Guides / Sourcing
The Checklist for a Lab Equipment PEEK Drawing
September 26, 2026
Sources: manufacturer datasheets and published standards. See editorial standards.
A lab equipment PEEK drawing that looks complete on the CAD screen is often missing the five things that actually determine whether the part works: which grade, which thread standard, what pressure it has to hold, how clean the fluid path surface has to be, and whether it needs cleaning or passivation before it ships. Leave any of these off and the shop fills the gap with an assumption, and the assumption is not always the one you needed.
The five lines
| Line item | Why it matters | What to write |
|---|---|---|
| Grade | Unfilled, filled and bearing grades behave differently in a fluid path and under seal compression | Name the grade, not just “PEEK” |
| Port or thread standard | Lab fitting standards are not interchangeable even when threads look similar | Name the exact standard, referencing the instrument family if that is how it is specified |
| Pressure rating | Determines wall thickness, bore and whether the part is even feasible in PEEK | State the operating pressure and any test or burst pressure required |
| Fluid path surface finish | Rougher surfaces hold more residue and adsorb more analyte at trace concentration | State an Ra value if adsorption or cleanability is a concern, not just “smooth” |
| Cleaning or passivation | A part destined for trace-level or cross-contamination-sensitive use needs documented handling | State the requirement explicitly, or state that none applies |
Grade
PEEK for lab equipment is rarely one grade across an entire instrument. Unfilled PEEK is the default for wetted fluid path parts because it is the toughest and most chemically resistant of the family. Filled and bearing grades show up in structural housings, moving parts and anything that slides, where stiffness or wear resistance matters more than fluid contact. Naming the grade on the drawing, rather than leaving it as “PEEK,” is the single change that removes the most ambiguity from a quote. The tradeoffs between grades are covered in which PEEK grade should be on your drawing.
Port and thread standard
This is the line most often left implicit, and it is the one that causes the most expensive mistake: a correctly machined part that does not fit the instrument. Lab and analytical instrumentation uses several distinct fitting and thread standards, and two fittings that look nearly identical on a drawing can be dimensionally incompatible in the field. Name the exact standard the port has to mate with, and reference the instrument family or an existing fitting from that system if that is the clearest way to specify it. A shop working from a vague thread callout will make a reasonable guess, and a reasonable guess is not the same as the right answer.
Pressure rating
State the actual operating pressure the part sees in service, and separately, any pressure it has to survive without failing during a test or qualification step. This single number determines wall thickness, minimum bore size and whether the geometry you have drawn is even realistic in PEEK at all. How pressure and geometry interact with the tolerances a shop can hold is covered in what tolerances are realistic on a machined PEEK part.
Fluid path surface finish
A fluid path surface finish is not cosmetic. A rougher bore has more surface area for residue to sit in and more area for a trace-level analyte to adsorb onto between runs, which matters far more for a chromatography or sample-handling part than it does for a structural bracket. State a finish requirement, such as an Ra value, whenever the part is wetted and cleanability or adsorption matters. Leaving it unstated usually gets you whatever finish comes off the shop’s standard finishing pass, which may or may not be good enough for the application.
Cleaning and passivation requirements
Not every part needs this line, and that is fine to say explicitly. A structural bracket with no fluid contact typically needs nothing beyond normal shop practice. A part destined for trace-metal analysis, biopharma sample handling or any cross-contamination-sensitive use needs its cleaning and packaging requirement stated on the drawing, because a shop cannot infer a cleanliness standard from silence. State the requirement, or state clearly that none applies, so nobody assumes for you.
Confirming the resin behind the part
Once the drawing is right, the last variable is whether the material a shop machines actually matches what you specified. For anything trace-sensitive or a filled grade from a new supplier, it is worth confirming the resin itself rather than trusting the label. How to verify the PEEK you are buying is genuine covers what a certificate of conformance should show and when it is worth testing a sample.
Putting it together
Five lines: grade, port standard, pressure, fluid path finish, and cleaning requirement. None of it is exotic, and all of it fits on a drawing without slowing down the quote. What it buys you is a first quote that matches the part you actually needed, instead of a round of revisions after the shop guesses wrong on something you could have written down the first time.
The general version of this checklist, for any PEEK part, is in our guide to custom PEEK parts.
Ready to quote a lab equipment part? Send the drawing with these five lines filled in, and we match you with shops that machine PEEK for analytical and lab instrumentation.
Frequently asked questions
What thread standard should I specify on a lab fitting drawing?
Name the exact standard your instrument port uses, such as a flat-bottom or flangeless fitting standard common to a specific instrument family, rather than assuming a shop will infer it from a general thread callout. Lab fitting threads are not interchangeable across standards even when they look similar in a drawing.
Do I need to specify surface finish inside a fluid path?
Yes, whenever adsorption or cleanability matters. A rougher bore holds more residue and adsorbs more analyte at trace concentration than a finer finish does, and a shop needs the finish called out to know which finishing pass and tooling to use.
Does every PEEK lab part need a cleaning or passivation requirement?
No. A part with no trace-level or cross-contamination concern often needs nothing beyond normal machining. State it explicitly when the application does require it, since a shop cannot guess a cleanliness standard from silence on a drawing.
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