Most “PCD accuracy” complaints trace back to the holder, the clocking or the assembled runout, so check those before blaming the PCD edge. Preset length and Ø offsets, verify clocking where the process needs it, measure assembled runout at agreed positions, and after reconditioning re-apply compensation before volume. First-article release should lock this checklist, not tribal memory. Send holder type, gauge length, and runout readings with the bore scrap mode. HENTRY reads that pack, writes sample acceptance, and stays on first-off (sample validation → Custom Cutting Tool RFQ).
First-off comes off lobed. Someone blames the diamond. The holder taper still has yesterday’s swarf, clocking was “close enough,” and nobody measured assembled runout at the stickout the machine actually uses. The edge never got a fair trial.
Use the checklist below to preset, clock and check assembled runout on a PCD reamer, from unboxing to first article and again after a regrind. For how the tool itself is made, see how PCD reamers are made; for when to regrind and how to requalify, see when to regrind and how to requalify; and to check the edge itself, watch the cutting-edge inspection video.
1. Unbox, clean, look—before the spindle
Do this on the bench, not after the first scrap tag:
- Confirm tool ID and drawing revision match the job traveler. A “same reamer” from last month may be a different grind.
- Wipe shank, taper, and coolant ports. Swarf in a collet or HSK face is assembled runout you have not measured yet.
- Visual: PCD lips, pads/pilots, obvious nick or raised braze. If the edge is the question, watch cutting-edge inspection and photograph what you see.
- If this tool just returned from service, stop and open the regrind / requalify release note before you copy last month’s offsets.
Holder hygiene and projection habits for create tools are written on carbide drill stickout, runout, and toolholders. The same stack logic applies to a reamer: clean interfaces, only as much stickout as the bore needs, measure the assembly you will actually run.
2. Preset and clocking—fields to record
Preset is not “length looks right in the setter.” Write the fields the control and the gauge will use:
| Field | Record | Why it bites later |
|---|---|---|
| Gauge / projection length | Setter value + where it was taken | After regrind the body is shorter; old Z will crash or rub |
| Diameter offset / wear offset | Value + which Ø / step it belongs to | Multi-step tools need a named offset per finish Ø |
| Clock / orientation | Mark vs holder, spindle, or pad clock if the process uses it | A guided or stepped body that is clocked wrong loads one land |
| Holder class + ID | ER / hydraulic / shrink / other + holder number | Published holder TIR is not assembled TIR |
| Setter vs spindle | Which machine, which taper, who signed | A pretty setter number can die on a dirty spindle |
Clocking matters when pads, a pilot, or a step relationship have a preferred orientation—or when you are matching a previous approved assembly. If the process does not use clock, write “not required” so the next shift does not invent one.
Product geometry still comes from the custom PCD reamer drawing, not from a setter default.
3. Assembled runout: where to measure, how to accept
Measure the spindle–holder–reamer stack at the stickout you will cut with. A bench arbor number is a screening value, not the production number.
Where (agree and repeat):
- Near the cutting section (as close to the PCD lips as you can do safely).
- On a guide pad or land if the tool uses one—the bore will follow that contact.
- At a second axial station if the body is long; angular error grows with length.
Holder catalogs publish a component TIR. Once you add a collet, reducer, or extension, the number that matters is cumulative assembled runout at the edge. Errors are directional—they can add or cancel when you clock a component—and length magnifies an angular miss. If the holder type itself is still open, start with toolholders for PCD reaming.
How to accept the reading:
| Question | Accept path |
|---|---|
| Is there a number on the tool drawing or control plan? | That number, at the stated position, wins. |
| Is the scrap mode lobing, one-edge wear, or oversize on a “new” tool? | Treat assembled runout as the first suspect—fix the stack before you redesign the diamond. |
| Did quality collapse only after a holder or stickout change? | Restore the previous assembly as a controlled test. |
| Is there a standard µm band to copy? | No universal band applies. Write the plant number. |
For measurement practice on the drill side, which gets stricter as the diameter shrinks, see stickout, runout, and toolholders. Do not import a drill TIR slogan onto a finish reamer and call it validated.
4. After regrind: compensate again
A reconditioned reamer is a new offset event. Stock came off the lips; length changed; sometimes a pad was restored.
Before volume:
- 1. Confirm the service release against regrind and requalify (Ø, runout, pads, edge).
- 2. Re-preset length and Ø. Do not copy the pre-service wear offset.
- 3. Re-check assembled runout on the same holder you will run.
- 4. Re-clock if the process uses clock.
- 5. First-article on the written gauge plan—then release.
If the shop “just put it back in” and the bore moved, the missing step is usually this list, not a new PCD grade.
5. First-article → sample validation / RFQ
Lock the checklist in the traveler:
- Tool ID / revision / service state (new or post-regrind)
- Holder class, ID, gauge length, clock
- Assembled runout: value, position, instrument
- First-article bore result vs the written accept list
- Who signs release
It follows the same rule as sample validation: write pass/fail before the argument. For manufacturing control on a new tool, see how PCD reamers are made; for buyer questions on inspection evidence, the buying checklist; and for other special tools, custom cutting tools.
Setup RFQ pack
- Holder type/class and spindle interface
- Gauge / stickout length
- Assembled runout readings and where they were taken
- Bore scrap mode (lobe, taper, oversize, chatter marks)
- Drawing + material + whether the tool is new or post-regrind
Prepare the fields with the PCD Reamer RFQ Checklist, check the Custom PCD Reamer, then send them through the Custom Cutting Tool RFQ.
The first-off that failed on a dirty taper is a setup story. Send the holder and gauge data; HENTRY will not start by inventing a sharper diamond.
Frequently Asked Questions
Where should assembled runout be measured on a PCD reamer?
On the assembled spindle–holder–tool stack, as close to the cutting section as you can do safely, at the stickout you will run. If the tool has a guide pad or land, measure that contact too. A setter arbor number is a screen, not the production value.
Do I need to re-preset after every regrind?
Yes—treat a serviced tool as a new offset event. Length and Ø move when stock comes off. Re-preset, re-check assembled runout, re-clock if the process uses clock, then first-article. Return triggers and the fields to requalify are covered in the regrind guide.
What runout is “good enough”?
The number on your drawing or control plan, at the stated position. There is no universal micrometre band. If scrap is lobing or one-edge wear, fix assembled runout before you redesign the PCD.
What data belongs in an HENTRY setup RFQ?
Holder class and interface, gauge/stickout length, assembled runout readings and positions, bore scrap mode, drawing, material, and whether the tool is new or post-regrind. Put them in the RFQ, using the RFQ checklist as the field list.
Next step
Close the job with a traveler that already has the holder ID, the runout position and a name on first-article.
- To check the edge, watch the Cutting-edge inspection video; for how the tool is made and what to ask a supplier, read How PCD reamers are made and the Buying checklist; for the drill side, see Stickout / runout (drill practice).
- After a regrind, follow PCD reamer regrind and requalify.
- For the tool itself, see Custom PCD Reamer.
- To release a first article, agree the terms under Sample validation, then fill in the PCD Reamer RFQ Checklist and send it through the Custom Cutting Tool RFQ.