when hole quality starts costing you parts, tooling or inspection time, the wear is already costing more than the fix.
Tell us the machine model and what you are seeing and we will tell you straight whether this is something we fix. If it is tooling or clearance, we will say so — we would rather point you right than sell you a service you do not need.
Free estimate within 12 hours. Work is typically scheduled within 30 days, and our engineers come to your facility — the machine never ships.
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