Surface Figure
Surface form tested by interferometry — PV/RMS values from the actual measurement.
Standard Size · Made to Print
2.78 x 29.00 mm Rod Lens — Standard Size, Made to Print
This 29.00 mm relay step is already in production. Send the drawing and get a fit check, tolerance review and quote within 24 hours. No custom-quote wait. Supplied as uncoated rod lens blanks for coating laboratories, or finished per your drawing for OEM assembly, with a measured batch COA. It is the most frequently requested pairing in the 245-size database, used where a 29 mm relay step meets a 2.78 mm tube opening.
✓ ISO 9001:2015
✓ NDA Protected
✓ COA per Batch
✓ MOQ 10+
✓ Quote in 24h
Quick Answer: Φ2.78 × 29.00 mm is a proven production size, supplied uncoated for coating labs or finished per drawing for OEM assembly. Diameter −0.02/−0.04 mm, centration ≤3′, batch COA with measured values, MOQ 10.
Specifications
Standard Specs — Confirmed Against Your Drawing
Final tolerances, glass grade and build type are confirmed against your drawing at quote.
Size Positioning
Where Φ2.78 × 29.00 mm Sits in the Range
Φ2.78 × 29.00 mm pairs a 2.78 mm outer diameter with a 29.00 mm relay pitch, a combination used in rigid endoscope relay trains where the relay step and tube diameter are both mid-range. Because this pairing is already in production, the review starts from a known process and moves straight to drawing confirmation.
In typical rigid scope builds, this size appears as a relay rod between objective and eyepiece optics; the drawing usually specifies centration datum and edge chamfer.
Design Notes
What to Confirm for Φ2.78 × 29.00 mm
Design note: at Φ2.78 × 29.00 mm, the 29 mm pitch and 2.78 mm diameter are balanced for a standard rigid relay train; check the drawing for end face squareness and chamfer requirements.
Two Supply Paths
How We Supply Φ2.78 × 29.00 mm
For Coating Laboratories
We supply Φ2.78 × 29.00 mm as uncoated blanks with the −0.02/−0.04 mm diameter fit held on the ground surface, ready for coating-lab chamber loading without rework.
For OEM Assemblers
For OEM assembly, we finish Φ2.78 × 29.00 mm rods to your drawing and confirm centration, surface quality and glass grade before production.
Real Production Photos
Φ2.78 × 29.00 mm in Our Production
Photos are production references; final dimensions follow your drawing.
2.78 diameter reference
29.00 length reference
Proven Size
Why Φ2.78 × 29.00 mm Is a Standard
This pairing carries the most production history in our database: the diameter/length combination has been drawn, machined and measured across repeated batches, so feasibility is already answered before your drawing arrives.
Drawings first. A drawing is always the fastest way to a precise match — send yours and we take it from there.
In-house production
Factory Checks for Φ2.78 × 29.00 mm
You can verify Φ2.78 × 29.00 mm against our production records: centration is measured per ISO 10110-6 and the value is printed on the batch COA.
ISO 9001:2015 quality system
In-house since 2009 — no reselling
Measured COA per batch
NDA standard before drawings
24-hour engineer quote
MOQ 10 · glass never substituted
Quality Evidence
Φ2.78 × 29.00 mm — The Numbers Go on Your COA
For Φ2.78 × 29.00 mm, the batch COA carries measured diameter, length and centration, plus surface quality and test method.
Inspection & Metrology
We measure it — and the numbers go on your COA.
Every batch is verified with interferometry, centration measurement and surface inspection. You get the actual measured values, not a “within spec” checkbox.
Centration
Centration checked on the centration station, typically ≤3′. The reading shown is from a real part — 2.02′.
Surface Quality
Surface and edge quality inspected under a video microscope — scratch/dig per MIL-PRF-13830B.
What “Pass” Looks Like
A passing surface from a production run: PV 0.51λ, RMS 0.059λ. Rejects never leave the workshop.
Measured COA per batch — ask for a sample COA with your quote. · Learn how to read a surface map →
Real inspection record from this product line
Workstation record from a Φ2.78 × 29.00 mm relay rod batch — PV 0.51λ.
Real measurement, kept on file. Your COA gets the same kind of data.
FAQ
Common Questions for Φ2.78 × 29.00 mm
Is Φ2.78 × 29.00 mm a stock size?
Yes, it is the most requested standard size in our database and is manufactured to order with MOQ 10+.
Can you supply it uncoated for a coating lab?
Yes. We ship it as an uncoated blank with the diameter fit held for direct chamber mounting.
What tolerances apply to this size?
Diameter −0.02/−0.04 mm, centration ≤3′, surface quality 40/20, edge chipping ≤0.05 mm, confirmed against your drawing at quote.
Why is this pairing so common in rigid scopes?
A 2.78 mm diameter clears standard rigid tubes while the 29 mm pitch keeps relay count practical; the combination is proven across many builds.
Do you provide documentation with this size?
Batch COA with measured values plus material certificate per shipment.
Related
Related Sizes for Φ2.78 × 29.00 mm
Standard Rod Lens Sizes
Full 245-size database, by family.
Rod Lenses — Product Range
Relay and rear rods, Φ1.19–8.0 mm, per drawing.
Applications
Hysteroscope, cystoscope and slim rigid scope optics.
Factory Video
Tour the Factory for Φ2.78 × 29.00 mm
Watch Φ2.78 × 29.00 mm go through the same grinding, polishing and measurement steps as the rest of our production.
See the Factory Live — Schedule a Video Tour
Watch rod lens grinding, polishing, centration measurement and final inspection in real time. All information shared during the tour is confidential — your NDA is welcome.
Schedule a Live Video Tour