A buyer searching for HMC is usually trying to stop a bad substitute. A CNC machine is specified by travels, spindle or process, accuracy, control, and the parts you will actually cut. The notes below are selection criteria for a HMC. They are not a catalog promise. Confirm every rating on the current datasheet, drawing, or test report for the revision you will receive.
What has to be true of HMC
A CNC machine is specified by travels, spindle or process, accuracy, control, and the parts you will actually cut. For a HMC, start from the duty, then the interface to the rest of the machine or the room, then the document that proves the claim. A lower price that leaves one of those blank is a different product.
HMC is easy to confuse with CNC Controller. If the quote could be read as either, add the line that separates them: the rating, the fitment, or the standard named below. Link the drawing number to that line so receiving inspection can reject the wrong one.
Numbers that change the quote
| Line | What to write for HMC |
|---|---|
| Tooling and table | Taper, table size, or the chuck. |
| Utilities | Power, air, and foundation. |
| Travels | X, Y, Z, and any rotary, in the work envelope you need. |
| Process | Mill, turn, laser, plasma, or EDM, with power. |
| Accuracy | Positioning accuracy and repeatability, and the method. |
| Control | The control name and who can edit the program. |
How to compare two offers
Lay both quotes for HMC on one sheet and line up tooling and table, utilities, and travels. If a cell is empty, the offer is not finished. Ask for the missing line in writing. When those match, the honest difference is lead time, the test evidence, and who carries the warranty. Do not average a fully specified HMC with a cheaper line that omitted tooling and table.
Documents worth having before the deposit
Ask for an accuracy statement and a layout with service space. The file should name HMC and the revision, not only the supplier’s homepage. A factory quality certificate such as ISO 9001 can sit beside that file. It does not replace it.
Failures that show up after delivery
- Understating spindle power for the material.
- Buying travels that the fixture then consumes.
- Ignoring the control your programmers know.
On a HMC, the expensive version of the first mistake is discovering it after the goods are in the crate. Put the rejection condition in the purchase order while the supplier can still restate the offer.
A worked RFQ line
Use this shape, then replace the brackets with your duty: “HMC — State travels, process and power, accuracy, control, and utilities.” That sentence is a template, not a rating of any brand. If a supplier’s datasheet uses different units, convert them onto this sheet so the next offer can be compared.
Where words like RoHS / CE belong
Searches often add a constraint to HMC: RoHS / CE, or outdoor. Keep those on this page. RoHS is a material limit. CE is a declaration that lists the rules relied on. Ask for the document that names this part number and revision. Outdoor means UV, temperature cycle, and corrosion, not only a gasket. Name the climate and the years the gasket is expected to last. If you need a third constraint, add it as another line on the same drawing. A second URL that only swaps the adjective does not give a buyer a second fact.
Related in this section: how to specify CNC Controller.
Questions buyers actually ask
What should an RFQ for HMC include?
State travels, process and power, accuracy, control, and utilities.
Is a cheaper HMC the same part?
Only if tooling and table, utilities, and the documents match. A missing line is a different offer.
Do waterproof, OEM, or IP words need their own page?
No. For HMC they are extra lines on this specification. Ask for the test or the drawing that gives the word a value.